Icom IC-R1:

Icom IC-R1:
The ultimate review, modification & restoration guide.
From Jason Reilly
Icom’s IC-R1: 0.1 to 1300 MHz in your pocket.
Contents of this article:
• Review of Icom IC-R1
• Restoration
• Change the display backlight colour mod
• Brighter RX indicator LED mod
• Improving selectivity with 2nd & 3rd IF filter change mod
• Eliminating images mod
• Even out AM/FM volume difference mod
• One handed Function button mod
• More than 100 channel memories or frequency expansion mods?
• Restoring 800 MHz or other blocked bands mods
• Activating a hidden 'auto' mode
• Faster scan rate mod
• Adding SSB reception mods
• A real discriminator tap mod
• Faster internal battery charge mod
• Bigger capacity internal battery mod
• Better shielding mods
• Available accessories
• Analysis of included FA-4B flexible antenna
• Common faults and their repairs
• Disassembly and reassembly tips
• Information about related online instruction & service manuals
• Comparison of IC-R1 with a modern day micro-mini receiver
• Conclusions
Brief specifications:
Frequency range: 0.1 to 1300 MHz. (some had country specific blocked frequencies)
Memory channels: 100
Search banks: 10
Scan / search speed: measured at 20 channels / frequencies a second
Modes: AM, FM, Wide-FM
Dimensions: 49 x 103 x 35 mm, 280 grams
Features: signal strength meter, clock/timer, priority, autostore, flexible scanning options
Manufactured: Japan, released December 1989, discontinued late 1993, but may have still been
available at dealers as late as 1995 when superceded by Icom IC-R10.
Background & perspective:
Some of the things my dad would do, I couldn't quite understand as a young boy. Trained as
a motor mechanic, dad would buy complete wrecks of cars from the 1950s or earlier and spend
anything up to three years lovingly restoring each of them to their former glory. Something of an
alchemist, he would be working in the garage turning twisted, rusty bits of metal into something
useful for his A-model Ford or '57 Chevy coupe, while I'd be at the workshop bench, a hot soldering
iron in hand building up the latest Dick Smith electronic kit that once was pocket money in a 10
year old's piggy bank. I remember thinking how much effort dad put in to these old cars, and how
at the end of it all, he'd end up with a car that was drivable and looked neat, but hardly as
comfortable or fuel efficient as a modern day car. Driving a 1940s car in a 1980s world wasn't very
practical, I thought. Meanwhile, the labour of my efforts produced something 'way cooler' – or at
least it seemed that way to one 10 year old boy at the time – things such as an electronic dice or a
kitchen egg timer.
But now, I'm on a restoration mission of my own. An Icom IC-R1 pocket sized
'communications receiver' – a scanner by any other name – has landed in my letterbox, and while it
works fine, it certainly isn't what you'd call in 'factory fresh' condition.
As that ten year old boy grew older and got his first job, so did the 'pocket money' grow. As
a result, various models of scanner came & went, always looking for a radio that I'd be happy with.
Scanning back then was a pretty simple affair: no trunking, certainly no digital radio transmissions,
heck, even analogue cellular mobile phones were yet to arrive in these parts. Likewise, scanners of
the time were also pretty simple; your main choices for years were 'do you want 10 or 50 memory
channels' and 'would you like airband reception with that, sir?' Then in the late 1980s, scanning
radio receiver technology started to take off. Tandy / Radio Shack & Uniden started to bring out
models that had 800 MHz reception in them as well as airband reception as standard. Yupiteru
came out with the MVT5000, that people were calling the first 'super scanner' with reception from
25-550 and 800 -1300 MHz coupled with AM & FM reception modes independently user selectable
on any frequency, giving hobbyists access to some pretty interesting slices of the spectrum for the
first time in a handheld. Not to be outdone, AOR soon released their AR1000 which had a mindboggling 1000 memory channels and 8-600 and 805-1300 (later 0.5-600 and 805-1300) MHz
reception.
The Icom IC-R1 in review:
Icom couldn't let this challenge go unanswered, and in December 1989 released to the world
the IC-R1. It pushed the frequency coverage envelope even further: 0.1-1300 MHz with no gaps,
and a reasonable 100 memory channels, plus some new features never before seen on a handheld
scanner such as a built in clock which could turn on or off the radio at a pre-determined time, a
snazzy little RX indicator LED, a ten segment signal strength S-meter and a line-out socket for
recording things you hear. Of course it just wouldn't be an Icom without the range of accessories
available such as a desktop drop in charger, slide-on extended capacity battery packs and protective
leather cases. But the most noticeable aspect of the IC-R1 is also the smallest: its size! The R1 was
two and a half times smaller (by volume) than the average scanner available at the time. And
naturally, I just had to have one. In 1990, it cost around $750 from a genuine Icom dealer to own
one (around $1400 in today’s terms) so it wasn't cheap, though by shopping at non Icom authorised
outlets you could shave off a few dollars. Compare that with $429 for a Uniden BC-200XLT, $499
for a Yupiteru MVT5000 or $599 for an AR1000 at the time.
The little Icom certainly had lots to endear itself to scanning folk. Stylish good looks,
Icom's famous build & finish quality, innovative features and unparalleled frequency coverage in a
handheld smaller than anything ever seen before. Multiple reception modes are at the complete
control of the user with AM, FM and WFM available no matter what frequency you’ve entered, and
coupled with multiple step sizes of 500 Hz, 5, 8, 9, 10, 12.5, 15, 20, 25, 30 & 50 kHz, you could
cater for just about any listening requirement. Icom didn't skimp in the sensitivity department,
either, with excellent ability to pick up weak signals even by today's standards – though like most
other wideband scanners, the R1 becomes quite deaf towards the edges of it's frequency coverage.
The built-in battery pack that sits behind the keypad is rated at 300mA/h and is good for listening
for about three hours of average listening, and if that isn't enough, you can call upon several battery
saving features to increase your listening time. For example the receiver power-saving ‘sleep’ time
can be set between five different levels, the little RX busy LED above the LCD can be disabled, and
even the key beep can be turned off. To top off all this flexibility, the user can also adjust the LCD
contrast, and set the IC-R1 to resume scanning either 2 seconds after a signal has disappeared or
resume regardless 10 seconds after it has stopped at a signal. Scanning speed is switchable between
10 and 20 memory channels a second, and there's the usual LCD backlight which evenly illuminates
the display in a pleasing green light.
Icom IC-R1 size compared to Uniden UBC-200XLT: is bigger always better?
But there were some oddities about the IC-R1 too, however. Memory 'banks' were nowhere
to be seen on the little Icom, but the user was compensated with some flexible scanning options:
you could nominate scanning between any two specified memory channels, or scan only AM or
only FM frequencies, and you could selectively skip memory channels too. Confusingly, Icom
called the process that we normally know as 'searching' with the term 'programmed scan' – but a
search never the less it is, and you can designate ten individual search ranges to seek 'n destroy your
frequencies. Another type of search will automatically store whatever active frequencies it finds
during a search into memory locations 80-99. Unfortunately when you start this type of search, the
microprocessor automatically deletes memory channels 80-99 in preparation for storing whatever it
finds. That makes these twenty memory locations of somewhat limited use for 'everyday' scanning,
unless you plan on never using the auto memory write scan feature. Another handy facility is the
ability to nominate up to 60 frequencies that will be skipped in programmed scan (search) mode...
but those frequencies have to come from somewhere, and they occupy memory locations 20-79. So
if you want to skip any frequencies during your searches, you have to program them in to one of
those memory locations and 'skip' that memory first – biting further still into your precious 100
memories. You could still use all 100 memory channels for normal scanning of course, but if you
wanted to take advantage of some of these other features, some memories had to be sacrificed to the
cause. The priority feature of the IC-R1 is a little different to what you might expect as well: rather
than sampling a 'priority channel' periodically, Icom ask you to enter your priority frequency into
the VFO. Then, once the priority feature is activated, the R1 will alternate between your priority
VFO frequency and a memory channel that you also want to listen to. Things get even more
interesting in memory scan mode, where the VFO priority frequency is sampled in between each
and every memory channel being scanned i.e.: ch 1, priority, ch 2, priority, ch 3, priority, ch 4 etc.
Something else that isn’t quite right on the IC-R1 is the squelch action. Normally, squelch action is
very definite, and you can set the squelch control to a ‘knife edge’ on most receivers to ensure the
very weakest signals are heard. The IC-R1 squelch is a little indecisive; if you set the squelch to
where it is just closed – the so called ‘knife edge’ setting, you’ll find the IC-R1 squelch pops open
and closed ever so slightly. This means you have to advance the squelch somewhat past the knife
edge point for reliable operation. Thankfully, weak signals are not missed due to this. Another
oddity is that in AM mode, the S meter will never read above S9 no matter how strong a signal is
pumped into it, whereas FM & WFM readily will.
So that covers the good & the quirky. What about the bad? If you have big fingers, you'll
immediately notice that the tiny keypad buttons are a little awkward to push, and the small knobs on
the top panel are similarly also not designed for fat digits. However the worst aspect of this
miniature scanner is that it is prone to reception problems. The IC-R1 is impressively sensitive
across most of the bands and while the 150 milliwatt audio output won’t blow your eardrums to
pieces, it sounds clear and articulate enough. No, the big problem with the IC-R1 is that it has some
major issues with selectivity. Often a 'phantom' signal is received on a displayed frequency that
simply isn't really there. If you've experienced 'image frequencies' on other scanners before, you'll
know what this is all about. The IC-R1 is, unfortunately, plagued by similar issues. While this
might not be a problem for users in a small country town where radio signals are few and far
between, users in a major metropolitan city or close by to a radio transmitting station will soon be
tearing their hair out. As an example, let’s say you are listening to a moderately strong signal on
164.000 MHz. As you tune around this frequency, you'll hear that same signal again on every
frequency from 163.750 MHz through to 164.300 MHz. The stronger the signal, the worse the
problem gets spreading out to more and more phantom frequencies, and is worst about 190 kHz
away from the real frequency, where the real signal only has to be -100dBm or around 2 microvolts
(about an S3 on the R1's signal meter) for it to begin to appear as a phantom signal. Technically
speaking, this isn't actually an 'image' problem, its a problem with the third IF ceramic filter
'spurious response' that all ceramic filters exhibit to some degree, though normally this is negated
by clever receiver design. Unfortunately Icom had to cut some corners to make the IC-R1 so small,
and had to sacrifice something. This can be vastly improved upon by a modification, read on below
for this.
And then there are genuine image issues too, where signals appear 21.4 MHz above or
below the real frequency, which is a problem not often seen in a triple conversion receiver. Again,
we can perform modifications to eliminate these images, which is detailed later on. So in terms of
signal selectivity and interference rejection, the IC-R1 is a real compromise. Some would argue
that it sacrifices too much in this regard, and I tend to agree with this sentiment.
The birdie count on the Icom IC-R1 is moderately high, with 210 birdies noted in a sweep
between 5 to 1000 MHz. A number of birdies are expected with wideband receivers, and the IC-R1
isn't the worst performer in this regard, but it certainly isn't remarkable.
There is still one aspect that hasn't yet been discussed about the IC-R1: it's abilities on the
HF or shortwave bands. Here another couple of problems comes to the fore: the IC-R1 has a very
'noisy' receiver in this part of the spectrum. Internal microprocessor noises & birdies are found in
copious quantities below 30 MHz, in fact there's almost constant noise on just about every tuned
frequency below 4 MHz - even though the HF portion of frequency coverage only represents 2% of
the total the IC-R1 can cover, birdies below 30 MHz represented 20% of all birdies recorded. I also
found multiple FM broadcast stations were mixing together in the front end and producing their
sum differences in the HF band e.g.: a particularly strong FM broadcast signal on 93.3 MHz mixes
with another station on 103.7 to produce a weird mish-mash of the two stations on 10.4 MHz – and
every strong FM broadcast station will mix with another, potentially creating dozens of mixing
products across the HF band. Combined with the 3rd IF ceramic filter spurious response issue
identified above, and you can see that tuning through the HF band isn't going to be a pleasant
experience on the little Icom. In laboratory conditions, the IC-R1 is impressively sensitive at HF,
yet it is barely adequate to listen to any but the very strongest of shortwave broadcasts, anything
weaker is masked by spurious mixing products & internal noise. You could use a larger antenna to
capture more signal, and the IC-R1 will certainly then receive more shortwave signals, but then
you’ll exacerbate the interference & selectivity issues. I found that a telescopic whip was an
excellent choice for HF reception on the R1 – you could lengthen or shorten the antenna as the
situation demands it – longer for capturing a better signal, or shorten it to reduce the amount of
interference & overload received. HF reception - and VHF lowband reception for that matter - is
also noticeably improved if you have the IC-R1 held in your hand or sitting on a large metal surface
while listening to act as a ground counterpoise. Down very low in the HF bands, the IC-R1 is very
insensitive, to the point that on a test drive with the little Icom, it needed to be within 100 metres of
a 500 watt NDB on 300 kHz to be received with the stock antenna. And what about SSB? There is
none. Tantalising clues exist that Icom may have originally planned to equip the IC-R1 with SSB
(why else would they have gone to the trouble of including a 500 Hz step on a radio such as this?)
but clearly decided against it in the end. Adding in SSB reception is possible, via a modification
detailed below, however.
Having purchased & owned the Icom IC-R1 from new back in 1990, despite its faults it
became a talkative companion that I could (and did!) carry just about everywhere with me. We'd
had some adventures together in those few years, but in the end I decided that it was time to move
on to another scanner. I never regretted that choice, but all the same, I did miss the little Icom. It’s
funny how we become attached to inanimate objects and begin to talk of them as though they were
long lost friends, isn't it?
Restoration tips:
Present day. A bit of disposable income and sentimental nostalgia combine to once again
fuel the desire for me to get another Icom IC-R1. Like any radio that is getting on to 25 years old,
finding one that is in excellent condition is not easy. Most will require at the very least a new
internal battery pack; the IC-R1 that I have recently received is no exception. The good news here
is that the original 300 mA/h pack can be substantially improved upon with 600 and even 750 mA/h
capacity replacement packs being available that fit into the same space. The battery pack has an
inline connector, making replacement no more complicated than undoing the screws that hold the
R1 together, pulling apart the case halves, removing the old pack and plugging in the new one.
Another item likely to need attention in the R1 (and many other radios from this era) is the
backup lithium battery. If the battery is so old and run down, it may be shorting out the backup
power line to the microprocessor, sometimes to the point of preventing it from starting up properly.
In theory, charging the internal battery should also charge the lithium cell. A good charge
overnight, then resetting the IC-R1 by holding the “F” key on the side of the radio, and the “CL”
key top right of the keypad, while turning on the radio power, should see things right again. If not,
de-solder the old CL2020 lithium cell, and replace it with a new VL2020 cell (CL2020 cells are no
longer available).
Something else that can cause problems over time is the power connector on the top panel
and the battery contacts for the extension battery packs on the bottom of the radio. Both contain
internal change-over contacts that can become dirty or contaminated, which results in the radio not
powering up or not charging. To fix this, you'll need to remove the internal battery pack and then
flood the top power connector with electronic grade contact cleaner. Immediately 'exercise' the
contact by plugging in and removing the charger power cable (making sure it isn't plugged in to the
wall outlet!) to help shift any dirt. Then finish off by using some electronic grade cleaning solvent
this time to rinse away the dirt, let everything dry off for a good few hours, and reassemble. If the
bottom extension battery pack contact is suspect, the same principle applies: remove all power
sources, flood with contact cleaner, rinse with solvent, let dry & reassemble. The critical contact
here is hidden in behind the larger gold coloured spring leaf. Icom themselves had predicted this
would be a problem with the IC-R1, and they warn the user to always use the protective dust cap
that covers the power / earphone / line out connectors to prevent dust ingress. Good advice! If you
have lost yours, non-original replacements can be purchased on the internet.
To get the exterior looking good again, a soft damp cloth and some patience is all that is
needed to wipe away years of grime. Go slowly here, you don't want to rub off any labels or
imprinting. A soft paintbrush helps remove dust in some hard to reach spots, and a very soft
toothbrush will be invaluable to removing any built up dirt in grooves around LCD display lenses,
flutes in dial knobs or gaps in between case joins. Scratches in LCD display lenses can be buffed
out very carefully with a rotary 'Dremel' tool and the softest buffing wheel you can get your hands
on – though beware this can also remove any nearby printed labels, or change the appearance of any
matte (anti-reflective) finish to the LCD lens / window or its surrounds. Heavy scratches can be
polished out with some plastic polish or even gel toothpaste if the scratches are really bad, but
there's a bit of an art to this, so practice on some scrap bits of clear plastic first before attempting the
real thing.
My IC-R1 had paint flaking off the back case half. On the inside of the bottom cap (to cover
the extension battery pack contacts if you’re not using an extension battery) of my IC-R1 was a
sticker proclaiming it to have been calibrated. There wouldn't be too many organisations out there
that would want to have a device like this calibrated for official use. I'd heard stories that the
ACMA used Icom IC-R1 scanners taped to small yagi antennas for finding rogue signals. The paint
wear on my IC-R1 seems consistent with that, and with that calibration label underneath... perhaps
this particular R1 has some very interesting heritage to it?
A calibrated Icom IC-R1? Ex-ACMA perhaps?
On the R1, the front half of the case is a good quality plastic, but the back half is a die cast
aluminium shell, and painted a satin-to-almost-matte black to match the front case half. Thankfully,
there's no printed labels on the back half of the case, this opens up the possibility of completely
stripping the paint away and repainting afresh. Removing all the electronics from the back case half
is a fiddly job, but necessary if you're going to make a good job of repainting it. The first step in
disassembly is to remove the bottom cap or any extension batteries you have attached, then undo
the screws indicated here:
How to correctly open the IC-R1 case:
Carefully pull apart the case halves, and you'll note the two are joined by some flexible ribbon
cable. There's enough of this ribbon to act like a hinge to be able to lay the two halves flat,
preferably on a soft cloth to prevent scratches to the case. At this point, I definitely recommend
carefully removing the extension battery pack retaining clip and it's tiny spring – beware that this
spring will want to fly out to freedom like a caged bird, and you do not want to lose this spring.
Also remove the internal battery and the grey rubber backlight button. I like to place screws,
springs, clips etc. in a resealable plastic bag to keep things nice & safe.
Now it's time to warm up a small soldering iron and pull off the antenna connection wire link from
the BNC connector to the mainboard. It's right about now that you'll realise just how little room
you'll have to manoeuvre a soldering iron inside the gizzards of the IC-R1, and that I really am not
kidding when I tell you that you'll need a small pencil sized soldering iron for working on the ICR1.
After removing the antenna wire link from the back of the BNC antenna connector, undo the four
screws holding the mainboard to the aluminium back case half as indicated here:
Then the mainboard can be carefully pulled out and away from the back case half. Now it's time to
attack the BNC connector: use a ring nut spanner (if you have one) or a pair of needle nose pliers to
loosen the ring nut that secures the BNC connector. Once you have the ring nut off, the BNC
connector can be pulled out. Now would be a good time to put these away in the resealable plastic
bag mentioned above too. While you have the BNC connector apart, you may wish to find a
suitable sized lock washer to go under the ring nut once you reassemble everything – this ring nut
has a habit of twisting loose after extended use and eventually causes the BNC connector to twist in
its mounting hole enough so that the little wire link fractures – and that doesn't do your reception
any good at all.
The battery retaining steel clip on the inside of the back case half can be levered off – its held on by
some very thin double sided tape only. I didn’t bother in replacing this afterward, and it doesn’t
seem to do anything useful.
Lastly, use a sharp blade to lift a corner of the silver manufacturer’s sticker on the back of the case,
so you can carefully peel it off. Now you have a bare case back half that can be safely worked on to
fix any peeling paint or scratches etc. I opted to have my case sand blasted by a local motor
mechanic workshop. After thoroughly cleaning away any grit from this process, I used an etch
primer in a spray can to give one thin even coat, and then two thin even coats of a satin-finish black
paint in a spray can, leaving 48 hours between coats to let each thoroughly dry.
Sand-blasted to bare metal chassis on left, repainted & ready for reassembly on right:
Now, while you've got the IC-R1 apart, why not have a look at some of the modifications below?
Modifications
Chameleon colours:
Difficulty: moderate.
One modification that I initially consider for many radios is a purely cosmetic one. Most
radios have a pathetic, pale green backlight for the LCD display. Green isn't the most exciting
colour choice, but it is a logical one: the peak vision response of the human eye is to the colour
green, and so use of that colour for backlighting is the most efficient. Besides, green LEDs are
cheap & plentiful. I usually prefer a blue backlight, and conversion to blue LEDs is a favourite
modification of mine. With the Icom IC-R1 apart, remove all the tiny screws holding the PCBs to
the front case half, and unsolder the two speaker connections. Then very gently lift the
microprocessor & keyboard PCBs out. To access the LCD backlight LEDs you'll have to remove
the metal frame surrounding the LCD first – it has little 'feet' that protrude through the PCB and are
slightly twisted to retain it. Then you can remove the LCD and finally get access to and replace the
backlight LEDs that sit either side of the LCD; any replacement LED needs to be rated for 10mA
forward current and around 2 volts VF. The original LEDs are an SMD SOT-23 size and rated at
10mA each for 2mCd luminous intensity output, but you can use just about any SMD LED that's
about 2mm in length, as that will solder just fine diagonally across the lands meant for a SOT-23
device.
However in the case of this Icom IC-R1, I thought that the existing green backlight was not
only adequate, but looked OK for the radio too and so decided to keep the original LED
backlighting.
Changing the RX / busy LED:
Difficulty: moderate.
The little RX/busy LED was another matter though, it is too dim and impossible to see in
daylight. Modern LED technology is fantastic, you can get a much brighter LED for the same
current draw; a brighter indicator without causing increased battery consumption is the result.
Interestingly, the Icom IC-R1 uses a bi-colour SMD SOT-23-sized LED for the RX/busy
indicator. Perhaps that's a hangover from their IC-2SAT & IC-4SAT ham transceivers (which both
look almost identical to the R1) where red would be used to indicate transmitting, and green for
receiving. It wouldn't surprise me if the IC-R1, IC-2SAT & IC-4SAT all used nearly identical logic
boards, just fitted with a different microprocessor. The original RX/busy indicator LEDs are rated
at 10mA and 2mCd (milli-candela) luminous intensity. Just like the LCD backlight LEDs, you don't
have to replace these LEDs with more SOT-23 style devices, any suitable SMD LED that is about
2mm long will do the job, as that will fit onto the PCB lands of the original SOT-23 device just fine.
I replaced my RX/busy LED with a 22mCd green LED for the same current and forward voltage,
Mouser part number 78-VLMG21J2M1. The RX / busy LED is now noticeably brighter and much
more visible in daylight use.
The end results are bright & clear:
Fix that selectivity issue:
Difficulty: advanced.
Now, things start to get a bit more serious. Let’s improve some of the woeful selectivity
problems with the IC-R1. One of the most common problems is with 'images' (technically, they’re
not really images, but the effect is similar) caused by the spurious response of the 3rd IF ceramic
filter. All ceramic filters have this characteristic and normally clever receiver design manages to
overcome the issue so it never becomes a problem for the listener. However, the real estate within
the IC-R1 is at such a premium that shortcuts had to be made. If you come across a fairly strong
signal, the poor spurious response of the 3rd IF filter means you’ll begin to hear that strong signal on
just about every frequency from 250 kHz below to 250 kHz above the real frequency, with the worst
appearing 190 kHz away. Now, if we were to filter the IF more tightly in the 2nd IF stage, before it
gets to the 3rd IF 455kHz stage, the spurious response of the little 3rd IF ceramic filter (a
CFUM455E filter if you're interested) wouldn't be so much of a problem. Icom left this 2nd IF filter
stage quite wide open to make it useful for WFM which needs a wider bandwidth – they use a near
300kHz wide SFE10.7MS2G 2nd IF filter. If we were to replace this with a much more narrow filter
of about 80 kHz width, any signal that starts to fall within the spurious response area of the 3rd IF
crystal filter is eliminated before it even gets there by this more narrow 2nd IF filter. This will have
an unintended consequence though: WFM signals do become slightly distorted passing through this
more narrow 2nd IF filter. I think that's an acceptable trade off, and it does genuinely lift the
performance of the receiver in general. I’ve found that it also improves sensitivity slightly (by
about 2dB) as well. If your head is spinning after all that techno-babble, the take home message is
this: replacing the original 2nd IF filter with a more narrow SFE10.7MTE filter will improve the
overall reception of the IC-R1, at the expense of slightly distorting WFM signals.
Be warned this mod is not for the faint of heart. It will involve complete disassembly of the
R1, it'll involve de-soldering tiny components, and you will need to be a skilled operator with a
small soldering iron.
With the main board removed from the aluminium back case half after having de-soldered
the antenna connection first, carefully lay the innards of the IC-R1 on an anti-static mat and desolder the ceramic filter off the main board. The pictures below show where this is located:
De-solder the two end pins first. Go easy, don't apply too much heat, and use a small de-soldering
braid or wick to remove as much solder from these two end pins as you can. If not quite all of the
solder comes out you may be able to use a very fine flat blade screw driver to wriggle these pins
free from the side of the PCB hole. More de-soldering, a bit more wiggling, some more desoldering and more wiggling will eventually see the end two pins of the ceramic filter free. Then
it's time to work on the centre pin. Since this is the earth pin, it'll have more PCB track to heat up in
the de-soldering process, which in turn makes it a bit harder to get all the solder out. My solution
was to heat up the centre pin & PCB land, then using a very fine flat blade screw driver, push on the
pin while the solder was molten. If all goes to plan, the ceramic filter will now fall away from the
PCB and you can then very easily remove any solder from the centre hole using your de-soldering
braid or wick.
Installing the new filter is going to be fiddly too, since there are other PCBs sitting vertically
around it on the top side of the main board. First cut the pins to be exactly the same length as the
pins of the old filter you've just removed. I used a tiny bit of blu-tac on the end of a tiny flat blade
screw driver to help position the new filter into the right spot. Once you get it in to the holes, use
another piece of blu-tac or a tiny wedge of foam to hold the filter in place to prevent it from falling
out of the PCB holes when you turn it upside down for soldering. Then, with a piece of fine solder,
solder in the pins, and breathe a sigh of relief. Don't forget to remove the blu-tac or small wedge of
foam that you used to hold in the filter for soldering. Now if all this sounds a bit too fiddly, and
you’re considering removing a nearby vertical board to give you some more room to access and
remove the ceramic filter, here’s a big tip: DON’T. Desoldering those vertical boards is next to
impossible, and you’ll likely end up causing more harm than good in doing so.
After all that fiddling around, the end result is very worthwhile: far fewer 'images' (or more
accurately: spurious response signals) close by to the real frequency. Sensitivity is improved
slightly. Wide-FM signals do suffer a tiny bit of distortion from this narrower filter but is really
only just noticeable on certain broadcasts eg: rock / pop music. With news / talk WFM signals
you'd never know any difference. If you are looking to do just one modification to your Icom ICR1, then this is the one to do. If you are wondering where you can find these filters, I have some
SFE10.7MTE filters for sale at AUD $10 each (postage is extra, at cost), email me at:
[email protected] for more details - remove the NOSPAM from the email of course.
Even more selectivity?
Difficulty: advanced.
As standard, the Icom IC-R1 is fitted with a CFUM455E ceramic filter which determines the
bandwidth for reception in AM & FM modes. This filter is a good 15 kHz wide, which gives
excellent fidelity of received signals, but isn't especially selective when you are dealing with two
adjacent narrowband (e.g. 10 kHz wide) signals that's far more commonplace in 2013. If you're
using the IC-R1 in an area where there are lots of narrowband signals, you can definitely improve
the selectivity by changing to a different filter. CFUM455G filters – or their modern day
equivalents such as CFULB455KG or LTM455GU models with their 9 kHz wide response curves
would be more appropriate. As always, there's a trade-off: the more narrow a filter you use, the less
hi-fi the resulting audio sounds. A filter with a 'G' bandwidth designator does tend to sound a bit
muffled or muddy compared to the wider 'E' bandwidth filters and can even introduce a slight bit of
clipping distortion on the older 16 kHz bandwidth FM signals when receiving them. If you wanted
to improve selectivity just a little bit, but retain a good degree of audio fidelity or you still have
wideband signals that you regularly listen to in your area, then a good compromise filter would be
the CFUM455F / CFULB455KF / LTM455FU series of filters. If the majority of your listening
happens to be of narrowband FM and AM signals, then the CFUM455G / CFULB455KG /
LTM455GU filters would be your best choice, and for most situations this is what I’d recommend.
Now, if you're enthused enough to change your 455 kHz ceramic filter, be prepared, it's not an easy
mod. Removing the entire DET-A board on which the 3rd IF ceramic filter is located is nearly
impossible, and I found it safer & easier to complete the job by leaving the DET-A board in situ.
You’ll need to have a pencil thin soldering iron, and be very skilled in using it. Desolder the
existing filter as shown here (the filter legs will be obvious; they’re the only four ‘through the hole’
component legs arranged in roughly a square – just make sure you don’t desolder the two resonator
legs):
After desoldering the filter legs, gently lever out the CFUM455E filter from the ‘top’ of the DET-A
board. If you don’t have quite enough room to remove the filter, the DET-A board and the other
board opposite it can be very gently bent backward to give you some more room to pull out the
filter – but be very, very gentle doing this! Once the filter is out, hopefully this is what you’ll see:
Fitting the new filter and soldering it in place is a little tricky – cut the new filter legs to the same
length as the filter you just removed, and carefully manoeuvre it into place, and solder it in with the
minimum amount of solder possible. Once your new filter is in place, the end result is improved
selectivity, which will be especially useful in crowded VHF & UHF bands with narrowband signals.
Sensitivity is also slightly improved as well. Is it worth the trouble? I think so. Combined with the
other filter change above, this transforms the Icom IC-R1 from a rather interference prone radio into
one that is most definitely usable. This is how Icom should have delivered the IC-R1 back in 1989.
Unfortunately neither modification will help with the intermod problems the R1 has e.g. FM
broadcast signals mixing to produce weird products of their signals all over the bands. But trust me,
these two filter changes together really do make a fantastic difference.
Tame the AM:
Difficulty: advanced.
If you like to scan a mix of FM and AM airband signals, you’ll notice that AM transmissions
are received somewhat louder than the FM signals, which can be quite annoying. This problem is
even worse with narrowband (10kHz) FM signals; with a lower deviation these narrowband FM
signals do tend to be even lower in volume by comparison. The fix to even out the received volume
between AM & FM is easy: change one resistor. Only problem is, it’s on that pesky DET-A board,
and isn’t easy to access. As usual, it’s easier to leave the DET-A board in place, and change the
resistor in situ. Change the indicated SMD resistor to a 47k (473) value:
A more funky Function:
Difficulty: moderate to easy.
Another mod that can be performed is to change the action of the 'Function' button on the
side of the R1. Normally, you need to press and hold the Func button while pressing another to
invoke an operation. This can be changed so that you only need to momentarily press the Func
button and then you will have about five seconds to press the secondary button for the function you
want. This will make the IC-R1 easier to operate with one hand, however there is a trade-off (isn't
there always?) When using the Func button & VFO dial together to rapidly tune through
frequencies, the rapid stepping is only active for as long as Func is held in. In its factory
configuration, that's as long as you hold your finger or thumb on the Func button; with this mod that
will now be for however long you have your finger or thumb on the Func button plus a fixed five
seconds after that. If you still want to do this mod, here's how it is done: find a 4.7uF SMD chip
capacitor and a 1k-ohm SMD chip resistor. Solder the negative of the capacitor to any convenient
ground point, and solder the 1k-ohm resistor to the positive side of the capacitor. Then solder a fine
wire to the free end of the resistor, and the other end of the wire goes to the contacts of the Func
button. The below picture shows how this is done.
Expanding your mind:
Difficulty: impossible.
What about other mods? Could the measly 100 memory channels be improved upon?
Sorry, that isn't possible. The memory that holds all your frequencies is stored inside the on-board
RAM of the microprocessor, and you have to live with what the manufacturer Hitachi gave it (1184
x 4 bits in case you were interested)
Expanding the frequencies:
Difficulty: super advanced.
OK then, what about increasing the frequency range? Going below 0.1 MHz wouldn't be a
good idea, the R1 is already a very poor performer in that area, though in theory it has the hardware
to go all the way down to 0.005 MHz. Likewise, the R1 could theoretically go up to 1334 MHz as
its upper limit – but all this is hard coded into the HD404808H microprocessor. A very interesting
feature of the HD404808 is that you can, with some external jumpers soldered into place, put the
microprocessor into a 'developer' mode and read out, byte by byte, the code that has been 'blown'
into it. After extracting this code, you could reverse-compile it into something readable by human –
it's very close to Assembly low level programming code – and then modify that code to accept
frequencies the IC-R1 only ever dreamed about. If you were extremely motivated, you could even
completely re-write the code to completely change the way the IC-R1 does things. Hitachi had
available a code simulator to test your new code on a PC first, and once happy with that you can
then 'blow' your new code onto a brand new HD404808 and fit your new microprocessor in to the
R1.
International flavours of the IC-R1.
Difficulty: moderate to easy.
It isn't hard to unlock some frequency ranges blocked for delivery to certain countries. For
example, IC-R1 units destined for France will not tune the 87.5-108 MHz FM broadcast band while
those going to what was West Germany could only tune the amateur ham bands of 13.95-14.5, 28.029.7, 144.0-146.0, 430-440 and 1240-1300 MHz.
It appears as if Icom had marked the logic board with a small black dot sticker with a
version number on it, which indicates what configuration the R1 has been set up to:
#01 - Unknown, but seems the same as #05, #07 and #08
#02 - West Germany (FRG)
#03 - France (FRA)
#05 - USA (USA)
#07 - Australia (AUS)
#08 - Asia (SEA)
Whatever version you do have, to restore full coverage 0.1 to 1300 MHz, remove D9 if
present and if D10 isn’t already a DA115 (marked with an “AU” on its top), replace D10 with a
DA115 SMD SOT-23 style diode, or if you can't get that particular diode pack then any SMD
general purpose diode will do, as per the picture below.
There are two exceptions to this:
• In Japan, the home of Icom and birthplace of the IC-R1, coverage of Japanese domestic
market IC-R1s were restricted to 0.1-252.9, 255.1-261.9, 266.1-270.9, 275.1-379.9, 382.1-411.9,
415.1-809.9, 834.1-859.9, 889.1-914.9 and 960.1-1300 MHz, the gaps being various cordless &
mobile telephone bands in Japan.
• For the USA, some IC-R1s had their entire 800 MHz band blocked. More on this below.
Both these models had the blocked bands hard-coded into the microprocessor, not dependant
on the diode configuration at all. This means that you can't unblock the blocked frequencies by
changing the diodes in any way.
Activating the hidden 'auto' mode.
Difficulty: easy.
Hidden inside the Icom IC-R1 is a mode that will let the receiver automatically select the
reception mode and frequency step based on the displayed frequency. This is very easy to activate simply remove D9 (if fitted) and remove D10. That's all there is to it! Once done, the IC-R1 will
automatically select the following:
0.1 to 1.629 MHz
AM, 9kHz
1.629 to 29.000 MHz
AM, 5kHz
29.000 to 76.000 MHz
FM, 5kHz
76.000 to 108.000 MHz
WFM, 50kHz
108.000 to 137.000 MHz
AM, 25kHz
137.000 to 170.000 MHz
FM, 5kHz
170.000 to 225.000 MHz
WFM, 50kHz
225.000 to 470.000 MHz
FM, 5kHz
470.000 to 770.000 MHz
WFM, 50kHz
770.000 to 1000.000 MHz FM, 12.5kHz
1000.000 to 1300.000 MHz FM, 10kHz
You can over-ride these selections manually, and the nifty thing that happens when you do,
is the IC-R1 'remembers' that selection, and makes it the new 'auto' selection for you. So, if you
happened to want to tune the 137 to 170 MHz portion in AM with 8kHz steps, every time you
dialled up a frequency in that band, it would default to AM with 8kHz steps! Unfortunately, the
band frequency limits that these apply to can't be changed, only the frequency step and mode. As a
bonus, if you happened to have either the West German (FRG) #02 or French (FRA) #03 variants of
the IC-R1, the blocked bands of those two types would be undone, and give you full 100 kHz to
1300 MHz coverage.
Restoring 800 MHz?
Difficulty: super advanced.
Icom delivered some IC-R1s in the USA with the silly 800 MHz cellphone block. Icom
implemented this in a very broad-brush manner, prohibiting stateside destined IC-R1s from tuning
anywhere in between 800 & 900 MHz which also restricts tuning in to any of the two way and other
interesting radio services that live in this area too. It appears as if Icom USA modified the code
written into the HD404808 microprocessor, to prevent the input of any frequency at 800 MHz. To
remedy this situation, you'd need to read out the code in developer mode, find the bit of code that
inhibits 800 MHz reception, rewrite that code, and burn it to a new HD404808 and fit that to the ICR1. Unless you were really attached to your IC-R1, it's probably not worth the effort. Of interest,
the image issue noted above, permits you to hear at least some of the blocked 800 MHz band by
tuning 21.4 MHz above the wanted (blocked) frequency. For example, if you had a requirement to
tune in 885.000 MHz, simply dial up 906.4 MHz and you'll be able to hear a slightly weaker 'image'
of 885.000 MHz. I wonder if Icom purposely left the images in for this reason....? Even so, this
technique is only good for listening to frequencies down to 878.600 MHz, so it's not a complete
solution to the missing/blocked band.
Other weird and wacky diode configurations.
As seen above, D9 and D10 are used to set various country specific restrictions, in particular
West German and French versions of the IC-R1. But that leaves a lot of unlisted combinations of
those diodes - most of the unlisted combinations don't do anything, but there's a few that do some
interesting, if somewhat useless, things:
This diode configuration of D9 and D10 will give you full unblocked coverage, no auto mode, but a
curious thing happens when you tune above 1300 MHz; the display shows "15__._0". I had a play
but couldn't get the R1 to do anything interesting in this state. If you know what this is supposed to
do, I'd love to hear from you.
This diode combination is particularly useless. It will permit reception of 13.950 to 14.500 MHz
only.
Make me faster:
Difficulty: moderate.
Another mod that I like to experiment with is increasing the scan speed of the radio.
Sometimes you can improve how quick a scanner scans by careful arrangement of your frequencies,
typically having the memories arranged so that the stored frequencies are in ascending order so the
circuitry doesn't have to constantly change from VHF to UHF to VHF to UHF frequencies as it
scans. But if that doesn't yield enough improvement, there are things you can tinker with inside the
radio that can help boost your scan speeds. This can be done by upping the frequency of the
microprocessor clock – effectively overclocking for a scanner! I've managed to achieve a reliable
40% faster scan speed on many elderly Tandy / Radio Shack scanners, and this is possible on many
other scanners too. The Icom IC-R1? I'm not so sure. You see, there's a lot of commonality
between the Icom IC-R1 and it's amateur cousins the IC-2SAT & IC-4SAT. One difference is of
course the microprocessor fitted. The other difference is the clock speed at which the
microprocessors are run at. The ham radio units are fitted with slower microprocessors and are
clocked at 798kHz. The Icom R1 micro is clocked at roughly 4.2 MHz, more than five times faster.
That tells me that Icom have purposely used a faster processor for the R1 because of the nature of
what it is being asked to do: constantly scanning through frequencies means doing a lot of fast
talking to PLL circuits. The HD404808 micro is specified to run a clock of 4.0 MHz, so as you can
see Icom are already slightly overclocking this micro already. I doubt it would take much more
before you get random crashes. But if you want to experiment, a 5 or 6 MHz crystal in one of those
tiny tube type cases would be a good starting point. Just make sure you change the right crystal on
the microprocessor board, you’ll be interested in the crystal that sits between the processor and the
flexible tracks. The other crystal sitting between the microprocessor and the CL2020/VL2020 coin
battery is the 32.768kHz time-of-day clock crystal.
The smallest SSB wideband scanner in the world?
Difficulty: advanced.
When Icom unleashed the IC-R1, they really raised the bar as to what a scanner could do.
The IC-R1 was the first handheld scanner that sported an S-meter, a RX indicator LED, it could
cover more frequencies than any other handheld before it and it was the smallest scanner to ever hit
the market up to that time. With so many 'firsts' in this innovative little scanner, many people asked
why Icom couldn't have pushed the boundaries that little bit further, by creating the first handheld
scanner to have SSB reception? It certainly would have been a remarkable achievement back in
1989. (For reference, the first handheld scanner on the market with SSB was AOR's AR1500,
released around 1992.) Ever since then, occasional rumours surfaced of the existence of a
modification to add SSB to the diminutive Icom, but little substance was ever provided.
So, can SSB be added to the IC-R1? Most definitely, yes! However, be aware that SSB
reception is going to be a bit of a compromise; the IC-R1 isn't all that fantastic on HF to begin with
due to all the noise, birdies, spurious mixing products etc. It's IF strip was never designed with SSB
reception in mind, and the standard filters as fitted are too wide for serious SSB reception. All that
said, it does work and under ideal conditions works very well indeed. Given a short telescopic
whip, the IC-R1 is more sensitive and will pick up weaker SSB signals than an AR8000! If you put
a bigger antenna or other very strong signals into the equation, the IC-R1 does begin to suffer quite
substantially, though. After completing this modification, the end result is that you will be holding
the smallest SSB capable wideband scanner in the world.
You can find a short YouTube demonstration of the IC-R1 receiving SSB here:
http://youtu.be/kWPn_etN5v8
Generally speaking, there are two methods you can use to give your R1 SSB reception:
The external BFO method: Notice the line out socket on the top panel? This happens to be a
stereo three-contact 2.5mm audio socket, of which only two contacts are used, leaving one free
contact for you to use as you wish. The 'tip' is used for the line out signal, the 'sleeve' for ground,
leaving the 'ring' available to be converted to an input socket for an external BFO, to inject a
455kHz beat frequency into the 3rd IF stage on the 'Det-A' board, at the TK10487M detector IC pin
6. Note here that we are describing a fixed 455kHz BFO signal to be injected into the IF stage, not
a BFO signal that is almost the same RF frequency being received. A convenient point to inject this
external BFO signal is on the top leg of the tiny S-meter adjustment pot 'R5'. First of all, you'll
need to remove the main RF board from the metal chassis, which means desoldering the antenna
connection and I would advise removal of the three wire jumpers that connect to the
volume/squelch controls PCB. Once you have the main board free, you'll find a small 'daughter'
board at the very top of the main board, this is the REG unit. You'll have to at least partly remove
this board as the components on it get in the way of making a connection to the solder contact point
for the line out 'ring' connection solder land. Once that is done, solder a very fine wire from the
solder land of this 'ring' contact, going to the S-meter pot as indicated in the diagrams below.
Another view of the Line Out connector 'ring' PCB land. Note the REG PCB has been removed for
clarity - it has to be removed to solder to this land anyway.
It's important that you capacitively couple the BFO signal into the IC-R1 – use a small 100pF
capacitor on the output of your external BFO to prevent any DC from upsetting the circuitry of the
Icom. The BFO injection level is fairly critical, and ideally you would want to adjust the BFO
injection level to suit the signal level being received. Stronger signal received needs a stronger
BFO injection level, and with an external BFO this is a dead easy thing to do, if it has a variable
output adjustment. Too strong a BFO injection level and you'll overpower any incoming signal, too
weak a BFO injection level and the signal will overpower your beat and will have only minimal
effect. A good starting point compromise level for BFO injection registers as an S-meter reading of
about half scale with no other signal input, in AM mode. Make sure you've adjusted the S-meter R5
pot to an S9 reading at -93dBm / 5 microvolts, not the -117dBm specified in the Icom service
manual. Reassemble the radio, and all that's left to do is select AM mode, find & tune in a SSB
signal in 0.5kHz steps, and if you have the ability to adjust the external BFO level, carefully adjust
for best reception. If you can tune the frequency of your BFO slightly, that will act as a fine tune
for your SSB reception.
The completely internal, no holes installation method: if you are skilled in super miniature
SMD construction, you can build this tiny 455 kHz ceramic oscillator circuit and fit it into one of
the tiny spare spaces available in the R1. Doing this sort of modification is about as bonkers as
cramming a V12 engine into a Mini, but if you can do it, why not? Turning on/off SSB is achieved
by making use of the line output socket as described above, only this time we're using the socket as
a method to switch on the internal BFO circuit. Only three wires are involved: the circuit
conveniently receives its 5 volt switched power from pin 2 at the top of the I/O expander unit, BFO
output is soldered to S-meter pot 'R5' as above, and the circuit earth is taken to the solder point for
the line out 'ring' contact. All that's needed to activate the BFO circuit to receive SSB, is to place a
'shorting plug' – a mono 2.5mm audio plug does the trick perfectly – into the line out socket. That
will cause the 'ring' contact to be connected to the earthed 'sleeve' contact, and hence the BFO
circuit is supplied with an earth and begins to oscillate.
Mini BFO schematic
The built circuit, using SMD components as far as possible. Note the standard ¼ watt 10M ohm
resistor – SMD resistors of this value are difficult to obtain. The size of this standard resistor
should give you an idea of how small the circuit needs to be.
The values of the resistors & capacitors in the BFO circuit have been chosen to give good reception
for weak to moderately strong SSB signals; strong SSB signals will distort just a little. If you
regularly receive very strong SSB signals, the 220k ohm resistor could be reduced a little, to 180k
ohm. Once you've built the circuit, enclose it in electrical tape or heatshrink, place the circuit into
whatever convenient spare space you have available in the IC-R1 – I chose placing it in the gap to
the bottom right of the main board, next to the PLL shielded section - and neatly form the three
wires, and solder them to the appropriate attachment points.
Just three wires to hook up. The BFO circuit is the little blue square in the bottom left of picture,
with three red wires connecting to the IC-R1's circuitry: BFO output to the top of R5 pot, power
supply to pin 2 of the top of the I/O unit, and BFO earth to the Line Out socket 'ring' solder land,
hidden from view in this picture.
As above, you should also take this opportunity to correctly adjust the S-meter pot 'R5' to give an
S9 reading at -93dBm / 5 microvolts. Reassemble the IC-R1, and you're ready to receive SSB. To
test that the BFO circuit is working properly, tune in to a vacant VHF frequency in NFM mode, and
plug in a 2.5mm mono audio plug into the line out socket. This will turn on the BFO, and if all
goes well, you should hear a weak S2 or thereabouts carrier in NFM mode. Switch to AM mode,
and the BFO should register as a mid scale S5 dead carrier. The real test is when you tune in to a
SSB signal on HF. Given that you have no BFO 'fine tune' adjustment, you're relying on the Icom's
0.5kHz steps to tune the SSB signal in for best clarity. While that isn't a fine enough tuning step for
perfectly zeroing in on every SSB signal, it gets you close enough 95% of the time. I found that the
BFO circuit oscillated at 456kHz, and as a result my IC-R1 typically has to be set with the
displayed tuned frequency to 2.5kHz higher than the actual frequency to be received in SSB.
Would the real discriminator tap please stand up:
Difficulty: advanced
Traditionally, discriminator taps are made on the NFM receiver IC's discriminator output
pin, and for the IC-R1, that would mean making a connection onto pin 11 of the TK10487M SMD
IC, which is located on the good ‘ol Det-A board. However, as previously indicated, these boards
are impossible to desolder safely, and pin 11 is very close to the bottom of the Det-A board, making
it impossible to access while in-situ. Therefore, I don’t recommend attempting tapping the
discriminator in this particular way.
There are some instructions on the internet that indicate a potential tap point on the 3rd pin of
the Det-A board where it attaches to the main board. The problem with this tap point is that it is
after the de-emphasis network R7, C24 & C25 on the Det-A board, and so this isn't a true
discriminator tap. The author indicates that he has used this tap point to successfully decode control
channel streams in trunker programs, however I am guessing those would only be lower bit rate
control channel types. Anything involving 9600bps signals or 4 level FSK signals are likely to not
be happy with the signal from that tap point.
I've found an accessible point on the Det-A board that you can obtain a true discriminator
output from, and it works an absolute treat. This can be found on the junction of R7, R9, C11 and
C12. You will have to be hyper accurate with your soldering with a very small soldering iron, and it
is easiest to attach onto R7. This is easiest done by making a 'fish hook' shape out of the fine wire
to solder to the tap point, and holding the wire onto the solder pad of R7 while heating it with your
very fine tipped ultra-small soldering iron:
Discriminator tap point on the Det-A board.
Discriminator waveform of a 9600bps digital transmission - perfect!
The resulting discriminator tap has an exceptionally clean signal at about 1 volt peak to
peak, which will nicely drive most slicer circuits, or a PC line-in input. Interestingly, all my other
scanner discriminator taps require the data to be inverted, but with the Icom IC-R1 discriminator tap
the data doesn't need to be inverted. If you find the discriminator tap isn't working for you, try
inverting (or not) the data in your software, if it offers that ability. Some software applications will
do this automatically.
A convenient way to then bring the tap point to the outside world is to sacrifice the line out
signal, and connect the discriminator tap to the 'tip' of the line out socket. Lets face it, who uses the
line out facility of the R1 anyway? I opted to use the 47k ohm resistor that was already present in
line with the line out signal, by very carefully cutting the track just before the 47k ohm SMD
resistor, and then soldering the discriminator tap to that resistor. Having this 47k ohm resistance in
line with the discriminator tap helps give some isolation between the receiver and whatever you are
connecting it to. Getting access to this resistor for the tip connection of the line out socket requires
removal of the REG unit, a small vertical PCB at the top of the main PCB.
Line out 'tip' PCB connection point - perfect for a discriminator output.
Note the REG PCB has been removed for clarity in this picture.
How charged is my internal battery?
Difficulty: dead easy!
Ever wondered how well charged your internal battery is on the IC-R1? Would you like to
be able to check the charge state of the battery without having to open up the case of the radio?
This is the easiest modification you'll ever have to do, because there's nothing to do! An interesting
little facility that Icom built in to the IC-R1 is the ability to measure the voltage of the internal
battery pack without having to open up the radio to measure it directly. The battery voltage is
connected to the antenna connector (via a diode & 10k ohm resistor) so you can measure a DC
voltage at the BNC antenna connector. All you have to do is remove the charger from the Icom ICR1, remove the antenna and measure the DC voltage across the BNC connector; the IC-R1 doesn't
even have to be turned on. You should see a voltage which is about 0.2 volts lower than the actual
battery pack voltage. A voltage above 7.0 volts is OK and should be able to properly power up the
IC-R1. A voltage below 7 volts means the battery is flat, and it needs further charging. If the
battery won't charge above 6 volts then it means a new battery pack is required. A healthy fully
charged battery pack will read between 7.8 and 8.8 volts. If you're worried about this voltage being
on the antenna connector, don't be - because it's being isolated by the 10k ohm resistor and diode, it
won't hurt anything at all.
Fill ‘er up fast:
Difficulty: moderate.
Being nearly 25 years old, it’s a fair bet that most Icom IC-R1s will be in need of a new
internal battery pack. These can be replaced quite easily, and can be found on eBay at very good
prices; I paid only $14 for one which included delivery to my door. As a bonus, the new pack has a
capacity of 600mA/h which is double the capacity of the original, and there are some that are rated
as high as 750 mA/h. This is great, since it gives you a longer operating time between charges. The
only downside is that where the original 300mA/h pack took 16 hours to charge, a 600mA/h pack
will take 32+ hours to fully charge, and even longer for the 750mA/h packs. Fear not, there is a
way to increase the charge rate for your higher capacity batteries, so you only have to charge them
for the usual 16 hours or thereabouts. Change the three indicated resistors below as shown. These
live on the circuit board that sits at the very bottom of the IC-R1, with the extension battery pack
contacts on it. Once done, you’ll need about 16 hours for a 600mA/h pack or 20 hours to charge a
750mA/h pack. You could lower the 22k resistor down to even less than 10k – I’d suggest 8.2k but
no lower – to set the charge rate a bit higher, but then you run the risk of stressing the existing
components beyond their comfort zones.
Lots left in the tank:
Difficulty: moderate.
So you need a new battery pack? 600mA/h or 750mA/h not enough for you? How about a
whopping 1800mA/h - now you're talking... err, listening. You can't buy ready made battery packs
of that capacity, but you can build your own, and it isn't all that hard. You'll want to find so called
2/3AA size rechargeable batteries, with a size of about 28mm height and 14mm diameter.
Deconstruct the original battery pack to see how the cells were originally arranged, and to recover
the little flying lead & connector which you'll use for the new battery pack. Solder six of the new
cells together in series to form a 7.2 volt pack, and then get some 64mm PVC battery shrink wrap to
hold the cells together into a pack. Don't use normal heatshrink, this stuff is too thick and you won't
be able to fit the new battery pack into the R1. The highest capacity in this unusual 2/3AA size is,
at the time of writing, 1800mA/h which should give around 18 hours of average use. That's six
times more run time than what the original 300mA/h battery pack offered. The only problem with
this is that to charge a 1800mA/h battery pack from flat to full, even with the faster charge rate
modification above, would need 48 hours. You might want to find a BA-12 charge adapter & BC72 drop in rapid charger if you don't want to wait that long.
Shields up:
Difficulty: moderate to easy.
Even though the Icom IC-R1 has a diecast back case half, the front case half is still plastic,
and there's very little other internal shielding. Borrowing an idea from the IC-2SAT, where Icom
have fitted a metal shield over the RF sections, shielding those sections from microprocessor and
logic noise; in a similar way we can add a shield to the IC-R1. You can use thin copper plate or tin
plated steel and cut it to shape as shown in the picture below - it doesn't have to be exactly the
same. Make sure that the new shield doesn't short out anything on the RF board, or the logic board
when everything is reassembled. This can be done by a layer of wide electrical tape on each side of
the new shield, except where the shield is to be soldered to attachment points of course, or a good
coating of a heavy paint can also achieve this.
Amateur HT cousin IC-2SAT internals.
Note the shield over the RF section - a similar shield can be made and fitted to the IC-R1.
Even more shielding can be added in the form of a thin coating of conductive nickel spray
paint to the inside of the front plastic case half. Taping up any exposed surfaces of the case you
don't want to get any nickel spray on is a very tedious task, but is an absolutely vital step. Don't
forget to tape over the inside of the display lens and the little opaque plastic 'light pipe' that forms
the RX busy indicator on the front top panel. Once you are all done with the masking tape, apply a
very light coating of nickel spray; the tolerances of the IC-R1 internals are so fine that if you apply
too much nickel spray in a coating that is too thick, this might prevent proper reassembly of the
receiver.
The benefit of these two modifications together reduces birdie count by 21 % and makes the
birdies that remain slightly weaker, but biggest benefit is that the receiver is 'cleaner' overall, with
less noise behind some weak signals, especially at VHF and above.
Sounds good to me:
Difficulty: easy.
Another modification that aims to slightly improve the sound quality of the tiny speaker of
the IC-R1 is deceptively simple. By covering the back openings of the speaker with some common
sticky tape, you can make the speaker sound slightly less tinny, but at the expense of volume – this
will reduce the speaker efficiency by about 25%. This will be a personal taste thing; I found the
sound quality improvement minimal and the loss of volume to be an unacceptable trade-off.
What the…?
There is one modification that I’ve seen done to an IC-R1 that mystifies me. This mod
consists of a common 1N914 or 1N4148 diode and 2.2k resistor that connects between the logic
Vcc line and ground. How it works… I don’t know. What it does or is supposed to do… I don’t
know. The only effect I could observe was that the decimal point of the LCD display disappeared.
If anyone has any clue as to what this modification was trying to achieve, I’d be really pleased to
hear from you.
Things the IC-R1 can't do:
After looking through this list of mods for the Icom IC-R1, you could be forgiven for
thinking 'is there anything this scanner can't do?' Well, yes, there are features you can't add just by
modifying the IC-R1 - they would either be just too complex, impractical or expensive to do, or the
basic design of the scanner just wouldn't support it:
 Trunk tracking or digital receive modes. This is something that has to be integrated into
the design of the receiver from day one.
 Computer control / memory upload & download. While you could alter the HD40408's
RAM contents (where memories for channels are stored) by reading & writing via
instructions from a PC, this would require modification to the program running in the
HD40408 PROM and some additional circuitry as well. It's unlikely the HD40408 has
enough spare memory for these external RAM programming routines. (side note: there
are 'PC interface cables' listed on eBay that are supposedly compatible with the Icom ICR1. Don't wast your money, the IC-R1 definitely does not have the ability to be PC
controlled or programmed.)
 CTCSS. There just isn't enough room inside to add circuitry for this, and no practical
way to control this facility from the keyboard.
 Alpha-numeric display: the HD40408 microprocessor just isn't powerful enough to
support a new fancy alpha-numeric display. Besides, even if you could get an alphanumeric LCD display that small, how would you be able to read it?
2GHz modification?
Increase the frequency coverage to 2 GHz! Um, no.
Don't believe everything you see. The above photo is real, and hasn't been doctored in any
way. Yes, the display is reading 1999.975 MHz and appears to be receiving a signal. But it's a
trick, the IC-R1 isn't really tuned to or receiving that frequency - you can enter any frequency up to
2 GHz but not push enter - and this is what the display will show. Once you hit the enter button, the
IC-R1 will emit an error beep and go back to the last frequency it was tuned to.
Discussion of images on the IC-R1:
Some of the above modifications replacing the 2nd & 3rd IF filters make a dramatic
improvement to close-in selectivity, but do nothing to fix the genuine image issues of the IC-R1. To
demonstrate this issue, dial up any strong VHF or UHF signal lower than 534.2 MHz. Then tune
21.4 MHz below your tuned frequency, and you'll find the same signal - an image of the real one,
only slightly weaker. You'll find that the images will fall 21.4 MHz above the real frequency for
those signals above 534.2 MHz where the IC-R1 switches from high to low side local oscillator
injection.
In the IC-R1, the wanted incoming RF signal is amplified, then mixed with a local oscillator
to convert the wanted received signal down to the 1st IF frequency of 266.7 MHz. This 266.7 MHz
IF signal then passes through a filter, and proceeds on to the 2nd IF stage, where it is mixed with a
fixed 256 MHz local oscillator to convert that to the 2nd IF of 10.7 MHz and then on to the 3rd IF
stage.
Mathematically, the 1st to 2nd IF conversion process goes like this: 266.7 (1st IF) - 256.0
(2nd fixed local oscillator) = 10.7 MHz, the 2nd IF. However notice that 256.0 - 245.3 also equals
10.7. What that means is that any signals sneaking through the 1st IF stage at 245.3 MHz (after
mixing with the 1st local oscillator) will also be converted to 10.7 MHz just as readily as those from
266.7 MHz. Notice how 245.3 MHz is 21.4 MHz below 266.7 MHz. Normally, those signals
trying to sneak through are blocked by the IF filter, but in this case the 266.7 MHz IF filter isn't
doing a very good job. The reason is that Icom chose to use a simple LC or inductor-capacitor filter
for this 266.7 MHz 1st IF filter. Such simple LC filters are not known for being all that selective,
and it is this lack of selectivity of this filter that causes the images to occur. Looking at a computer
model of the original Icom 1st IF filter, you can see that there's a pretty wide skirt, and that the
problem frequency of 245.3 MHz is only 26dB down. No wonder those signals that would be an
'image' manage to sneak through to the 2nd IF. In the real world, things are even worse - the image
rejection is only 15dB - an absolutely shocking result. A figure of 50 or 60dB rejection of the image
frequency would have been much better.
Original 266.7MHz LC filter response curve
I tried two methods to improving this 1st IF filter in an attempt to reduce the awful image
problems. The first option I tried was to replace the simple LC filter with something a bit more
selective. Ceramic filters are not available for 266.7 MHz, and it would be very difficult to make a
crystal filter for that frequency. Helical filters could be used, but are too large to fit. It would be
possible to use a SAW (Surface Acoustic Wave) filter: they are compact and can be made for 266
MHz quite easily, they have a pretty good 'shape' factor, and so are fairly 'selective' in this regard.
They're a high-tech option used in a lot of modern radios for exactly this purpose, indeed the ICR10 used SAW filters for the 1st IF. The good news is that a SAW filter did indeed increase the
image rejection ratio on the IC-R1 to over 60dB - a very pleasing result. The bad news is that the
SAW filter didn't match well into the IF strip and introduced about 25dB of loss and effectively
made the receiver 'deaf'. With a lot of trial and error, I'm sure this could be improved, but I didn't
persist with it.
The second option which I tried was to improve the existing LC filter by including a 245.3
MHz notch or trap. I'm quite surprised that Icom didn't implement this solution from the factory;
they did exactly that with the IC-R7100 receiver which also uses a 266.7 MHz first IF, so I wonder
why they didn't use the idea for the IC-R1 as well? Unfortunately, this idea didn't work out either,
at least not in a way that could be easily implemented by modification of the existing circuit. The
entire circuit would have to be rehashed for this method to work properly.
Available accessories for the Icom IC-R1:
Icom scanners typically have a wide variety of accessories available to enhance your user
experience with their products, and the Icom IC-R1 was no exception. Icom offered the following
optional items:
 Coming as standard with the R1 is a carry handstrap, a wideband FA-4B antenna, a
beltclip, the often lost BA-11 bottom cap that covers the battery contacts when you’re
not using an extension battery pack, a mains battery charger (model BC-74V for
Australia) and of course the user manual.
 BC-72 rapid drop in charger
 BA-12 rapid add-on charge adapter for the internal battery, used with a BC-72 above.
 LC-57 leatherette carry case
 BP-81 extension battery (30mm in height, 110mAh) – no suitable carry case for this
 BP-82 extension battery (40mm in height, 300mAh) and LC-59 carry case to suit
 BP-83 extension battery (60mm in height, 600mAh) and LC-59 carry case to suit
 BP-84 extension battery (76mm in height, 1000mAh) and LC-61 carry case to suit
 BP-85 extension battery (76mm in height, 340mAh) and LC-61 carry case to suit
 BP-90 extension battery case, fill with your own AA battery cells, along with LC-59
carry case to suit.
 CP-12 Cigarette lighter charger cord
 OPC-254 power cord for connection to a 13.8 volt power supply
 HP-4 headphones (looks like the old 1980s Walkman headphones!)
 MB-30 mounting bracket to hold your IC-R1 in the car
 AD-14 charge adapter – use the BC-74 charger to externally charge your BP81/82/83/84/85 or BP-90 if fitted with rechargeable cells.
 Even add a HM-46L speaker microphone to dress your IC-R1 up like a transceiver, and
add a convenient speaker that you can position closer to your ear while keeping the R1
on your belt!
Just a quick note on the Icom FA-4B wideband flexible antenna that Icom included as
standard with the Icom IC-R1 package: I think this antenna is actually quite good for its intended
function. It received VHF airband signals just as well as a dedicated VHF airband helical ducky
antenna, and likewise it’s reception abilities were similar on UHF to a ¼ wave whip on that band
too. An antenna analyser showed this Icom wideband antenna was resonant around 135 & 500
MHz. I did notice that the VHF highband area above 156 MHz was quite poor with the FA-4B
though. The FA-4B is made with a very soft & flexible rubber compound, which makes this
antenna quite convenient for use if you’re using the IC-R1 on your belt. Of course, the FA-4B can’t
compare to a telescopic whip for the best reception, but as a convenient portable antenna, what
Icom provided wasn’t all that bad.
Two Icom IC-R1s: on left with standard FA-4B antenna and no extension battery, on right with
optional BC-90 battery case with 6xAA batteries.
A closer look at the IC-R1’s display in action.
With Icom’s HM-46L: Is it a scanner, or is it a transceiver?
Common faults on the IC-R1
An Icom IC-R1 that won't turn on is probably a pretty common thing these days. They're
getting on to 25 years old now and chances are the majority of them have been sitting dormant in a
desk drawer somewhere, unloved and unused. The first thing to suspect will be the internal battery
is dead. Try plugging in the charger for a good 16 hours, then see what happens.
If the R1 still won't turn on, try doing a full CPU reset: turn the power off, press and hold F
(Function) and CL buttons together while turning on the radio. If all goes well, the CPU will be
reset, all memories cleared and things will be back to normal. An interesting little facility Icom
added to the IC-R1 was the ability to measure the voltage of the internal battery pack without
having to open up the radio to measure it directly. The battery voltage is connected to the antenna
connector (via a diode & 10k ohm resistor) so you can measure a DC voltage at the BNC antenna
connector. All you have to do is remove any antenna and measure the DC voltage across the BNC
connector; the IC-R1 doesn't even have to be turned on. You should see a voltage, about 0.2 volts
lower than the actual pack voltage here. A voltage above 7.0 volts is OK and should be able to
properly power up the IC-R1. A voltage between 5 and 7 volts means the battery is flat, and it
needs further charging. Anything below 5 volts probably means a new battery pack is going to be
needed. Thankfully, the internal battery pack has a little in-line connector so it can be removed with
ease. Also, attaching an external battery pack (if you happen to have one) disconnects the internal
battery pack, so that could be another option to power up the radio.
If all else has failed so far, another thing to check is the lithium cell soldered to the logic
board. If it reads any less than 2.7 volts, it's probably time to replace it with a new one - you will
have to open up the IC-R1 to read the voltage of this cell. You'll want to find a replacement,
solderable VL2020 lithium replacement cell.
A well loved IC-R1 may have a loose BNC connector from having a variety of antennas
attached & removed many times. If you find yours is loose, don’t simply just tighten the ring nut –
you should check the internal soldered connection too. If it at all looks suspect, remove as much
solder as you can and then resolder it – but don’t use too much solder! If you are likely to want to
experiment with a lot of antennae as well, then to prevent the BNC connector from coming loose
again, fit a suitably sized spring washer underneath the ring nut to help lock it in place.
If you find keys on the keypad that don’t work, you’ll need to disassemble the radio and
remove the logic board to access the keypad. Give the PCB contacts for the keyboard a clean with
some electronic grade cleaner (not flux remover!) or isopropyl alcohol. Also carefully inspect the
solder field that connects the keyboard PCB with the logic board – over time they can fracture. A
magnifying glass or similar is invaluable to inspecting & finding faulty connections like this. Be
very careful if you do need to resolder one of these connections – not only are they very close to
one another, but you can quickly make things worse with too much heat or too much applied solder.
Reassembly tips
After having fixed up all the things you wanted to and perhaps having carried out a few
modifications, it’s time to put everything back together. Here’s a few tips to make life easier for
you:
 If you’ve had the logic board away from the front panel, give the LCD glass and the inside
of the plastic lens on the front panel a good wipe over with a lint free or microfibre cloth to
remove any dust or fingerprints etc.
 Don’t over tighten the screws, especially those that hold the microprocessor/logic board and
keypad to the front panel. They’re only tiny screws, and are quite easy to strip the threads
on.
 Make sure all your soldered connections are done eg: antenna to main board & speaker to
logic board pads. There’s nothing more frustrating than having done all your mods etc. and
having then reassembled the radio only to find you’ve forgotten to solder the speaker!
 Be careful of the top panel where the volume, squelch & dial are located. You may have
discovered that it can come free from the back chassis. This is connected to the main board
with three wires. Those wires could fracture if handled roughly or bent back & forth too
much.
 Around the same top panel is a small rubber gasket. When fitting the front case (logic
board) back onto the chassis, be careful not to pinch this rubber gasket so that it bunches up.
The front panel should slide into the top panel groove snugly and without much resistance.
 When reassembling the case halves back together, make sure the Light rubber button is
seated in place over the surface mount button exactly, that the ribbon cable isn’t going to get
pinched (it’s natural lie should keep it out of the way, but best to check), that the bottom
PCB is aligned flush with the case bottom lip, that the internal battery wires are not going to
get pinched, and that the side Function button rubber gasket isn’t going to get pinched.
That’s a lot to look for as the two case halves come together, but the general idea is that if
the case halves are not going together very nicely or if you need a fair amount of pressure to
get the case halves to completely close up to one another, something is wrong – stop, check,
realign things and try again. A small flat blade screw driver can help poke wires back inside
the case as it goes together or realign rubber gasket edges as the case closes around it.
 Once together, do up all the screws in stages. Get them all only just finger tight, then go
around them all again so all screws are snug – but not too tight, its easy to strip a thread.
 Make doubly sure the screws on the underside of the IC-R1 are done up firmly, they should
be flush with the bottom. If these were to come loose in use and protrude out of their thread,
they will prevent you from removing the bottom cap or extra battery.
Icom IC-R1 serial numbers:
Each Icom IC-R1 was given a five or six digit serial number. The last four digits can be
considered to be the serial number, and the preceding one or two digits can be looked at as the
'batch' number. For example, serial numbers 0xxxx were the first batch, 1xxxx the next lot, and so
on. I have seen serial numbers as high as 10xxxx and 11xxxx. It was rumoured that later batches
had minor improvements made at the factory in an attempt to improve the rather poor adjacent
channel selectivity issues etc. but I can't confirm this. Japanese domestic market IC-R1s are easy to
identify: next to the serial number will be a triangle with the letter J inside.
Manuals on line:
Yes indeed, the user manual for the Icom IC-R1 can be found online, it’s not hard to find,
just use Google or a similar search engine to find a download location. Likewise, the IC-R1 service
manual is also available online, but be warned that there are several errors in it. The service manual
theory of operation descriptions, block diagrams, schematics & circuit board layouts are generally
OK, but don’t rely on the expected voltage readings printed on the schematics and the alignment
information is a little off or incomplete in places. I would amend the alignment procedure as
follows:
• 7-3 Receiver adjustment: Sensitivity – adjust C4 & C7 on BPF unit, and L1 on main board for
best sensitivity. The tuning of C4 & C7 is critical for best sensitivity and best image rejection, but
the tuning of L1 is pretty broad.
• 7-3 Receiver adjustment: S-meter – align for S9 reading at 500 MHz with -93dBm (5 microvolts)
input.
Also, there isn't a lot of information in the service manual regarding the 2nd Local Oscillator
running at 256 MHz. It begins with a 85.333 MHz crystal on the main board, and then goes
through a tripler circuit to produce 256 MHz.
I’ve purposely avoided listing specific URLs for these manuals, as those locations are highly likely
to change from time to time, but Google should be able to find them for you quite easily.
Other Icom IC-R1 webpages:
http://tokyoswan.web.fc2.com/10htm/ic-r1/ic-r1.htm - a Japanese webpage with lots of technical
detail, but you'll have to use a translator to read it, and then work out the resulting Jinglish!
http://hamsiam.in.th/index.php?topic=12778.0 - photos of a mint condition IC-R1
Second hand buying guide:
While the Icom IC-R1 was a fairly popular scanner back in the early 1990s, it's a fairly rare
receiver to find on the second hand market today. Interest is fairly high on eBay when they do
appear, and as always physical and working condition largely dictates the asking price, as does any
included accessories. Quite often private sellers, ham radio swap meets etc. will have cheaper
prices, versus what is being asked for on eBay. Here's a quick run down of prices you can expect to
pay in 2016:
• For a working IC-R1, it's the physical condition that largely determines the price. Excellent
condition examples complete with BA-11 bottom cap, FA-4B antenna and BC-74 charger will fetch
about $100-150, or about $75-100 for one in average condition, and even less for poor condition.
• If there are any accessories, such as carry cases, extension battery packs, drop in chargers, original
packaging & instructions etc. this can push up the asking price of an excellent condition IC-R1
package to $200 or even more.
• Missing standard accessories conversely should bring the asking price down a bit. No BC-74
charger? No real problem, any 12 volt unregulated (14 volt open circuit) power pack capable of
supplying at least 100mA with a fitting plug centre positive will do the job. No FA-4B antenna?
Again, no big problem, an amateur 'ham' dual band VHF/UHF antenna works very well with the ICR1. Missing manuals can be replaced by printing out copies found online.
• A missing BA-11 bottom cap does, in my opinion at least, quite badly impact the asking price - the
IC-R1 looks incomplete without it, and you can't stand it up on a flat surface. Without a BA-11, I'd
be bargaining down to around $50 maximum.
• If the IC-R1 you are considering buying is offered as not working and the seller doesn't know
much about the receiver and is being offered very cheap, you may be on to a good bargain. As
mentioned above, often just a reset of the receiver, a new internal battery pack or clean of the
internal contacts - all easy jobs to do - could bring the radio back to life.
• If you have a chance to try before you buy, the only things to check for are the usual suspects such
as a loose BNC connector, keypad buttons that don't work or 'bounce' (push once but get lots of
digits / beeps in response) and that the receiver is working and receiving weak signals OK.
• Neatly and well executed modifications can increase the asking price somewhat, especially since
some of the modifications detailed above can radically improve the performance of the IC-R1 above
the standard.
• A fully loaded IC-R1 package, with all the standard accessories, including original packaging &
instructions, a generous offering of other accessories such as a carry case, extension battery pack
and drop in charger, in excellent condition, and modifications done to improve performance could
well see a frenzy of interest and don't be surprised if this commands an asking price of $300 or
more.
Icom IC-R1 twin brother?
Not long after the Icom IC-R1 was released, Alinco came up with a very similar wideband
receiver, called the DJ-X1. It looked and felt familiar to the Icom. A peek at the DJ-X1 service
manual showed that it uses the same general circuit design as the Icom (the block diagrams are
almost identical), but the actual circuit of the Alinco is different to the Icom, especially in the logic /
microprocessor areas. Closely examining the circuit for the DJ-X1, it would appear as if it might
have had a slight edge over the R1 in terms of selectivity and ease of modification. The Icom was
slightly smaller, looks a lot nicer in my opinion, and had more user functions.
Comparisons with another micro-sized receiver:
I thought it might be a little bit of fun to see how gracefully the IC-R1 has aged, and put it
up for comparison against another more modern mini receiver. Thirteen years after the IC-R1 was
taking the limelight in the scanner market, Yaesu's VX-2R was having a similar impact in the micromini ham transceiver market. The VX-2R has a somewhat comparable frequency coverage
receiver, AM, FM and Wide-FM reception modes, a very generous 1000 memory channels, and by
virtue of it being half the size (by volume) of the R1, also shares that “how'd they cram everything
inside that tiny case” bewilderment upon its release to the market.
Two opponents face off in a friendly head-to-head comparison
The VX-2R doesn't have the same severe selectivity problems the R1 was plagued with, and
it doesn't have quite as noisy a receiver in the shortwave bands. Commendably, the IC-R1 has the
same basic level of sensitivity to weak signals as the VX-2R, and the Icom produces a nicer sound
output, sounding less 'tinny' than the micro-mini Yaesu. The Icom even manages to hear shortwave
broadcast stations quite a bit better than the VX-2R, given an identical antenna – so long as you’re
tuned to a HF frequency that isn't affected by one of the numerous internally generated noises or
birdies by the R1. But then, the VX-2R also has plenty of birdies below 30 MHz too. I'd call that a
narrow win to the R1 on shortwave, and a dead heat on VHF & UHF for sensitivity.
The standard IC-R1 battery is rated at 300mAh, 7.2 volts. There wouldn't be many original
R1 batteries still around these days, so let’s assume you've fitted a 600mAh, 7.2 volt pack. This
gives 4.32 watt/hours of battery capacity. Also lining up at the starting line is the Yaesu VX-2R
lithium ion battery of 1000mAh at 3.7 volts; that's 3.70 watt/hours of battery capacity. So now that
a common baseline for the battery capacity has been set, let's turn both receivers loose on a
continuously active frequency, set the volume to give the same output level, and see which one runs
out of juice first. The Icom runs out of puff after just under 4.5 hours, while the Yaesu marched on
for a total of nearly 8 hours. You could expect listening times to nearly double with average
scanning use. A clear win to the Yaesu.
So much for the current consumption efficiency stakes. What about putting them through a
beauty pageant? As it is in so many cases, beauty is in the eye of the beholder. Even so, there can
be no denying that Icom have wrought a very fine & somewhat professional looking radio with the
IC-R1. The Yaesu? It looks a little bit too much like a toy to me – perhaps the VX-2R is just too
small to be taken seriously or maybe it’s the lack of a full keypad, never the less it is a surprisingly
capable package.
How about a little singing competition? Which one can shout the loudest? If we go on
specifications alone, the Icom's 150mW wins handily over the Yaesu with its 50mW output on
battery, and it shows in real world tests too – the IC-R1 is noticeably louder than the VX-2R. Not
only that, but the Icom has a much less tinny sound – though the VX-2R does do a good job of it
considering how small it is.
If you're not excited with those results so far, then how about we look at that most manly of
competitive specifications: speed. Which one can scan the quickest? Sprinting off the blocks is the
Icom with 20 channels per second, while the younger legs of the Yaesu can't keep up at 11 channels
a second. Of course neither can compare to the steroid-fed scanners of today that rip through the
spectrum at a blistering 100-plus channels a second. But it’s still nice to see the Icom can put in a
respectable figure in this regard.
So it would seem the Icom R1 still has the goods to be a useful basic scanner even though it
is about to celebrate its 25th birthday; however it is still hopelessly outclassed in certain key areas –
not the least of which is it's selectivity issues.
Conclusions:
The Icom IC-R1 really shook up the market upon its introduction. In its time, the advanced
features & capabilities - on paper at least - combined with small size & good looks made it an
instant, if somewhat flawed, classic. They represented the very pinnacle of what was achievable in
scanners for the late 1980s / early 1990s. For this reason, the Icom IC-R1 can be considered
collectable in radio enthusiast circles, especially by those who had owned them previously. While
the IC-R1 can still keep up with modern receivers in terms of sensitivity, their lack of selectivity
and modest features by modern day standards mean that second hand prices are still reasonable. I
recently observed one in top notch condition with original packaging & accessories fetch USD $200
– expect to pay a bit under half that for one in average-to-good condition without original packaging
/ accessories. In today's context for scanners, the Icom IC-R1 isn't very relevant unless you’re using
it for the most basic of scanning duties – with no CTCSS, no trunking, no digital reception, not even
alpha-numeric channel name display its usefulness can be a bit limited by modern day standards.
But like owning an old classic Mustang coupe that guzzles fuel and doesn't have all the mod-cons –
it's just flat out cool owning one. So it is with the Icom IC-R1 in the radio world, and finding one in
pristine condition is almost impossible these days. Getting hold of a working example & restoring
such classic receivers gives a sense of satisfaction like no other - that you're preserving a little bit of
history. Thirty years later, I finally 'get' why my dad loved to restore his old cars.
Dedicated to my father, who taught me the love of repairing things. Rest in peace, dad.