Collecting and Restoring Vintage Ham Radios

Collecting and Restoring
Vintage Ham Radios
Larry Kenan KO6SM
Hallicrafters SX-28 “Super Skyrider”
Receiver (1940)
6/20/2012
KO6SM
2
Vintage = Vacuum Tubes
6/20/2012
KO6SM
3
Hallicrafters SX-28 “Super Skyrider”
Receiver
6/20/2012
KO6SM
4
Why Collect and Restore old radios?
• Preservation of Amateur Radio history
– No longer manufactured
• Nostalgia
– I can now obtain and afford all the equipment I only dreamed of
having during my high school years
• Collecting
• Investment ???
• Resell for profit ???
• Its fun doing the repairs!
– Most of the radios I have in my collection, when obtained, were
non-functional or partially-functional, in poor cosmetic condition,
or both
• It’s a “Labor of love” for the hobby!
• Preservation of Radio Skills
6/20/2012
KO6SM
5
Radioroom
6/20/2012
KO6SM
6
Vintage TV restoration
6/20/2012
KO6SM
7
KO6SM Vintage Station (2004)
6/20/2012
KO6SM
8
Vintage Manufacturers
•
•
•
•
•
•
•
•
Drake
Collins
Heathkit
Hallicrafters
National
Hammarlund
Gonset
Johnson
6/20/2012
•
•
•
•
•
•
•
Military
RME
Knight (Allied Radio)
Eico
Lafayette
Globe King (World Radio Labs)
Etc…….
KO6SM
9
Vintage Equipment to Look For
• Whatever turns you on
– I prefer 1940 to 1970 vintage
• Good equipment :
– Items which will increase in value
once they are restored
– Items which are rare
– Items which are cosmetically in good
shape even if they don’t work
• Electronics can easily be fixed
• Look for original knobs, meters,
logos, etc…
– Parts radios
• "It worked the last time I tried it" should
always be taken with a grain of salt
6/20/2012
KO6SM
Johnson Ranger
Hammarlund HQ-110
10
Johnson, National, Heathkit etc.
6/20/2012
KO6SM
11
Where to Find Vintage Radios
•
•
•
•
•
•
•
Ham Fests / Swap meets
Friends
Estate sales
http://ebay.com
http://eham.net
http://qrz.com
Other collectors
W8QYT
6/20/2012
KO6SM
12
Warnings !!!
• There are lethal high voltages inside vintage radios,
especially in transmitters
• DC voltages can exceed +800 Volts
• Before attempting any electrical repairs, make sure
you understand proper safety procedures
– Refer to ARRL handbook
• Use a AC variable power supply (Variac) when first
powering up old radios
– Vintage radios were designed for 110VAC operation. With
today’s AC home voltage near 125VAC, some older
components inside the radio may short out or explode !
6/20/2012
KO6SM
13
Important Repair Notes
Power up old radios gently. Plugging it into the wall and turning it on is
not gentle!
Check fuses before power up. Many Boatanchors will have the wrong
value fuse in it.
Don't trust that the tubes that are in the sockets are the correct tubes.
Don't clean tubes with water. The type number on the glass will likely
come off.
If you erase the dial marking on your receiver by cleaning it with Windex
or even water, you likely will not find another to replace it.
6/20/2012
KO6SM
14
Cosmetic Repairs
• Cleaning
–
–
–
–
–
–
Heathkit DX-40
Simple Green
Rubbing Alcohol
Dish soap and water
Murphy Oil Soap
Auto carburetor cleaner on chassis
For steel chassis, repaint silver
• Tools
– Tooth brush
– Dremel Tool
– Cotton swabs
6/20/2012
KO6SM
15
Cleaning Compounds
6/20/2012
KO6SM
16
Cosmetic Repairs
• Painting
– Computer match paints
– Home Depot and Lowe’s has
good color selections
• Not a perfect match,
however in most cases,
close enough
– Don’t spot paint, paint the
whole cabinet or not at all
– Wet sand with fine grit
sandpaper
– Air-Brush, if your good at
using it
• Panel Markings
– You will probably have to
spot paint
– Dry transfer & Wet transfer
Decals
– Computer graphics
recreation
6/20/2012
KO6SM
17
Hammarlund HQ-129X -- before
6/20/2012
KO6SM
18
Hammarlund HQ-129X -- after
6/20/2012
KO6SM
19
Rust…
6/20/2012
KO6SM
20
Functional Repairs
• Knobs/Meters/Trim/etc
– The closer to original, the more
the value
– Try to keep as close to original
as possible
– Acquire parts from a second
cannibalized radio
– You can find preproduction
manufactured parts
– Front panel and cabinet parts
are more critical physically
than internal components
• ie: resistors, capacitors
6/20/2012
KO6SM
21
Functional Repairs
• Oils / Lubricants
–
–
–
–
–
–
WD-40
3-in-1 Oil
DeOXit
Silicone Spray
Canned air
Light weight gear grease
Johnson Ranger with a gassy final
(not mine)
6/20/2012
KO6SM
22
The difference in repairing an older radio now
as compared to repairing it in it's early years
• When it was fairly new, you were looking for a
probable single point of failure; now there are
probably multiple points of failure
• Capacitors can fail over time whether the
radio has been used or not
• If you have just acquired a radio that hasn't
been turned on in 20 years - it probably won't
be in working order
6/20/2012
KO6SM
23
Minimum Basic Workbench
Equipment
• Manual and/or Schematic
• RF signal generator
• Volt, Ohm, Amp Meter
6/20/2012
KO6SM
24
Where can I find Manuals and Schematics?
BAMA: http://bama.edebris.com/manuals/
Lots of Vintage Ham Radio Manuals and Schematics
…except Heathkit Heathkit:
http://www.vintage-radio.info/heathkit/
http://www.mods.dk/manual.php?brand=heathkit
Receivers:
http://www.nostalgiaair.org/Resources/ (John F Rider)
Almost every receiver built in the US – up to 1954
https://www.samswebsite.com/ (Howard W Sams Co.)
Look them up online and copy them at the Phoenix
Public Library (downtown) Reference Room
6/20/2012
KO6SM
25
Workbench
6/20/2012
KO6SM
26
Another Workbench
6/20/2012
KO6SM
27
Workbench Equipment - meters
• Analog – damping
• VTVM – high resistance loading
• Digital – precision
6/20/2012
KO6SM
28
Tube Testers
6/20/2012
KO6SM
29
Signal Generators and Oscilloscopes
6/20/2012
KO6SM
30
Very Useful Stuff
6/20/2012
KO6SM
31
Other Important Stuff
6/20/2012
KO6SM
32
Electrical Repairs
• Most common repairs
– Tubes
• Testing
• Transconductance checking
• Replacement
– Re-capping
• Paper, mica and black-beauties
• Power supply electrolytics
– Carbon resistors go up in resistance value with age
– Switch contact and pot cleaning
– Alignment
• Caution not to crack iron slugs
• Peak using S-meter or oscilloscope
• RF signal generator or crystal calibrator
– Put circuit back to original
• Add only trusted validated modifications
6/20/2012
KO6SM
Ohm’s Law
33
Capacitor Problems
6/20/2012
KO6SM
34
Not so bad Capacitors
6/20/2012
KO6SM
35
Replacing Electrolytic Capacitors
6/20/2012
KO6SM
36
Capacitor Testing
6/20/2012
KO6SM
37
Resistors
6/20/2012
KO6SM
38
1930s Resistors
6/20/2012
KO6SM
39
Other Parts – Unobtanium?
6/20/2012
KO6SM
40
Transmitter peripheral devices
6/20/2012
KO6SM
41
Transmitter peripherals
6/20/2012
KO6SM
42
OK, now that you have your vintage radios
restored, who can you talk to and what
frequencies can you use them on?
AM Frequencies in MHz
•
•
•
•
•
•
•
•
•
6/20/2012
160 meters: 1.885, 1.900, 1.945, 1.985
75 meters: 3.855, 3.870, 3.875, 3.880, 3.885
40 meters: 7.290, 7.293
20 meters: 14.286
17 meters: 18.150
15 meters: 21.285
10 meters: 29.000 – 29.200
6 meters: 50.4 (Tucson)
2 meters: 144.450 (Phoenix)
KO6SM
43
…now that you have your vintage radios
restored, who can you talk to and what
frequencies can you use them on?
6/20/2012
KO6SM
44
KO6SM Vintage Station (2012)
6/20/2012
KO6SM
45
AL0F - Collins Station
6/20/2012
KO6SM
46
NE7X – Out grew his old ham shack
6/20/2012
KO6SM
47
WB6ACU - a Rock Star on AM
6/20/2012
KO6SM
48
WA8ULG - “Big Gun” Station
6/20/2012
KO6SM
49
Keep those filaments lit!
6/20/2012
KO6SM
50