Rec 137 a• 141_angl_05042000

Transcription

1
Technické informace 050699
Miroslav Gola / OK2UGS
Assembling Instructions
FM RECEIVER
IN BAND 137 - 141 MHZ
(superheterodyne with double commingling and PLL)
PØIJÍMAÈ FM V PÁSMU
137 - 141 MHZ
SUPERHETERODYN S DVOJÍM SMÌOVÁNÍM A PLL
http://www.emgola.cz/
[email protected]
 2000
AREAL VUHZ CZ-739 51 DOBRA
E-Mail: [email protected]
PØIJÍMAÈ FM V PÁSMU 137 - 141 MHz s displejem LCD
2
FM RECEIVER
IN BAND 137 - 141 MHZ
(superheterodyne with double commingling and PLL)
Assembling Instructions ( the text is enclosed to the set of the component parts and the building blocks )
Update: 31. 01. 2000
INTRODUCTION
The following text is intended for upper-intermediate
radio-amateurs ( not only according to their age ) and it
describes building of an UKV FM receiver for the interesting
band of 137-141 MHz, where the images from the Space are
transmitted with meteorological satellites (views on the
Earth from distance of 850 km or 36,000 km). The receiver
can be assembled and set very easily - only with a support
of a few measuring instruments: a multimeter is enough, and
a simple diode high-frequency probe is optional. For your
education, it is recommendable to use a great deal of special
measuring instruments and learnig, how to use them at this
module. Other details about the assemblage ( users pieces
 2000
of information and update changes ) and about receiving the
Space pictures can be found on the following web address:
http://www.emgola.cz/jak_zacit_meteo.html .
The receiver of signals modulated with frequency ( FM )
is assembled on a base of the Motorola MC3362P integrated
circuit in the function of a superheterodyne with double
commingling with a front-end high-frequency preamplifier
and the low-noise FET BF981 transistor.
The balance of the receiver oscillator and, thereby, a
constant tuning of the selected frequency, is ensured by
3
Obr. 2. Rozloení meteosatelitù na obìných dráhách okolo Zemì
using the frequency exchange (PLL) with the integrated
circuit SAA 1057 working at frequencies from 126.3 to 1303
MHz with a tuning step of 10 kHz.
The receiver is very useful for receiving signals from
meteorological satellites NOAA, METEOR etc. in connection
with the Turnstile antenna ( two crossed dipoles ) or with the
Quadrifillar Helix antenna.
If a frequency converter from 1691 to 137.5 MHz is
connected between the FM receiver 137 - 141 MHz and a
parabolic antenna, it enables to receive very attractive
images from the METEOSAT satellite.
In the above mentioned band of 137 MHz, meteorological
information in WEFAX format from satellites gravitating on
polar orbits in heights approximately 850 kilometres are
transmitted.
After their conversion, WEFAX signals from the
METEOSAT satellite at the geostationary orbit 36,000 km far
from the Earth can be received. Other information about
WEFAX format and its processing ( decoding ) by means of
a personal computer can be found in detail at the Internet
address:
http://www.emgola.cz/wefax_meteo.html
We recommend the introductory literature [1] and other
variants listed in the literature [2] to be read up. We tried to
remake this assemblage and complete it with a frequency
stabilisation by means of PLL and with displaying on a LCD
display.
However, the assemblage can be easily used for reception
in the radio-amateur band 144 - 146 MHz. Details can be
found on the Internet address
http://www.emgola.cz/RX144_146.html
 2000
and in other information enclosed to the WEFAX receiver
kits for frequency band from 137.3 - 141 MHz.
RECEIVER TECHNICAL DATA
Frequency Range: 137 - 141 MHz
Frequency Synthesizer Step: 10.00 MHz
Input Sensitivity: 0.6uV ( rms-type ) for 12 dB SINAD
Intermediate Frequency: 10.7 MHz and 455 MHz
Power: DC 9V ( max. 12 V )
Current Output: 70 mA, according to the loudness level setting
Power Connector: 3 mm ( + pole is inside of the jack pin, - pole
is on its surface!!!)
Automatic Scanning of the Stations in the Band ( SCAN ): Yes
Noise Gate ( SQUELCH ): Yes
Display: LCD 1 x 16 alpha - numerical symbols
Antenna Connector: F type
Loud speaker or Headphones: external 8-25 Ohms
Base Plate Receiver Printed Circuit Size: 138 x 85 mm
Receiver Module Size: 140 x 130 x 45 mm
DESCRIPTION OF THE RECEIVER FUNCTION
The receiver is designed as a superheterodyne with
double commingling, and the MC 3362 ( IC1 ) integrated
circuit by Motorola Company is the heart of the whole
receiver. The scheme of the FM receiver electric connexion
for the frequency range 137 - 141 MHz is shown in the
enclosure, figure No. 1 and its goes out from the literature
[1,2 ]where this integrated circuit was also used for its
excellent properties.
Look through the scheme in the enclosure, figure No.1
and you will certainly appreciate the simplicity of the
electric connexion achieved by using the integrated circuit
MC 3362. Its inside structure [ 4 ] contains all the circuit parts
of the receiver with double commingling including variablecapacitance diode for a resonant circuit of the first oscillator.
At the power voltage higher than 2V you will get excellent
and simple receiver with high input sensitivity. The signal
coming from the antenna is brought through the ANT input
to a resonant circuit that consists of the coil L1 and of the
capacitor C3. The input amplifier T1 is complemented with
a transistor with a low noise number of the BF981 type. The
electrode G1 of the transistor T1 is connected to the hot
ending of the input tuned circuit L1 and the G2 electrode is
connected to a voltage divider that consists of R1 and R2
resistors.
Meteosat 7, který pøedává
meteo snímky na Zemi
ze vzdálenosti 35 900 km
The amplified signal is led through the resistor R3 to a
triple band-pass filter that consists of resonant circuits L2 C5,
L3 C8 and L4 C11. The circuits are freely connected to the
capacitors C6, C7 and C9, C10. The transistor T1 is through
L2 fed with a voltage of 5 V from the stabilised supply with
IC5. From a band pass filter is the signal led through the
buffer capacitor C12 to the input (pin 1 ) of the integrated
circuit IC1.
The structure of the circuit IC1 enables simple and steady
receiver construction where only a few outside passive parts
are connected - the crystal 10,245 MHz, the filter of the first
intermediate frequency 10,7 MHz and the filter of the
second intermediate frequency 455 kHz.
The tuned circuit of the first oscillator L5 and C33 is
connected to pins 21 and 22 of the circuit IC1. In the inside
circuit structure there is the double variable capacitance
diode connected to these pins as well. If the circuit IC is fed
with 5 V voltage, the tuning voltage for the varicap of the first
oscillator is in the range from 0.1 to 4.2 V. The tuning voltage
is brought through a filter to the pin 23.
The oscillator oscillates at a differential frequency ( e.g.
137.5 - 10.7 = 126.8 MHz ). It is pre-set at a frequency value
of 10.7 MHz lower than the average value of the received
band. Behind the first mixer in IC1, a differential component
(fIN -fOSC) of the first intermediate frequency 10.7 MHz is
amplified in the inside amplifier of the circuit IC1 and it is
brought to a ceramic filter F1. A standard ceramic filter
muRata 10.7 MHz for broadcast radio-receivers with the
best band width to 180 kHz or less was chosen for its
common availability .
After filtration through the ceramic filter F1, the differential
component is brought to the second amplifier, where it is
mixed with a signal of frequency 10.245 MHz coming from
the crystal controlled oscillator ( X2 ). A signal of the second
intermediate frequency is generated at the frequency of 455
kHz which goes through a ceramic filter F2. A filter with the
band-pass of 30 kHz is the most suitable for a narrow
bandwidth FM WEFAX.
 2000
4
The resultant differential component with a frequency of
455 kHz is, after going through the filter F2 and after
amplification, brought to a quadrate demodulator that
works with L6 and C19. All pass network L6, C19 of the 455
kHz demodulator is connected to the output 12 of the IC1
circuit and it is charged with the resistor R6 with the value
of 18 - 56 kiloohms. A linear characteristic of the demodulator
with a width of at least 30 kHz is needed for a distortionless
WEFAX signal. For the first experiments ( but extemporary
only ) a 455 kHz ceramic filter from an intermediate frequency
of a common AM radio receiver with a band width of 9 kHz
is sufficient. However, received WEFAX signal is very distorted
and images nearly illegible.
A steady component of the demodulated low-frequency
signal from the output 10 ( MetDriv ) of the IC1 circuit is led
through R4 to the potentiometer P1 with which a sensitivity
sill of the noise gate ( SQUELCH ) can be set. At the output
11 ( Carrier Detect ) of the IC1 there is a control signal for the
noise gate switch at the level of 0 V ( when the signal has no
noise ) or 5 V ( when it is a signal with noise - connection to
setting the values of resistance P1 ). The low-frequency
signal path ( MUTE ) is disconnected at the level of the
control voltage of 5 V at the output 11 IC1 which is after
conversion to T2 led to the output 8 of the circuit IC2 ( the
amplifier of the receiver final stage ). The voltage close to the
zero level at the output 11 IC1 then releases the lowfrequency signal through the IC2. The T3 transistor
commensurate with the pre-set noise gate level by means of
the potentiometer P1 generates the logic signal SQ OUT by
which a mode of the automatic signal searching in the
received band ( SCAN ) is controlled. Steadiness of the tuned
frequency is provided by a frequency synthesis ( PLL ) Philips
SAA1057 (IC4). It is a one chip synthesiser for tuning radio
receivers [ 3 ] in bands of U.H.F., and long waves to short
waves. Working frequency value is set to 120 MHz by the
manufacturer. Nevertheless, it can be easily exceeded up to
the frequency of 160 MHz ( provided circuit selection).
In the connexion, figure No. 3 of the Assemblage
Instruction Enclosure - the synthesiser SAA1057 - IC4 is able
to change tuning with the maximal tuning voltage up to the
voltage 4.2 V in the frequency range from 110 MHz to 150
MHz. For the first commingling in the FM137 receiver, a
signal with the first intermediate frequency lower of 10.7
MHz is used. For the basic receipt range from 137 MHz to
141 MHz the generator generates frequencies in the range
from 126.3 MHz to 130.3 MHz ) from 137.0 - 10.7 = 126.3
MHz up to 141.0 - 10.7 = 130.3 MHz ) with a discrete step
of changing the tuning of 10.0 kHz.
R14, C25 and C26 are passive parts of the phase detector
and C27 serves for filtration of the inside stabilised voltage.
C28 and R15 set the time constant of the active low-pass
which is a part of a chip. In the majority of the applications,
a reference frequency is set by an internal oscillator 4 MHz
- which is controlled by an outside attached crystal X1. We
have chosen saving connexion with a common crystal for
PLL and a microcomputer. The X1crystal is a part of the IC3
microcomputer oscillator. A reference frequency is led
through the capacitor C24 and the resistor R11 for the IC4
circuit. A signal from the first oscillator of the IC1 circuit (
lower of 10.7 MHz than the received frequency ) is led to the
5
output 8 ( FFM ) of the IC1 circuit. The tuning voltage ( max.
5.5 V ) is led from the power to the output 7 of the IC4.
Control inputs CLB, DLEN, DATA are connected to the port
P3 of the IC3 microcomputer.
The guiding word and the word for setting the ratio of
division is provided by a synthesiser ( IC4 ) through a threewire bus C-BUS from the port P3 of the ATMEL AT89C2051
(IC3) microprocessor. Description of the SAA1057 synthesiser
was presented in the literature [2,3,5]. The resultant frequency
of the first oscillator of the IC1 circuit can be gently tuned
with a capacity trimmer C21. The signal from the oscillator
buffer ( pin 20 ) in the IC1 is led to the input pre-divider of
the IC4 synthesiser through the C35 and the R18 ( pin 8 ).
Here, the frequency can be checked by means of a counter.
The available tuning frequency for the inside varicap is at the
output 23 of the IC1.
The needed power voltage of 5 V for the carrier current
( high-frequency ) circuits of the receiver and 5 V for the
synthesiser stabilise the integrated regulator tube IC5 ( 7805
). Moreover, the power voltage for the sensitive input highfrequency parts of the receiver is separated by means of the
TLM2 choke. The antenna pre-amplifier can be fed by
means of an coaxial cable if the jumper JP2 is connected
through the high-frequency switch with the choke TLM1 and
C1. The low frequency pre-amplifier IC2 is directly fed with
the voltage of 12 V from the input connector U12 = V.
Therefore, it is necessary to use an adapter with stabilisation
220 V AC to 9 - 12 V DC for feeding the receiver.
DESCRIPTION OF ASSEMBLAGE THE RECEIVER
WITH LCD DISPLAY
First of all, make sure you have received all the appropriate
components and then divide them into particular groups
according to order of assemblage into printed circuit boards.
Measure the resistance ( in Ohms ) of the resistors with a
multimeter and sort them according to their values. Number
code on coloured stripes on the surface of the resistors can
be helpful. More details can be found in the Assemblage
Instruction Enclosure. Familiarise yourselves with marking
the values of all the employed parts, especially ceramic
capacitors ( e.g. a label 330 means the capacity value of 33
pF, 100 is the capacity value of 10 pF or 101 means that the
capacity value equals 100 pF ). This knowledge makes
completing the printed circuit boards ( Printed Wiring Board
) easier. Every such a mistake - inserting a component to a
wrong position in printed wiring board - will require much
time at energising the module. Therefore there is no point in
hurrying up with the preparation and it is useful to pay
enough attention to it.
Attention: Use a high quality tubular tin solder Sn60 to
solder the components on the printed circuit board and if
it is possible, use a high quality soldering lamp with a
temperature adjustable soldering pin. If you are beginners
- practice soldering technique on an old useless piece of
printed circuit board. If you work with a soldering lamp,
foment the required place first and then apply a tubular
with a tin solder. You will prevent from burning a hole into
Obr. 4 Schéma zapojení pøijímaèe
 2000
Antenna
6
Power
Frequency 137 - 141 MHz
UP - Down
Volume
Squelch
the applied solder ( oxidation ) and making an improper link
which can cause unexplainable fails of the proper function
or a total failure after a short time of using the assembled
module. Such a failure is complicated to find, especially for
a radio - amateur without special facilities. The other
extreme - fomenting the point of soldering for a short time
period, imperfect melting of the solder and making tin
hillocpieces around the soldering place endangers proper
function of the module being assembled as well. These are
cold linpieces that deteriorate the proper function
reliability of the module being assembled. Well - soldered
component has got only minimum amount of the glossy tin
solder around its outlet.
Before starting to place the components, scan both the
printed circuit boards ( Printed Wiring Board ) and mend the
possible bugs. Then fasten four pieces of distant poles to the
ports in the bigger board corners (basic printed wiring board)
using M3 bolts. Start to place the components according to
the figure No. 2 and the list of components in the enclosure.
Proceed from the smallest components to the largest . First
of all, put and solder the resistors, then other passive
components, transistors and integrated circuit bases. There
is one exception - U1 (MC3362) integrated circuit must be
soldered directly to the board. Others will be inserted into
bases, but only during energising the receiver.
There are inductances - wound coils inside metal covers
- in the receiver. Referring to the scheme - figure No. 1 - you
can find the inductance L1 at the input before the transistor
T1, L2 - L4 in the bandpass, L5 in the oscillator and L6 in the
 2000
Obr. 5. Osazovací schéma pøijímaèe
quadrature demodulator. Wind the coils L1 to L5 with 2.75
turns of the enamel wire CuL 0.215 mm at the framework
spindle with a diameter of 5 mm, closely and tightly, a turn
by turn. All the turns must be wound the same direction ( e.g.
clockwise ). Place the winding to the framework, as close to
its base as possible. Solder the wire endings to the two closest
metal pins at the bottom part of the framework ( for better
orientation - coil wire outputs should be soldered to the pins
at the plastic fin side ) and the winding should be protected
with bee wax. Insert L1 - L5 coils to larger ( basic ) printed
circuit board and put a metal cover over the framework
pieces so that the distance between its bottom edge and
printed wiring board is approximately 0.5 mm. This fact is
important - because it will prevent from an accidental short
circuit to the metal cover shealth from some of the printed
wiring board inputs for the coils. Some cover designs do not
require this precaution, nevertheless, do not rely on it. After
checking the right orientation of the outputs in the printed
circuit, solder the coils and its metal covers carefully.
Finally, screw in the ferrite cores made of N01 ( 150 MHz Pramet Sumperk ) material. Complement L5 coil of the
discriminator tuned circuit with a common intermediate
frequency circuit 455 kHz. Place the metal cover
approximately 0.5 mm above the board and solder it. Some
discriminator types have got five outputs - two and three in
two opposite lines. Our printed circuit board is not suitable
for such a design of the L6 coil, therefore cut the middle (
third ) output with pliers before using it within the board. If
the discriminator demodulation coil has got a capacitor in its
7
shealth, do not use the C19 capacitor for the board, then.
For the present, do not complement the basic board with
the ceramic filters F1 and F2 of the intermediate frequency
amplifiers 10.7 MHz and 455 kHz. You will need their
places for connecting a measuring instrument sensing head
during the energising process. For the receivers with the LCD
display - the positions for TL1 and TL2 buttons at the receiver
basic board must remain vacant! For this type of the receiver,
pre-selection switch DIP4 is used. Solder the 5 V voltage
stabiliser IC5 directly to the board, it is not necessary to
provide it with a cooler. Finally, complement the board with
the L1 over L6 coils and the crystal resonators X1 and X2.
The other ( smaller ) printed circuit board is intended for
LCD display, two potentiometers P1 and P2, a trimmer P3
and two receiver function control buttons TL1 and TL2. The
board does not consist of many parts, which makes
complementing the board easy. The positions of the
components is shown in figure No. 3 in the Assemblage
Instruction Enclosure. First of all, insert and solder the P3
trimmer into the board, but do it from the back, from the side
with no service print on it. The resistor R10 is used when the
models with LCD display have got illumination. Insert the
16-pin connector bridge from the front to the upper gaps line
and solder it from the back. The connector bridge must be
orientated endways to the printed wiring board . Insert the
connector bridge to the LCD display ports form the opposite
side and solder it as well. Make sure to that the display is
parallel to printed wiring board. The connector bridge can
be supplied with a connector placed in LCD display ports to
achieve a taking apart connection between the display and
the receiver. This is practical if you intend to use the display
for various other applications. Finally, insert the two buttons
to the printed wiring board from its front side to the ports at
the right and solder them. Connect this structural unit
(printed wiring board complemented with according to
Figure No. 3 ) with the receiver basic board by means of a
connector bridge with eleven pins ( in the angle of 90° ). Insert
one side of the bridge to the receiver basic board and the
other one to the LCD display carrier board. Before this
operation, however, the potentiometers P1 and P2 must be
inserted to the prepared printed wiring board ports and only
some turns must be put on the spindle attachment nuts.
Notice that there is no top-coat of the non-soldering mask
at the corners of both the printed wiring board which fay
during the assemblage. Join both the printed wiring board
together by soldering them at these points. After checking
the mutual plumb of both the printed wiring board boards the receiver basic board and the front panel with a display,
and after a possible correction, solder the connector bridge
at both its ends and the two triplets of the outputs at the P1
and P2 potentiometers. At last, fasten the nuts at the
potentiometer spindles. Details of the assembling unit can
be found in the Assemblage Instruction Enclosure, in the
photograph that exceeds the best description.
For assembling the receiver option with LCD display, the
microprocessor AT89C2051 will be provided with a
programme labelled RX137DIP4X. After energising, the
receiver can be built into an appropriate plastic or metal box
with ports for the display, two buttons, the potentiometer
noise gate ( P1 ) and the volume controller ( P2 ). The antenna
connector and the power connector 9 - 12 volts with the
central pin connected with (+) positive and external connector
shealth connected to ( GND ) will be placed at the back
panel.
RECEIVER ASSEMBLAGE DESCRIPTION ASSEMBLING THE RECEIVER WITHOUT LCD
DISPLAY
The option of the receiver with the LCD display can be
unneeded luxury for many people, mainly, if they decide to
receive the most popular meteosatellites only. For this case,
setting of the working frequency with the switch DIP8 which
is placed on the printed circuit board is sufficient enough.
Other possibility is to count the number of the button presses
in the direction UP or DOWN with a step of 10.0 kHz.
Therefore, complement the receiver basic board only
and keep the display board for a possible future changes.
Complement the basic board with the two buttons TL1 and
TL2 and then place the potentiometers P1 and P2 to the
printed circuit and solder them as well. As the potentiometers
are not fixed in the panel, it is recommendable to make the
two triplets of their outputs steady by soldering them at the
top of the printed circuit board. Put the switch DIP8 to the
frequency pre-selection position.
If you decide to use the display board as well, proceed in
accordance with the installation of the receiver with LCD
display ( insert the potentiometers P1 and P2, complement
the connector bridge, solder ... ) just the resistance trimmer
P3, resistor R10 and LCD display will not be complemented.
Obr. 6 Schéma osazení èelního panelu s displejem LCD a alternat. instalovanými potenciometrytlaèítky TL1 a TL2
 2000
Put the buttons TL1 and TL2 to the display board and leave
the holes for them on the basic board empty. The
potentiometers P1 and P2 are hence fixed better than just
with soldering their outputs to the basic board. The
microprocessor AT89C2051 will be provided with a
programme labelled RX137DIP8X.
LIST OF THE ASSEMBLING COMPONENTS:
CAPACITORS
1pF ceramic (SMD 0805) C6,C7,C9,C10 - 4 pieces
3p3 ceramic C2 - 1 piece
10pF ceramic C33 - 1 piece
12pF ceramic C5,C8,C11 - 3 pieces
1,8 - 22pF capacity trimmer (CKT1 8-22pF) C21 - 1 piece
33pF ceramic C22,C23,C24 - 3 pieces
47pF cer. C19 (complement only if it is not a part of L6 455kHz) - 1 piece
2n2 foil WIMA C25 - 1 piece
4n7 foil WIMA C37 - 1 piece
10nF ceramic C35 - 1 piece
10nF foil WIMA C26, C49 - 2 pieces
47nF ceramic C4,C30,C32,C36,C39 - 5 pieces
47nF foil WIMA C38 - 1 piece
100nF 9 ceramic C1,C15,C16,C17,C18,C34,C43,C44,C47 - 9 pieces
2M2/50V radial electrolytic capacitor C20 - 1 piece
10M/50V radial electrolytic capacitor C45 - 1 piece
47M/12V(25V) radial electrolytic capacitor C27,C29 - 2 pieces
100M/15 radial electrolytic capacitor C40 - 1 piece
8
BASE DIL20 low for IC3 - 1 piece
F-KON FC-017 1 Antenna connector F+M (Put on the receiver basic board
and solder) 1 piece
Distant piece M3x5 mm 4 pieces
Nuts M3 Fe/Cd - 4 pieces
Connector SCD-016A 1 power socket 12V-2,5mm ( Put on the receiver basic
board and solder ) - 1 piece
Connector SCP-2009C 1 socket 12V-2,5mm (Connect to the cable into the
adapter - attention: polarity! ) - 1 piece
Connector CINCH SCJ-0363 1 GM Electronic (Solder into the board at
REP. position ) 1 piece
Switch DIP 4x GM Electronic (Solder into the board only if using the LCD
type ) - 1 piece
Switch DIP 8x 1 GM Electronic (Solder into the board at the DIP position,
versions without LCD only ) - 1 piece
Button P-B1720 switching GM electronic (Solder into the display board at
the position TL1. TL2, in the version with LCD) - 2 pieces
Button P-B1720 switching GM electronic (Solder into the basic board at the
position TL1. TL, the variant without LCD display) - 2 pieces
Instrument button GM electronic, at the spindle with a diameter of 4mm
(Put on the P1 a P2 potentiometer spindles) - 2 pieces
REZISTORS, TRIMMERS A POTENCIOMETERS
2R2 R20 - 1 piece
47R R3 - 1 piece
180R R14 - 1 piece
820R (adjust the display contrast ) R10 - 1 piece
3k3 (2k7 value can be use as well ) R8, R9, R11 - 3 pieces
4k7 R17,R18 – 2 pieces
10k R5,R7,R16, R19 - 4 pieces
22k R4 - 1 piece
39k R6 (39K - 56K - refer to the text) - 1 piece
47k R12,R13 - 2 pieces
50k/G potentiometer TP160, spindle 4mm P2 - 1 piece
100k/N potentiometer TP160, spindle 4mm P1 - 1 piece
100k R1, R2 - 2 pieces
100k trimmer PIHER PT6VK100 P3 - 1 piece
180k R15 - 1 piece
INTEGRATED CIRCUITS
MC3362 RX FM 2x MF IC1 – 1 piece
LM386 NF amplifier IC2 – 1 piece
Microprocessor Atmel 89C2051 with the programme RX137DIP4X IC3
(LCD version only ) – 1 piece
Microprocessor Atmel 89C2051 with the programme RX137DIP8X IC3 IC3
(versions with no LCD only ) – 1 piece
SAA1057 PLL do 160 MHz IC4 – 1 piece
LM7805 Stabiliser +5V IC5 – 1 piece
LCD-DV-16100 One line display LCD1 – 1 piece
TRANZISTORS A DIODS
BF981 2 GATE MOS FET T1 – 1 piece
BC238 NPN universal TO92 T2,T3 – 2 pieces
RED LED any LED diode D1 – 1 piece
1N4007 rectifying diode 1A D2 – 1 piece
TO220
COILS
7MC455kHz TOKO 455kHz/600uH L6 - 1 piece
CHOKE 560nH - 1 uH axial design TLM1,TLM2 - 2 pieces
Wind L with the inductance of 0.1uH 2,75z. refer to the kit L of the circuit
L1,L2,L3,L4,L5 - 5 pieces
OTHERS
X-TAL 10.245MHz Crystal X2 - 1 piece
X-TAL 4.000MHz Crystal X1 - 1 piece
F 455 kHz/15kHz 1 ceramic filter F2 - 1 piece
10.7MHz ceramic filter F1 - 1 piece
 2000
TO92
9
Breaking pins S1G11W GM Electronic (Solder at the position PANEL and hereby
connect the receiver basic board with the display ) - 1 piece
Loudspeaker Conrad Electronic (Solder into the basic board at the position
REP.) - 1 piece
Tubular tin solder 1x200 mm Do not waste the solder - there should be
some left - 1 piece
Printed circuit - Basic board 144-146 138x88mm - 1 piece
Printed circuit - Display board 144-146 138x38mm - 1 piece
Technical data concerning the semiconductor devices
used in this make can be found in the site
http://www.elektronikforum.de/ic-id/
or refer to this link
http://www.chipdir.com/chipdir/chipdir.html .
DESCRIPTION OF THE RECEIVER SETTING
First, pay attention to the power supply. This can be
divided into the transformation part outside of the receiver
( a professional adapter transforming the line voltage of 220
V into the safe voltage 9-12 volts ) and into the 5 volts
stabiliser at the receiver basic board. For emergency and
temporary cases a power supply with only a transformer can
be used ( however, always, to keep you well-being, it is
advisable to use a reliable professional product having the
appropriate certificates - e.g. from HAMA company ), with
a rectifier and an electrolytic smoothing capacitor. The
central port of the supplying adapter is connected to the
voltage of +9 ( +12 ) volts and the external cover is connected
to the GND. This can be verified by measuring with a
multimeter. The basic board is provided with a connector
labelled U12V ( the voltage at the central pin is supposed to
be positive, the cover is at the potential GND ) which is
connected to the adapter connector. The scatterbrained
constructors can be pleased with a safety diode D2 that is put
in the power supply to prevent from reversing of polarity of
the power supply. However, it is not a heal-all.
If you work carefully and properly while complementing,
there should occur no problems at the power energising.
Check, with a voltmeter, the +5 V voltage at the stabiliser
output with the IC5 circuit and +9 V ( +12 V ) at the output
6 of the IC2 circuit. If there is the possibility, watch the stress
distribution at the IC5 stabiliser output by means of a
oscilloscope probe. No flashes or higher noise should be
recognised.
The receiver board has been complemented with all the
components of the receiver part, including the tuned circuits
L1 - L6, nevertheless, there are no MF ceramic filters F1 a F2
yet. Next, put an integrated circuit - the low-frequency
amplifier IC2 to the base.
Do not complement the circuits around the PLL synthesiser
and around the ATMEL microcomputer yet.
The energising and setting procedure of the highfrequency ( HF ) receiver parts depends mainly on the
constructors technical equipment - HF devices - of the
measuring working place. It is important mainly if a fault
occurred during complementation.
In such a case, the HF probe connected to the multimeter
or even to an old AVOMET will not be sufficient.
For setting the resonant circuits at the receiver input and
the discriminator circuit use a wobbler or a combination of
HF generator ( even an improvised one for the considered
receiver frequency band in the range of tuning in of the
 2000
testing oscillator 137 - 141 MHz, so called beacon, together
with a counter ) and the HF diode probe with a multimeter.
Connect the 7IC1 pin through the carrier coupling
capacitor with the signal of the frequency 455 kHz, preferably
with modulated frequency. Connect the oscilloscope to the
pin 13 of the IC1 and tune the maximum amplitude of the
demodulated signal through the L6 coil. If there is a possibility
to change the FM modulation swing, increase it step by step
and watch the changing demodulated voltage. By changing
the values of the damping resistor R6 ( lower value of the
resistor resistance = extending the linear part of the S curve,
the recommended range of the R6 resistor values is 18 - 56
kiloohms ), try to reach at least 25 kHz of the wide linear part
of the demodulation characteristics ( S curve ). If using a
generator without lift regulation it is necessary to change the
input frequency 1 kHz by 1 kHz for both sides from the
central frequency and register the output direct voltage at
the pin 13 of the integrated circuit IC1 into a diagram. Then,
the width of the linear S curve part can be read from the
graph.
The last possibility is to determine the R6 value
experimentally during the auditory tests and by watching the
display image quality ( minimal noise, the highest loudness
level and mainly acuteness of the image details ). The best
value will be probably 18 - 39 kiloohms. Now, solder the F2
ceramic filter ( 455 kHz / 30 kHz ) into the printed wiring
board.
Next step of the setting will be connecting the generator
wobbler output or the analyser output to the receiver antenna
input. Connect the wobbler probe input at the pin 19of the
IC1 ( ceramic filter F1 has not been connected yet ). The
wobbler screen will now be able to display the input part
characteristics which is not influenced with the probe
capacity. Damp L1 with the 50 ohm resistor and tune the
band pass filter with L2, L3 and L4 to the centre of the band
pass 139 MHz and set the width of the band pass filtration to
the value from 137 to 141 MHz. Optionally, by changing
C6, C7 and C9, C10 ( 0.5 - 1 pF ), make the reverb circuit
coupling critical or moderately higher. Remove the damp of
the L1 and tune it to the centre of the received band, to the
frequency value of 139 MHz.
If there is no wobbler available, connect an optional
generator for 137 - 141 MHz ( e.g. a monotransistor make of
Colpitts oscillator together with a counter ) to the antenna
input and tune the reverb circuits using the above mentioned
way for the minimal noise in the demodulated signal, is
sufficient. This can be done after the synthesiser PLL energising
( will be described later ).
Now, put the F1 filter and all the synthesiser and
microcomputer components on their place. After powering
up, the communication should be visible on the attached
oscilloscope at the pins 8 ( CLB ), 9 ( DLEN ), and 11 ( DATA
) of the circuit IC3 between the microprocessor and the PLL
circuit at TTL levels. The sequence of pulses must be
displayed there after the microprocessor sends new data to
the synthesiser.
Set the range of the PLL loop catching . Measure the
tuning voltage at the pin 23 of IC1 with a voltmeter. If
everything is all right, the voltage must be steady and it,
during tuning over with the ferrite core in the coil L5, must
be in the range of 0.4 V and 4.2 V. At frequency of 141 MHz
at the display, set the tuning voltage to the value up to 4 volts
by turning the ferrite core in the L6 coil. Then apply wax
drops to the core in the framework. Failing this, when the PLL
loop does not want to catch, check, using the counter, if the
oscillator frequency is not out of the range. If the value of the
tuning voltage oscillates around the down stop (
approximately 0.3 V ), the oscillator oscillates too high and
vice versa. In this case, changing the capacitor C33 value
appropriately will be sufficient to solve the problem. If the
tuning frequency is at the top limit at even the lowest coil L5
inductance ( with the ferrite core nearly screwed out), it is
recommendable to decrease the capacitor C33 capacity and
vice versa. If using the recommended materials in the L5
reverb circuit and the recommended capacitor C33 capacity,
no problems occur. However, we uncompromisingly expect
your precise work when winding and complementing the
circuits being tuned. For the frequency of 141 MHz we
selected the PLL voltage value of 4 volts for setting. For other
set frequencies in the range 137 - 141 MHz the voltage will
always be lower. E.g., for the received frequency of 137.50
MHz - the NOAA 12 satellite ( the receiver oscillator
oscillates at 126.80 MHz ), the expected voltage value in the
junction R16, C31 can be approximately 2.5 volts. After that,
check the actual oscillator frequency by means of the
counter. For the frequency of 137.62 MHz at the receiver
input, the counter connected to the oscillator will read the
frequency of 126.92 MHz. By changing the trimmer C21
capacity adjust the oscillator frequency to the desired value.
All this can be done provided a perfect connection between
the synthesiser and the master microprocessor IC3.
Replace the high-frequency generator at the input of the
ANT receiver with the TURNSTILE antenna ( without any
pre-amplifier for the long distance reception for the time
being ) for the frequency of 137 - 141 MHz and tune the
operating frequency of the favourite satellite NOAA12 with
the DIP1 switch. When all the switches are in the OFF
position, the oscillator frequency is tuned to the value of
126.80 MHz ( the NOAA12 satellite ) by means of the PLL
circuit and the received frequency is set to the value of
137.500 MHz.
If you turn some of the DI P ( DIP 8 x with eight switches
- for the receiver without the display ) to the position ON,
set the receiver frequency according to the table, listed in the
Assemblage Instruction Enclosure. E.g. - the DIP4 switch has
no switched contact ( K0 selection ), the oscillator is set to
126.800 kHz and the frequency being received is 137.500
MHz. Or the contact 1 ( K selection ) of the DIP4 switch is
switched, the oscillator is set to 130.300 MHz and the
frequency being received is 141.000 MHz.
It is possible to increase the frequency, step by step of
10.0 kHz, from the switch frequency setpoint DIP4x, using
the button TL1_UP. The same operation can be done with
the TL2_DOWN button in the down part of the band being
received. After switching on the receiver, the frequency
adjusts according to the actual position of the DIP switch.
One DIP switch can be in the ON position at the time only.
If the situation does not correspond with this, the oscillator
frequency is set according to the position of the switch with
 2000
10
Obr. 7 Anténa Turnstile 137 MHz pro kruh. polarizaci
50
5
50
5
m
m
m
m
5
50
mm
50
λ/4.k
50Ω
5
m
m
λ/4.k
75Ω
(54xk=cm)
(54xk=cm)
k= koeficient zkrácení
pouitého kabelu
75Ω
libovolná délka
koaxiálního kabelu
Obr. 8 zapojení antény Turnstile pro kruh. polarizaci
11
the lowest sequence number and the buttons TL1 and TL2
keep their function.
HAVE YOU GOT ONLY MULTIMETER IN YOUR
ELECTRONIC LABORATORY?
Even in the laboratory equipped just with a common
sense, multimeter and probably with a high - frequency
probe, completing the receiver assemblage can be done
successfully. The main condition is highly precise work
during complementing the printed wiring board with the
components of the required values and mainly it is necessary
to place them on their appropriate position. The multimeter
will be used for reading the resistor values and for learning
the properties of the used capacitors before putting them on
the printed wiring board. Another condition is a reliable
function of the oscillator with the L5 and the C33 and
flawless communication between the PLL loop and the
microprocessor.
The oscillator function with L5 has already been checked
in accordance with the description in the previous chapter.
Now, it is the time to set the input tuned circuits L1 - L4 to
the resonance for the lowest noise in the output low frequency signal.
Set the pre - selection switch DIP4 or DIP8 at all the
positions to OFF, by this, the oscillator tunes to the frequency
of 126.8 MHz and the supposed signal at the receiver input
shall occur, with the frequency of 137.5 MHz. Connect the
Turnstile antenna ( or a makeshift of it - a piece of a wire of
the length about 110 cm ) to the receiver input. Wait for the
NOAA12 satellite pass and during this pass set the tuned
circuits to the best reception. If you do not manage to do it
during the pass, you can wait for the next satellite pass or
chose other source of the testing signal flying over your
place, e.g. NOAA14 satellite ( with the frequency of 137.62
MHz ) or NOAA15 ( 137.50 MHz ). In order not to wait for
long hours, there is a programme called TIMESAT1 that is
able to calculate the pass time of your desired satellite and
its position on the sky instead of you. The TIMESAT1 is a part
of the documentation for every EMGO receiver and kit, or
you can load it. It is on the Internet site: http:// www.emgola.cz.
Audio samples of WEFAX signals in WAV format, received
from the NOAA satellites, can be found there as well, for you
to know, what kind of sounds you can expect from the
loudspeaker of the set receiver.
More advanced way of setting the receiver in the terms
of not very well equipped laboratory requires certain
preparation.
First, make a simple monotransistor oscillator for the
frequency of 137 - 141 MHz ( if you do not have the scheme
for it, we will send it to you with pleasure - [email protected] )
together with a printed circuit or you can get the information
from the Internet address: http://www.emgola.cz/easy_vfg.html. You will not be dependent on some of the satellite
pass then. After connecting a piece of a wire to the receiver
antenna connector ( a paper clip shaped to a letter L will do
) set the DIP4 or DIP8 switch to the frequency of 137.5 MHz.
Then, tune over the testing oscillator ( beacon ) frequency to
the frequency, when the noise in the set receiver loudspeaker
disappears or its intensity drops considerably. If you use the
EMGO EASY VFG beacon, you can initiate the frequency
 2000
modulation to the testing signal. The signals being received
can be observed at the pin 13 of the IC1 circuit by means of
the oscilloscope, or they can be checked by listening in the
loudspeaker. First, set the lowest noise in the low-frequency
signal by turning the ferrite core in L6. Set the highest
magnitude of the sound. Then try to tune the input circuits
L1 - L4, step by step, shortening the standby wire antenna (
or by moving the beacon away ) to the lowest voltage at the
pin 10 of the IC1 integrated circuit. Shorten the standby
antenna so as the noise is stressed during listening to the
beacon in the output low - frequency signal, but the desired
signal must not disappear. Further, by turning the ferrite
cores of the L1 - L4 coils look for the core position by which
the noise in the low-frequency signal drops to the minimal
value. A screwdriver ( a tool for tuning ) for this use can be
made of a skewer ( of hardwood - beech or bamboo ) or of
an appropriate piece of plastic - e.g. a narrow stripe of a
printed circuit with a ground edge. This is very important,
because a metal screwdriver is absolutely inappropriate. By
approaching it, the inductance of the circuit being set will be
changed. Attention - the toggle level of the SQUELCH must
be set before this operation by means of the P1 potentiometer
to MIN ( with the button fully right ) and then, after completing
the tuning of L1 - L4 select its switch level by tentative
listening to the signal being received.
Now, the printed circuit board can be provided with an
appropriate plastic or metal box.
CONTROLS OF THE RECEIVER WITH LCD
DISPLAY
The DIP4x switch ( in the receiver type with the LCD
display ) has not got 8 positions as it has at the receiver
without the LCD display, because it would be necessary to
enable 4 pins of the ATMEL microprocessor for LCD display
control.
The microprocessor programme is programmed so as the
operating frequency at the DIP4x switch with four positions
is set in less synoptical binary code, shown in the table of the
Assemblage Instruction Enclosure.
Example: All the switches are in OFF position ( 0000H )
and the receiver oscillator frequency is set to the value of
126.800 MHz and the frequency being received is 137.500
MHz. By using the binary code we get 16 positions of the
pre-selection - refer to the table of the Assemblage Instruction
Enclosure ( attention - at the DIP4x switch, the numbering
goes from one to four from left to right, in the binary code
tables is the lowest bit the rightmost as it is shown in the table
of the Assemblage Instruction Enclosure ). The pre-selection
of the channel being received by means of the DIP4x switch,
during reading the data from the display, serves for setting
the locating point of the tuning element after connecting the
receiver to the power source. After repetitional connecting
to the power, the locating frequency is set according to the
DIP4x pre-selection. It is recommendable to chose and set
the operating frequency of your favourite satellite after
getting the initial experience with the reception at the DIP4x
switch. From the setpoint frequency bz means of the DIP4x
switch, the frequency can be increased by 10 kHz steps ( the
button TL1_UP ). The same operation can be done with the
TL2_DOWN button towards the down part of the band 137
- 141 MHz:, with the TL2_DOWN button up to 137.000 (
PLL 126.300 ) and with the button TL1_UP till 141.000 ( PLL
130.300 ).
The buttons TL1_UP and TL2_DOWN at the front receiver
panel ( the type with the LCD display ) have got double
function: By short pressing the selected button, the receiver
tunes up of 10.0 kHz (UP ) or down ( DOWN ). Pressing the
button for longer time, the tuning becomes quicker and it
stops after releasing the key. The last function enables to
search the transmitter activity in the band 137 - 141 MHz (
Scanning ). First, push and hold the button for the direction
of the desired scanning ( UP - DOWN ) and then shortly press
the other key. The actual frequency in the band will be
displayed on the display and after interception of the carrier
transmitter, the scanning stops for two seconds and a message
TUNING will occur at the display. This is the right time for
pressing any of the two buttons ( if the you are interested in
the signals at the sought frequency ) and the scanning will
stop. The threshold value for searching is set by SQUELCH
( noise gate ).Turning the potentiometer leftmost disables
SQUELCH ( noise gate ) and scanning stops at ever so little
indication of the demodulated signal. At the opposite position,
the tuning goes over and over in the range of t 137 - 141
MHz, after single 10 kHz steps. It stops only after indicating
a very intensive signal ( mostly, as far as the satellite directly
passes your aerial ). Select the appropriate value after having
some experience with the reception.
NOTE: If you are not satisfied with too low SQUELCH
hysteresis, connect the pins 10 and 11 of the IC1 (
MC3362 ) with a resistor ( approximately 5 megaohms
) and connect a ceramic capacitor 100 mF ( SMD
preferably ) between the pin 11 and GND, in
accordance with the Figure 1.
Have a nice reception and we expect your advice, notes
and mainly your reception experience in extreme terms at
the address: [email protected].
HOW TO CONNECT LOW-FREQUENCY
RECEIVER OUTPUT TO YOUR PERSONAL
COMPUTER
After signal demodulation by FM receiver, an amplitude
modulated tone 2,400 Hz occurs at the low-frequency
output. This tone is further processed. Thanks to its reliability,
a very old system of the modulation format WEFAX (
Weather Faksimile ) is used up to the present for transmission
of the black and white pictures through a standard audiochannel. It uses a ( sub - )carrier frequency of 2,400 Hz which
is modulated with an amplitude by a video signal. The
maximal modulation ( black ) is not zero, but approximately
5% and white is 87%.This compound audio signal is then
modulated by frequency to the main carrier, e.g. 137.5 MHz
for the NOAA12 satellite. There are several ways how to
process the demodulated low-frequency signal. We are
going to describe a simple way, based on conversion the
amplitude modulation to the frequency modulation ( refer to
the Assemblage Instructions for the Easy Interface
communicator, the Internet address:http://www.emgola.cz/
easy interface WEFAX.html.
 2000
12
Obr. 9 Obrazovka programu JVFAX 7.1
The frequency change from 1,500 to 2,300 Hz
corresponds to the maximal brightness change. Such an
adapted signal is then led via a simple comparator to the
computer serial port and it is further processed by JVFAX 7.1
programme which is available at the Internet address:
http://www.jvcomm.de
The Easy Interface is described in the individual EMGO
publication and it is sold as a kit or as a completely
assembled functional product. The results that can be obtained
with an uncomplicated and cheap interface are surprisingly
good, however, they do not reach the digital quality of the
picture conversion. Such results can be reached only with
eight-bit analogue to digital converters of more expensive
models or by processing the WEFAX signals with the sound
card supported by JVComm32 programme which is available
for loading the address:
http://www.jvcomm.de
DECODING WEFAX SIGNALS WITH SUPPORT OF
SW JVFAX7. 1a OR JVComm32
Decoding the pictures by means of PC is supported with
JVFAX programme, version 7.0 or 7.1a [10] that can be
configured to many operation modes. For browsing the
received pictures, ZOOM function can be used. This function
enables enlarging the image up to the maximal picture
resolution in the computer memory. Other details can be
found in the JVFAX programme user manual which contains
more then fifty text pages and goes into tiniest particulars.
The user manuals and JVFAX programme in its upgraded
version can be easily obtained from EMGO company. The
WEFAX images are transmitted as black-and-white pictures,
the JVFAX programme allocates them the appropriate colour
scheme. Single images ( bit maps ) are transferable to the
following programmes: Microsoft Word, Corel Draw and
others.
RECEPTION AND DECODING IMAGES V JVFAX
PROGRAMME
( interconnecting RX and PC, programme setting and
control )
Connect the low-frequency output of the receiver to the
Easy Interface input with a single shielded cable, ended with
the CINCH connectors. Connect the CANON 9 output
13
connector of the Easy Interface module with the COM1 port
or COM2 port of the PC with a cable, you have bought ( a
cable for interconnection of the modems - without signal
cables crossing ), or you have made of 3 meters of fourstrand ( shielded preferably ) cable.
the reception and the decoding can be started. Wait for
starting the transmission at your selected frequency and
finish the optimal setting of the low-frequency amplitude at
the Easy Interface according to the frequency analyser unit
of the JVFAX programme. Note: Possible problems with
image decoding can occur if you have a slow PC.
CONNECTING
EASY INTERFACE PATCHCORD - PC COM
IMAGE RECEPTION AND ITS DECODING BY MEANS
OF JVComm32 PROGRAMME - W95/W98/W-NT
( interconnecting the RX and the PC sound card )
Connecting the PC - Interface patchcord
( DB9M/DB9F ):
At the CANON DB9M Interface connector:
3
4
5
6
7
-
TXD ( Transmitted Data )
DTR ( Data Terminal Ready )
GND ( GND Signal )
DSR ( Data Seat Ready )
RTS ( Request to Send )
At the PC Canon DB9F connector:
3
4
5
6
7
-
TXD
DTR
GND
DSR
RTS
Connecting the PC - Interface patchcord
DB25F ):
( DB9M/
At the CANON DB9M Interface connector:
3
4
5
6
7
-
TXD
DTR
GND
DSR
RTS
At the PC Canon DB25F connector:
2 - TXD
20 - DTR
7 - GND
6 - DSR
4 - RTS
After loading the computing storage with JVFAX ( the
computer must be set to work in MS-DOS, not in Windows!!!
), set the basic working mode first in the configuration menu
( letter C ).
Basic setting of the JVFAX7.1 programme:
- interface type - COMPARATOR
- number of bits - ( 5-8 )
- base address of the COM1 or COM2 port
- appropriate IRQ ( you will get a piece of advice form
your experienced friends )
Then select the mode with 240 lines per second (WEFAX)
or 120 lines per second ( FAKSMILE ) and the appropriate
mode. After saving the configuration data at the hard disk,
 2000
Eberhardt Backeshoff, DK8JV, German author of the
JVFAX programme ( for MS - DOS, last upgrade 7.1a ),
introduced an excellent programme called JVComm32 for
decoding WEFAX and FAKSMILE and other modes to the
Internet in 1998.
This can be found at the Internet address: http://
www.jvcomm.de/ or e-mail address: [email protected].
The author expects us to use some of the common 16-bit
sound cards and a computer 486DX with the RAM memory
16 MB, the operation system Windows 95, Windows 98 or
Windows NT 4.0 and a high quality graphic card ( High - or
True Colour ) with the resolution of 800 x 600 pixels at least.
Of course, you can work with older interface models that
communicate with the programme via the PC serial port
COM1 or COM2.
The JVComm32 programme can work at the background
and you can process the received images ( browsing them,
making cut-outs, sending them to your friends via Internet
etc. ). For multiasking, the author recommends Pentium 90
MHz at least and 32 MB of the RAM computing storage as
the necessary minimum.
The programme can be loaded from the Internet address:
http://www.jvcomm.de/ from the DOWNLOADS option.
Connecting the FM 137 - 141 MHz receiver to the sound
card input of the personal computer is very easy. Connect
the receiver loudspeaker output to the Line input of the
sound card. If you want to have the independent loudspeaker
output, lead out, from the receiver junction P2, C37, C38, a
low-frequency signal through a shielded cable to a separate
connector at the receiver back panel and then connect it to
the microphone ( or LINE IN ) input of the sound card. You
can put an amplifier, similar in the make with the IC2,
between the connector at the panel and the receiver output
junction, in case that your sound card has got lower sensitivity.
It is usually not necessary, mainly if you lead the signals to
the microphone port of the card. If you decide to use the
JVComm32 programme, you can forget the simple Easy
Interface for the COM port.
The programme configuration for
reception of the signals from NOAA or
METEOSAT satellites is very easy: set the
NOAA or GEOSTACIONARY mode and the
sound card. An extensive help for the
programme is greatly pleasant for the users
as well.
CONCLUSION
EMGO Company has prepared a receiver kit for you. This
kit contains a complete assembling documentation, bilateral
printed circuits with a non-soldering mask and a service
applied colour, a set of integrated circuits ( MC3362,
SAA1057, ATM89C2051 with the programme RX137DIP4X
or RX137DIP8X, LM386, LM7805 ), ceramic filters 10.7
MHz and 455 kHz/30 kHz, a crystal 10.245 MHz and 4 MHz
and a set of passive component parts ( including the software
for MS-DOS or Windows 95/98 ).
Information and complete price list
is available at the address:
EMGO, Areál VÚH, 739 51 Dobrá, CZ
Via fax +420 /658/ 624 426,
Tel. +420 / 658 / 601 471
and mobile phone +420 602 720 424,
or via E-mail: [email protected]
Rev: 31012000 / OK2UGS
http://www.emgola.cz/Index_angl.htm
14
LITERATURE USED:
[1] Günter Borchert DF5FC, Funkamateur 2/1995, pages. 153 156 Der Wetterfrosch - ein 137 MHz Satellitenempfänger,
continued in Funkamateur 3/1995, page 274
[2] Ing. Radek Václavík OK2XDX, Pøíjímaè a interfejs WXSAT
(pøíjem snímkù z orbitálních meteosatelitù). A-Radio Praktická
elektronika, series of the articles in issues 2-6/1997.
[3] Marík, V.: Kmitoètová syntéza oscilátorového kmitoètu
rozhlasových pøijímaèù, Amatérské Radio B3/1987
[4] Motorola, Linear/Interface ICs Device Data, Vol. II, pages 8-82
[5] Philips Semiconductors, SAA1057 - Radio tuning PLL
frequency synthesiser, November 1983.
[6] ATMEL, AT89C2051 8.bit Microcontroller with 1 kbyte Flash,
katalogue lists August 1994.
[7] DF2FQ: VHF Empfanger, CQ DL 1/1994
[8] Josef Daneš a kolektiv: Amatérská radiotechnika a
elektrotechnika, 3rd part,
Mìøení na pøijímaèích, pages 190 - 254. Nae vojsko Praha 1988.
[9] Tùma, P. Displej s LED. AR A4/94 page 18
[10] Kolomazník, P.: Pamì EEPROM 93C46 AR B6/93, page 208.
[11] Marík, V.: Kmitoètová syntéza oscilátorového kmitoètu
rozhlasových pøijímaèù. AR B3/87, page 88.
[12] OK2UGS.: Pøijímaè FM v pásmu 144 - 146 MHz s obvodem
Motorola MC3362. Elektroinzert 5/97 page 6.
[13] OK2UGS.: Pøijímaè FM v pásmu 144 - 146 MHz s obvodem
Motorola MC3362. A_Rádio_Electus99, pages 73-79.
[14] OK2XDX.: address: http://207.204.29.183/ok2xdx/DK/
DKEN.html
[15] OK2UGS.: address: http://www.emgola.cz
[16] Ing. Radek Václavík, OK2XDX.: Praktická elektronika è. 7/
1999 - popis stavby konvertoru LNC1700 MHz.
Obr. 10 Program JV Comm32 v akci
 2000

Rec 137 a• 141_angl_05042000

Transcription

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