SO
MHz UNIT
Please remove the
144
and 430 MHz units , if
installed , to allow access to test points on the
50 MHz module.
1.
Local oscillator circuit
( 1) Connect the DC voltmeter to pin
2
of the
edge connector f or the 50 MHz unit. Confirm
that 11 volts is present , with the B AN D
switch set to
50-52
MHz. Switch to
52-54
MHz , and check f or 11 volts at pin 3 of the
edge connector.
(2)
Connect the RF probe of the VTVM to the
LOC AL OUT terminal. Confirm that the unit
is oscillating.
(3) Connect a frequency counter to the L OC AL
OUT terminal. Set the BAN D switch to
50-
52
MHz, set the R PT swi tch to S IMP , and
adjust T102 f or a reading of exactly 2 2.0 MHz.
Switch to
52-54
MHz , and adjust TC2 03 for
a reading of 24.0 MHz.
2.
Receiver section
( 1) Set the HF transceiver to 29 MHz, and peak
the preselector against the mar ker signal f or
maximum sensitivity.
(2)
Connect the DC voltmeter to pin 1 9 of the
edge connector , set the BAN D switch to
50-
52
MHz , then
52-54
MHz, and confi rm that
13 .8 volts is present.
(3)
Connect the DC voltmeter to pin 15 of the
edge connector, and rotate the FTV- 901 R
RF GAIN control fully counterclockwise. The
voltmeter reading should be 0 volts. In the
fully clockwise position , it should be 13.8
volts. Afte r confirming these voltages , please
leave the level at maximum gain.
( 4)
Connect the DC voltmeter to pin 1 4 of the
edge connector , and set the FTV-901R TUN E
control to the center position (1 2 o ' clock).
With the BAN D switch in the
50-52
MHz
position, adjust VR1901
for
a reading of
4
volts.
(5)
Connect a signal generato r to the 50 MHz
ANT jac k, and set the FTV-901 R BAN D
switch to
50-52
MHz. Set the signal genera
tor to
51
MHz, and tune the receiver to its
output.Peak VR 1902 T 206 ,T 207 , T 20s ,and T 209
for a maximum reading on the HF t ransceiver
S-meter. Reduce the signal generator output,
if necessary , to secure easy viewing of the
pea k point. Switch to the
52-54
MHz band ,
set the signal generator output to 53 MHz ,
and repeak these transf ormers again while
tuned to the generator frequency. Then
recheck the results at
51
MHz.
3.
Transmitter section
( 1) Connect a dummy load
/
wattmeter to the
50 MHz ANT jack.
Set VR202 and VR203
fully counterclockwise. Set the HF transceiver
DR IV E o r C ARR IER control to the center
its range
(12
o 'clock). Set the BAN D switch
to
50-52
MHz.
(2)
Connect the RF probe of the VTVM to the
collector of Q203. While transmitting , pea k
T10 1 , T102 , Tzo3 , T104 , and T1os for a
maximum reading on the VTVM (0.4 volts
RMS nom.).
(3) Connect the RF pbobe to terminal A on the
50
MHz unit. Peak TC201 and L1os for a
maximum reading on the VTVM ( 4 volts
RMS nom.).
(4)
While t ransmitting , peak TC201 , TC2 02 ,
TC2 03 , TC204 , and TC2 os for a maximu m
power output indication on the wattm ete r.
(5)
Repeat steps
(2)
through
(4)
on the
5 2-54
MHz band. Then recheck the resu lts at
50-52
MHz.
( 6)
Set the FTV- 901 R meter switch to the P O
position , and set the transceiver DR IVE o r
C ARRI ER control f or an output of 1 2 watts
from the transve rter. Set VR302 for a reading
of .8 on the FTV- 901R meter.
(7)
Beginning at zero drive , gradually increas e the
transceiver DRIV E or CARR I ER control until
th e out put f rom the transvert er do es not
increase more. Do not exceed this level.
(8) Rotate VR202 slowly clockwise , until an
output of 1 2 watts is secured across the
50-54
MHz range.
( 9) Set VR 203 fully clockwise.
(10) While t ransmitting , rotate VR30 1 to s ecu re
maximum powe r output on the wattme te r.
(11) Now rotate VR203 fully counte rcloc kwise.
While t ransmitting , rotate VR203 slowly
clockwise , until the powe r output just begins
to fall off. Do not go past the th reshold point.
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