5-15. FILTER MATCHING TRANSFORMER.
a.
b.
C.
d.
e.
f.
g.
Adjust the S meter ZERO pot for zero S meter
deflection (S-l ).
With the SIDEBAND switch in USB, tune in the
calibrator signal at 3.8 MHz for maximum S
meter reading.
Adjust the RF TUNE control until the S meter
reads S-9.
Turn the VFO control clockwise to increase the
audio frequency until the S meter drops to S-5.
Adjust T6 and T13 for maximum S meter reading.
Repeat Steps b. through e.
Center the 9.0 MHz oscillator as described in
paragraph 5-9.
3-16. MIXER AND RF ALIGNMENT.
a.
b.
C.
d.
e.
Tune up the TR-4C at 3.8 MHz for maximum
power output into a dummy load. Set the RF
TUNE control on 5. Adjust the XMTR GAIN
control for 0.2 Amperes plate current as indica-
ted by the plate meter. Adjust T7 bottom and
T9 bottom for maximum plate current.
Tune up the TR-4C at 7.3 MHz and repeat a.
above, with the RF TUNE control on 6, by
adjusting T8 top and Tl0 top.
Set RF TUNE control on 5. Tune up the TR-4C
at 14.3 MHz and repeat a. above by adjusting
T7 top and T9 top.
Tune up the TR-4C at 29.7 MHz (crystal not
supplied). With the RF TUNE control at 9%
repeat a. above by adjusting T8 bottom and T l 0
bottom.
Set RF TUNE control on 5. Tune up the TR-4C
at 21.3 MHz and repeat a. above by adjusting
L6 and L7.
5-17. PA NEUTRALIZATION.
a. Attach an RF output indicator between the
TR-4C and the dummy load. If no external
output indicator is available, the TR-4C’s own
RF output indicator may be used.
b. Tune up the TR-4C on 29.0 MHz for maximum
C.
d.
power output into a dummy load.
Reduce plate current to 0.2 Amperes with the
XMTR GAIN control.
While tuning the PLATE control back and forth
through resonance, adjust C76, using an insulated
screwdriver, until the plate current dip and maxi-
mum RF output occur simultaneously. An insula-
ted screwdriver is required because the rotor of
C76 is connected to + 250 Volts DC.
5-18. TRANSMITTER IF NEUTRALIZATION.
With microphone plugged into TR-4C, turn the
VOX gain fully counterclockwise and turn XMTR
GAIN fully clockwise. Place the Mode switch in
the SSB position.
While talking into the microphone, increase the
RCVR GAIN control setting until speech can be
heard from the speaker.
Adjust Cl68 for minimum output from speaker.
If over one turn of adjustment is required, it will
be necessary to realign T14, C 127 and the Carrier
Balance control.
5-19. S METER ADJUSTMENT.
With the RF GAIN control fully counterclockwise
adjust R187 for an S meter reading of 60 dB over
s-9.
Table 5-3. Tube and Semiconductor Complement
REF Component F U N C T I O N
DES
Type
Transmitter Receiver
V1 6EA8
Pre-Mixer/Xtal Oscillator Pre-Mixer/&al Oscillator
v 2 12AV6 Sidetone Oscillator Diode Det/l st AF Amplifier
v 3 6EA8
Cathode Fol. Mixer/Cathode Fol.
v 4 6EJ7
Mixer
v 5 6BZ6
Crystal Calibrator
V6 12BY7
Driver
v7 12BA6
RF Amplifier
