B. RF Power Transistor of Current Adjustment
1) Set the mode selector to USB, and the band
selector to C of CH 19.
2) Connect current meter to TP-9 (+) and TP-8 (- ).
3) Adjust VR 1 î to 10 ± 0.5 mA.
4) Connect current meter to TP-9 (+) and TP-7 (-).
5) Adjust VR 10 to 10Û±5 mA.
C. RF Power Amplifier Adjustment
1 ) Set the Mode Selector to USB.
2) Apply 1,000 Hz 30 mV audio to microphone in-
put circuit (use dummy microphone plug).
3) Set the band Selector to E with CH40.
4) Adjust VR-12 and L-42 for maximum RF output.
5) Adjust L-40, L-43, L-44 and L-33 for maximum
RF output.
6) Repeat steps 3) through 5) until no further im-
provement is obtained.
7) Adjust L-42 for balance of E band CH40 and A
band CH1 with RF output.
D. Two-Tone Adjustment
1 ) Apply 500 Hz a.nd 2,400 Hz (30 mV) audio tones
to the microphone input circuit at the same time.
Use two audio signal generator set with attenu-
ators.
2) Adjust test audio levels of 500 Hz generator by
means of attenuator on the generator so that the
scope present wave figure like 'A ' as shown below.
3) Adjust VR-12 to 12 W p-p power output.
E. AM/FM/CW RF Power Output Adjustment
1 ) Set the Mode Selector to AM.
2) Select the Band Selector to C.
3) Select the Channel Selector to 19.
4) Adjust VR-13 for 5 W RF power output.
F. AM Modulation Adjustment
1 ) Apply 1,000 Hz 30 mV audio to the unît.
2) Adjust VR-14 for modulation depth of gerater
than 90%.
G. FM Deviation Adjustment
1 ) Set the Mode Selector to FM.
2) Apply 1,000 Hz 30 mV audio to modulation
circuit. Use dummy microphone plug.
3) Connect déviation meter (or linear detector) to
antenna output on the unit.
4) Adjust VR-5 to obtain 2-3 KHz.
H. RF power Meter Adjustment
1 ) Set the Mode Selector to AM.
2) Comparing the reading of externat RF power and
the buîlt-in meter, Adjust VR-8 for equal indic
ation on the unit power meter.
I.
CW Tone Level Adjustment
1 ) Set the mode selector to CW.
2) Connet 8 Ohm dummy load and AF VTVM to
ext S.P jack, and connect a key sw to key sw Jack.
3) Key sw on and adjust VR-16 to 200 ± 10 mV.
Reference -SSB Two-Tone Alignment
Important: RV-12 (bias)
Adjustment: RV-12 should
not be rotated clockwise
beyond 2 o'clock position,
or the RF power transistor
will be destroyed.
A.
Properiy adjusted transmitter.
B.
Unequai tones-Adjust generator
Outputs to balance.
C.
Excessive modulation - Adjust
RV12 counterclockwise.
E.
Undermodulation-Adjust RV 12
clockwise.
D.
Final transistor incorrectly bias-
ed-A djust RV 12.
F.
Similar to A but showing hum-
Cbeck for proper testing condi
tion.
- 9
Summary of Contents for Petrusse
Page 16: ...EPT360010Z Main Board PC 14 ...
Page 17: ...Schematic Diagram 1 5 ...
Page 18: ...TIME ...