User Manual
45
DECIMAL 3 = “1”
DECIMAL 2 = “0”
DECIMAL 1 (far right digit) = “0”
39. Depress and release the front panel EXECUTE pushbutton switch. This command will enable the front panel
POWER ADJUST pot.
40. Tweak the front panel POWER ADJUST pot fully clockwise to verify that the output power goes to the set
maximum power. Tweak the POWER ADJUST pot counter-clockwise verifying that the output power drops as
tweaking. The output power should be close to 0 Watts when the POWER ADJUST pot is fully counter-clockwise.
41. Adjust the POWER ADJUST pot to the desired output power.
42. If you are not satisfied with the maximum output power, first adjust the front panel POWER ADJUST pot fully
clockwise for maximum power, then adjust the MAX PWR pot (R74) on the SYNTHESIZER to the desired
maximum output power.
43. Replace the cover on the SYNTHESIZER.
44. On the FRONT PANEL CONTROL & METER board, adjust S1 dip-switches with switch 1 and 2 “ON”, and 3 and
4 “OFF”. This places the SRPT-40A back into normal operation.
Reverse Power Calibration - SRPT-40A Only
Note: The SRPT-30 Reverse Power Calibration can only be performed at the factory.
CAUTION
THIS ADJUSTMENT HAS BEEN SET AT THE FACTORY AND SHOULD NOT REQUIRE ANY
FURTHER ADJUSTMENTS.
WARNING
TO MAINTAIN CALIBRATION, NEVER ADJUST THE RP CAL (R17) POT ON THE TWO-STAGE RF
PA BOARD, OTHERWISE THE REVERSE POWER MUST BE RECALIBRATED.
IF IT BECOMES NECESSARY TO RECALIBRATE, READ AND STUDY THIS SECTION
CAREFULLY BEFORE PROCEEDING.
1. Power down the SRPT-40A (i.e., turn off AC LINE switch or turn off external supply).
2. Make sure that the WATT METER is connected to the ANTENNA connector.
NOTE
IT IS PRESUMED THAT A BIRD WATT METER OR EQUIVALENT IS USED.
3. Disconnect the 50-Ohm load from the Bird WATT METER.
4. Rotate the element in the Bird Watt Meter 180 degrees counter-clockwise for measuring reverse power.
5. Remove cover from SYNTHESIZER.
6. On the SYNTHESIZER place jumper on P2 in the RP position.
7. On the TWO-STAGE POWER AMPLIFIER board, tweak the RP CAL pot (R17) fully clockwise (approximately
20 turns).
8. On the SYNTHESIZER, tweak the MAX PWR pot (R74) fully counter-clockwise (approximately 20 turns).