18
1-11-2 UNWANTED SIDEBAND REJECTION
Set up the 44 in the safe mode, power up and allow 15 minutes for warm up. The warm up is important, you
must insure all components are up to operating temperature.
Tune for max power in the center of any band in CW or AM.
1.
Connect mic patch cable, adjust for 5mv, 1000Hz.
2.
Set MIC GAIN to 8.
3.
Set function to LSB
4.
Set spectrum analyzer center freq to 7.23MHz.
5.
Key the transmitter
6.
Adjust the AUDIO Ø BAL and the AUDIO BAL controls for minimum USB signal.
7.
Unkey, switch to USB
8.
Key up, check LSB signal suppression, adjusting AUDIO Ø BAL and the AUDIO BAL controls for
minimum. A slight tradeoff between USB and LSB may be required. But if the minimum setting for one
or the other causes difference of more than 5db a fault has occurred. That fault is most likely a tube
failure.
9.
Return equipment to “safe” mode.
•
Repeat steps 1-5 adjusting RFØL and RFØC for max rejection of unwanted sideband.
Once again, a slight tradeoff between USB and LSB may be required. But if the minimum setting for one or the
other causes difference of more than 5db a fault has occurred. That fault is most likely a tube failure.
This completes the test and adjustments. Go to section
2-2-7, GOING ON THE AIR WITH THE 44.