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capacitors TC1 and TC2 for maximum output. Keep turning R87 until an output level of 4-
watts is obtained. The receiver should be hearing the transmitted signal. The RF probe should
show an output level of approximately 16 volts under these conditions. On the oscilloscope, the
waveform should approximately match that shown in the next figure.
Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Final Adjustments
Now that the construction of your 2N2/XX PCB is complete, we can go back and do some final tune-
up work to optimize the performance of the rig. We'll do it once here and again after the rig is installed
in the case.
VFO
This step sets up the VFO to 100 KHz of band coverage (50 KHz for 30 Meters) and sets the low end
of the VFO to match the low end of the band. This calibration step requires either a frequency counter
or another receiver capable of receiving the VFO across its tuning range.
[ ]
Connect a speaker or headphones to the "SPKR" jack. Apply power to the PCB. Connect the
frequency counter probe to the top of resistor R40. Let the rig and the counter warm up for ½
hour before proceeding. If using another receiver for this calibration, turn it on and let it also
warm up.
[ ]
Center the RIT potentiometer, R53. Adjust trim potentiometer R78 fully counter clockwise.
Turn the VFO frequency 10-turn potentiometer fully clockwise. Adjust trim capacitor TC6 so
that the upper VFO frequency matches the frequency shown in the table on page 56 for the band
your rig is on. A frequency tolerance of +/- 200 Hz is close enough.
[ ]
Turn the VFO frequency 10-turn potentiometer fully counter clockwise. Adjust trim
potentiometer R78 until the lower VFO frequency matches the frequency shown in the page 56
- Figure 46 -
38
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