Receiver Alignment:
1. Receiver Setup:
Put the mode selector on AM, the RF gain fully clockwise
(maximum gain), squelch to minimum (unsquelched), volume at 2 o'clock, set
frequency to 28.295 MHz, and NB/ANL to OFF. Connect signal generator set at
RF carrier frequency of 28.295 MHz, AM modulated with a 1 KHz audio tone at
30% modulation level.
2. AM Sensitivity:
Connect a SINAD meter to the external speaker jack.
Adjust L3, L4, L6, L7, L8, L10, L11 and L12 for best SINAD.
Increase the RF generator to 1mV RF carrier level.
Adjust L3, and L4 for minimum distortion.
Verify that the receiver AM sensitivity is better than 0.5µV for 10 db SINAD.
3. FM Distortion:
Change the RF generator to the FM mode, 1mV RF carrier level, FM modulated
with a 1 KHz audio tone ± 3 KHz modulation level.
Adjust L5 for minimum distortion.
4. USB Sensitivity:
Turn off the audio modulation of the RF generator, and change it's frequency to
28.296 at an RF carrier level of .5 µV. Set radio to USB RX mode.
Adjust L11 and L12 for audio output greater than 2V.
5. LSB Sensitivity:
Keep the audio modulation of the RF generator off, change frequency to 28.294 at
an RF carrier level of 1mV, set radio to LSB mode.
Adjust L11, and L12 for audio output greater then 2V.
6. NB Adjust:
Set radio to 28.305 MHz AM RX mode, NB-ANL/OFF switch to ON, adjust RF
generator to 28.305 MHz with an RF carrier level of 1mV, AM modulated with a 1
KHz audio signal at 30% modulation. Connect a digital voltmeter to TP1 (R11).
Adjust L1 and L2 for DC Voltage to max ( 1.3V ).
7. AM Scale Meter:
Turn NB-ANL switch to OFF, SWR/S/RF switch to S/RF position, set radio
frequency to 28.305 AM RX mode, RF signal generator setting 28.305 MHz with a
carrier level of 100 µV, AM modulated with a 1KHz audio signal at 30%.
Adjust VR1 so that bar graph reads 6 bars.
8. USB Scale Meter:
SWR/S/RF switch to S/RF position, set radio frequency to 28.495 MHz USB RX
mode, RF signal generator setting 28.496 MHz with a carrier level of 100 µV, no
audio modulation.
Adjust VR2 so that bar graph reads 6 bars.
9. AM Squelch:
Set radio frequency to 28.495 MHz AM RX mode, SQ control fully clockwise, RF
signal generator setting to 28.495 MHz , RF carrier level at 1 mV, AM modulated
with a 1 KHz audio signal at 30%.
Adjust VR4 very slowly until squelch noise just goes off.
10. SSB Squelch:
Set radio to 28.495 MHz USB RX mode, SQ control fully clockwise, RF signal
generator setting to 28.496 MHz , RF carrier level at 1 mV, with audio modulation.
Adjust VR3 very slowly until squelch just goes off.
