Got a 2980 on the desk.
Issue is:
When connecting frequency counter to TP3 to align PLL Offset Oscillators, I'm not getting the proper frequency. Using channel 1 on cb band on AM it should be 16.2700mhz, but instead it's 16.2817mhz and the PLL Offset IF for AM makes only a slight change (16.2817mhz up to 16.2819mhz and no less than16.2813mhz).
The SSB PLL Offset oscillators are off about the same and makes very little change up or down.
The Carrier Offset Oscillators won't show on frequency counter at all through R151 and R102 points, but will zero beat just fine using my monitor radio (yaesu ft-950).
Tested with and without bias board in place.
VCO Voltage is just what it should be at 3.20v, VCO Buffers look fair, not the best but fair.
Everything else on radio works as it should.
AM output:
RF Power all the way up = 8w, swinging to 48w PEP and 12w Average.
RF Power all the way down = 1w, swinging to 25w PEP and 8w Average.
SSB = 40w
Power supply voltage is 14.30v.
10k switch works fine, clarifier slides fine, bands work fine, not hacked up at all. Limiters still intact, nothing clipped or removed.
Frequency on internal counter shows for channel 1 for example 26.977mhz.
All caps on regulator/audio side of board has been replaced.
Has the MC PLL, not the RCI 8719.
I went through this radio last year with y'alls help with great success. It's the 2980 that sat in a dilapidated old shed in the hot and cold for 12years with no use, we (meaning you all and myself) brought it back to life. But now the owner noticed the frequencies shifting off a great deal.
Any ideas guys?
Issue is:
When connecting frequency counter to TP3 to align PLL Offset Oscillators, I'm not getting the proper frequency. Using channel 1 on cb band on AM it should be 16.2700mhz, but instead it's 16.2817mhz and the PLL Offset IF for AM makes only a slight change (16.2817mhz up to 16.2819mhz and no less than16.2813mhz).
The SSB PLL Offset oscillators are off about the same and makes very little change up or down.
The Carrier Offset Oscillators won't show on frequency counter at all through R151 and R102 points, but will zero beat just fine using my monitor radio (yaesu ft-950).
Tested with and without bias board in place.
VCO Voltage is just what it should be at 3.20v, VCO Buffers look fair, not the best but fair.
Everything else on radio works as it should.
AM output:
RF Power all the way up = 8w, swinging to 48w PEP and 12w Average.
RF Power all the way down = 1w, swinging to 25w PEP and 8w Average.
SSB = 40w
Power supply voltage is 14.30v.
10k switch works fine, clarifier slides fine, bands work fine, not hacked up at all. Limiters still intact, nothing clipped or removed.
Frequency on internal counter shows for channel 1 for example 26.977mhz.
All caps on regulator/audio side of board has been replaced.
Has the MC PLL, not the RCI 8719.
I went through this radio last year with y'alls help with great success. It's the 2980 that sat in a dilapidated old shed in the hot and cold for 12years with no use, we (meaning you all and myself) brought it back to life. But now the owner noticed the frequencies shifting off a great deal.
Any ideas guys?
