| Author |
Message |
    
fmcvett
| | Posted on Wednesday, May 22, 2002 - 10:18 am: | 
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Replaced both the driver stage (2166) and the outputs ( 2312's ). The voltages are correct on both am and ssb.Only get 2 watts at max. Checked the drive levels and even changed the 2sc1906( rf predriver) and 2sc1973(rf amp& buffer). Any help here? It has me puzzled. Frank. |
307
| | Posted on Wednesday, May 22, 2002 - 7:23 pm: |
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Yep..Start replacing ALL the capacitors in the TX chain AFTER the Finals all the way to the antenna jack. The most likely candidate is the one next to the matching slug. (C-166). The capacitors in question will be in this order , C-166 , C-167 , C-165 , C-160 , C-158 , C-159. You may also check the level with a scope at the pre-driver OUTPUT.(TR-45) It should be about 500 mV P-P. I use a Spectrum Analyzer to help locate where the loss is , but in most cases people do not own them so shot-gunning it is the only way...
307 |
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