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Old September 8th 03, 12:55 PM
Bob Fay
 
Posts: n/a
Default National NC-109 Need some help

I have a NC-109 that I am trying to get working. The radio does receive and
all the functions work somewhat.
The problems are the S-meter will not zero and the tuning does not track
across each band. On each band the radio will align on the lower end and as
you tune up in freq across the band it goes off freq up to 2 mhz with
decreased sensitivity. The broadcast band (A) does track ok but has
decreased sensitivity on the upper end.
The schematic set I have was down loaded from BAMA. This schematic shows
that both the H.F osc and the meter amp should have 105 volts on the plate
which is fed from a 0B2 vr tube. There is 58 volts on these plates. The
vr tube circuit does not match the schematics, nor does the ssb/cw det tube
circuit. My question is should I attempt to try to return the unit to match
the schematic or should I assume that this was a factory change to the unit.
The wiring does look different than the original in these areas.
Thanks for your help.
Bob WC0D