New Refurb Dx 959 Power output choked?

[montecarlossfan]

I just got a refurb 959, I noticed it was not up to par with my other 959's that would swing 15w out of the box and when turned up a bit 20-25 or so.

First I noticed D72 has a double diode instead of single, and D71 has some kind of double diode I believe on it also. Then d145 also has a double diode...As far as I can tell none of these have anything to do with rf output..Now my question is why is this 959 so choked backed compared to others? Is there anything I should look for?

 

[montecarlossfan]

changed to irf520n genuine international recitifier i dunno what the hell they had in there. It swings a little better now and works a little better but still not the same...i checked gate volts 3.8 on each. i studies the schematic more..looks like the 2 diodes is to replace one with a 1.4v drop

 

[Robb]

Almost every Galaxy radio I've worked on needed a real alignment. Dunno if the refurb guys did it to this radio. Maybe - maybe not. Wouldn't hurt too check the TX coils to see if they have been peaked or not. I would . . .

That gate voltage seems a bit excessive to me.
Might try 3.4v instead and see if the thing will still switch on . . .

 

[montecarlossfan]

I got it ...they had a 1n4148 in where the 5.6v gate to source diode is...i dunno wtf they were thinking...I can now key and get decent forward modulation...I dropped the gate voltage to 3.5 , worked fine at 3.4 but at 3.5 ssb sounded much better and looked better on the scope.

 

[Robb]

Sure you know what they were thinking.
They had to pass FCC standards - lol!