SX-99 schematic

[N8IE]

Good morning all,
My beloved SX-99 has fell ill. 

I suspect something in the BFO circuit has gone bad, when switched between AM\CW no changes are present and only the strongest of signals are present.

I have noticed for a while, a light "pop" when the radio was first turned on, could be a bad filter cap?

Anyway, I have a copy of the schematic but not one showing voltages, is there such an animal around somewhere?

Thanks es 73
Dan, N8IE

[W3FJJ]

Not sure if the voltages are in the owners manual, but
BAMA has the manual you can download.

http://bama.sbc.edu/hallicra.htm

GL  CHuck

[N8IE]

Not sure if the voltages are in the owners manual, but
BAMA has the manual you can download.

http://bama.sbc.edu/hallicra.htm

GL  CHuck

Thanks Chuck,
I guess this is a case of RTFM.   

I have that manual but failed to take a closer look at page 10, you know the one labeled "Voltage Chart". D'ohhhhhhhh.

73
Dan, N8IE

[N8IE]

Well, a little time with the schematic and the problem is fixed.
A wire between V4 and V5 came loose.

After going over the radio I see that I need to replace a few resistors in there!
One has me stumped though, it appears to read as a 100,000 Ohm and is a carbon type. The schematic only shows two such resistors and both are 1/2 watt, this puppy is at least 1 inch in diameter. It connects at pin 4 of T3 and grounds out on V7.

73
Dan, N8IE

[N8IE]

Thanks to the Hallicrafters group, I now know the component in question is a "black beauty" capacitor.
Wow, amazing how much one learns..... now I have a headache! 

73
Dan, N8IE