[Heathkit] SB-102

[Drew P. via Heathkit]

Daniel Yoder wrote:

"I just got my Tech ticket a few weeks ago and own a SB-102. I want to
see if I can fire this up soon. I am in the middle of rebuilding the HP-23A
and I want to get on 10 meters SSB.
I have another HP-23A that I have been cooking with my variac. At 70 VAC
input to the primaries I am getting close to 590 HV 220 LV and the 12 vac
is reading 22 and the 6 vac is reading 14, why is this AC so high?"

Make sure you are measuring voltage between the correct connector pins. Two of the pins have AC line voltage - probing one of these when trying to measure heater voltage might cause the reading you describe.

"I would like to try out just the receiver section of the transceiver with
this supply. Should i still use the variac when I connect the SB or should
I just go for it."

You DC readings look correct for the input voltage you mentioned.  Check the heater voltage again. 

"How can I set the controls so I am not i transmit mode
and the finals are idling."

PTT button on mic not  depressed.  Key up.  "Mode" not in "Tune".  Finals will then draw no current.

"Since I have 20 tubes I assume that the filament currents will be pretty high. Does it hurt the tubes to run them via a variac?"

Heaters are best run at rated voltage plus or minus 5%, but will tolerate excursions a bit outside of this range.

Drew