View Full Version : Hickok 656XC number 2


miniman82
04-18-2014, 08:44 PM
Got the other one today, paid $100 with a box of tubes to boot. This one is in much better condition than the last one, but has a shorted filter cap or something- the mercury vapor rectifier tried to flash over on me when I variac'd it. I'll replace the cap, and pray those precious crystals are still good...

http://videokarma.org/attachment.php?attachmentid=182488&d=1397871777

miniman82
04-19-2014, 10:27 PM
Replaced the multisection cap, got it up to full power. A section of the video phase splitter tube (12AV7) started red plating, found cathode voltage was very low (swung under the grid) because the matched plate/cathode resistors had drifted from 1k down to around 100 ohms. They will need replacing before going any farther.