04-09-2016, 10:13 AM
Tried to put it in the cabinet yesterday, stopped playing. More bad connections. Tookit out. What I thought before to be some tube socket issue (twist the chassis or touch a tube, playing stops) turned out to be one bad solder on the osc coil a wire looped over another, floded with solder but moving freely) abd then wgen I touched another wire on another coil it just came off, so reworked that one too.
Seems to cure the " don't touch me" chassis problem.
Not putting it back to cabinet - have no knobs and the shafts are not protruding requiring the knobs with "necks" otherwise cannot tune.
The field coil wire was on its last leg where it goes in the coil, had to pour hot glue over.
Works fine after that. Reception is good across the dial.
PS. Terry, I rechecked the 25Z5, it is in fact strong, both halves show better than middle of the green zone. I am tempted to shunt the cap that is the B+ (the other one is strictly the field coil) with a reversed diode to keep it from repolarising but it seems it stopped going into -25V and now is about -1V.
PPS. Tried that original 43 with HK short. It works but the radio hums VERY loudly. Two other tubes, one with the short that disappeared (tests good now) and one that came today, no short upon the test, both have zero hum.
So, as I expected, short does affect things in radios that have no separate winding for the heaters (like here, ACDC with filament string).
Possibly might work fine in transformered radios but...I doubt 25V heater tubes were used in those.
Seems to cure the " don't touch me" chassis problem.
Not putting it back to cabinet - have no knobs and the shafts are not protruding requiring the knobs with "necks" otherwise cannot tune.
The field coil wire was on its last leg where it goes in the coil, had to pour hot glue over.
Works fine after that. Reception is good across the dial.
PS. Terry, I rechecked the 25Z5, it is in fact strong, both halves show better than middle of the green zone. I am tempted to shunt the cap that is the B+ (the other one is strictly the field coil) with a reversed diode to keep it from repolarising but it seems it stopped going into -25V and now is about -1V.
PPS. Tried that original 43 with HK short. It works but the radio hums VERY loudly. Two other tubes, one with the short that disappeared (tests good now) and one that came today, no short upon the test, both have zero hum.
So, as I expected, short does affect things in radios that have no separate winding for the heaters (like here, ACDC with filament string).
Possibly might work fine in transformered radios but...I doubt 25V heater tubes were used in those.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
