08-29-2015, 11:16 PM
Good news, bad news
Good news first: The chassis is finally finished, and I applied power for the first time today... Its been on hold while I finished up at my old job - something that sucked my soul dry with 14-hour days, 7 days a week for the last month or so... but finally got back into it today and finished off all the little jobs I've been meaning to do on it to get it done. Photos to follow in an hour or so - I've got to get them off the phone and I'm typing this up while having a coffee and trying to figure out if I'm wrong about the bad news...
Bad news: First thing I noticed was excessive HT voltage (well over 400V), no output (well, quiescent amplifier noise when up close to the speaker... then after a bit a lovely bubbling / gurgling sound from the power transformer... removed the rectifier tube and tried again, same... sigh. Its getting quite hot too. I know, I know... I should have tested it properly before starting but either way I *will* get this going, but it just got more expensive (especially given how scarce these are here and the 240V mains we have meaning I can't just get one from a slightly more abundant location like the US).
Also, the speaker wiring was messed up - at first I thought it had been replaced but I don't think so - but the wiring had been seriously monkeyed with - maybe to hook up an external speaker... so I spent some time figuring that out and sorting it. Its got a little bit of something in the voice coil by the feel of it - but the output tx is fine (although the primary is only about 4.2k not the 7.5k from the schematic) and the field winding is good, and on spec exactly. 9V battery test made (quietish) clicks - so I'll call that a win for now. Its rusty as all heck, so its going to need some love but at least it goes.
Anyway, I'll finish the coffee and think some more...
Steve
Good news first: The chassis is finally finished, and I applied power for the first time today... Its been on hold while I finished up at my old job - something that sucked my soul dry with 14-hour days, 7 days a week for the last month or so... but finally got back into it today and finished off all the little jobs I've been meaning to do on it to get it done. Photos to follow in an hour or so - I've got to get them off the phone and I'm typing this up while having a coffee and trying to figure out if I'm wrong about the bad news... Bad news: First thing I noticed was excessive HT voltage (well over 400V), no output (well, quiescent amplifier noise when up close to the speaker... then after a bit a lovely bubbling / gurgling sound from the power transformer... removed the rectifier tube and tried again, same... sigh. Its getting quite hot too. I know, I know... I should have tested it properly before starting but either way I *will* get this going, but it just got more expensive (especially given how scarce these are here and the 240V mains we have meaning I can't just get one from a slightly more abundant location like the US).Also, the speaker wiring was messed up - at first I thought it had been replaced but I don't think so - but the wiring had been seriously monkeyed with - maybe to hook up an external speaker... so I spent some time figuring that out and sorting it. Its got a little bit of something in the voice coil by the feel of it - but the output tx is fine (although the primary is only about 4.2k not the 7.5k from the schematic) and the field winding is good, and on spec exactly. 9V battery test made (quietish) clicks - so I'll call that a win for now. Its rusty as all heck, so its going to need some love but at least it goes.
Anyway, I'll finish the coffee and think some more...
Steve
There are no personal problems that can't be overcome with the liberal application of high explosives
