I bought this at a garage sale for $30. The patent numbers on the back make it no older than 1938. It would be neat to have it operational but I think it's well worth that price just as a testament to the incredible work people did by hand back then.
The power cord insulation is rotting so that is a no brainer.
There is a pile of dark wax under the power transformer that I have been told indicates that the transformer was overheated and should be checked for shorts. - Do I need to desolder the secondaries to check this?
How should apply power? Variac? Someone mentioned a light bulb in series. Does this have similar affect as a variac?
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The power cord insulation is rotting so that is a no brainer.
There is a pile of dark wax under the power transformer that I have been told indicates that the transformer was overheated and should be checked for shorts. - Do I need to desolder the secondaries to check this?
How should apply power? Variac? Someone mentioned a light bulb in series. Does this have similar affect as a variac?
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A low wattage light bulb in series with primary can be used to check for a short in the power transformer if all secondaries are taped off. There should be very little glow from the bulb, a bright glow indicates a short. A slow charge by either a Variac or series resistance with the primary is a good call on any equipment that has sat for a while. Also note that ALL the wiring inside should carefully be checked for breakdown of insulation and replaced as needed before any attempt to fire it up. Good luck and be safe
Hi,
There are probably some elco's in there that need to be reformed. There's plenty of information on the web about that. Using a variac is a possibility, beter get them out there and reform them one by one.
Checking for a short is probably possible with a volt-measuring device (don't know the english word). Just apply it to one main and one secundary and check all possibilities.
Don't know how tubes behave after such a time...
Remco Poelstra
There are probably some elco's in there that need to be reformed. There's plenty of information on the web about that. Using a variac is a possibility, beter get them out there and reform them one by one.
Checking for a short is probably possible with a volt-measuring device (don't know the english word). Just apply it to one main and one secundary and check all possibilities.
Don't know how tubes behave after such a time...
Remco Poelstra
I think the worst is that it catches fire because an elco or something 'explodes'. I don't think it will give a big bang, but you asked for the worst. It will probably just get messy.
I don't have experience with those wax-paper caps colt45 mentions, but they sound like they burn wel.
Remco Poelstra
I don't have experience with those wax-paper caps colt45 mentions, but they sound like they burn wel
.Remco Poelstra
At least it looks like a standard superhet with an energised speaker - there shouldn't be any unusual or 'patent' circuitry which could be difficult to follow.
I have had a set where the rectifier had an internal short causing the mains tranny to overheat and start a fire - on the outside the cabinet looked fine, but inside half the circuitry, the mains tranny and the speaker had gone to meet their maker...
I have had a set where the rectifier had an internal short causing the mains tranny to overheat and start a fire - on the outside the cabinet looked fine, but inside half the circuitry, the mains tranny and the speaker had gone to meet their maker...
Get your self over to http://www.vintage-radio.com/index.shtml
Lot's of good advice for reviving an old radio, there's a Forum also to help with questions.........
Lot's of good advice for reviving an old radio, there's a Forum also to help with questions.........
I wouldn't be surprised if that insuation has been eaten away by cockeroaches or vermin in general, you're taking a pretty nice risk also by simply firing it up with that amount of heat damage and age thrown in too...
That aerovox capacitor looks brand new don't it? ;P
Amazing how deceiving age can be, take a look underneath the top-end of the Aerovox capacitor near the post, looks like it has splurted all it's wax and guts over the top of the radio while it was still molten hot!
Also those pure white-grey ones have a plastic tube if I remember , just above the capacitor in question. I have some here that look brand apsolutley new and meh they're gone!
Also a note on replacing so many things, TAKE IT SLOW! really damn slow, make sure you take a few pictures as to how it all looks, and follow them to the T, put it all back in the way it was supposed to or you'll find the AM receiving or Amplifier section has some flaw or huge hum or buzz/noise from somewhere where you've moved a capacitor 5 cm from it's original position.
Theres no need to rush things, you have a Transistor radio around somewhere? listen to that and ward off the temptation of powering it up early in the process of replacing
It's waited 50+ years, it can wait a few more weeks...
That aerovox capacitor looks brand new don't it? ;P
Amazing how deceiving age can be, take a look underneath the top-end of the Aerovox capacitor near the post, looks like it has splurted all it's wax and guts over the top of the radio while it was still molten hot!
Also those pure white-grey ones have a plastic tube if I remember , just above the capacitor in question. I have some here that look brand apsolutley new and meh they're gone!
Also a note on replacing so many things, TAKE IT SLOW! really damn slow, make sure you take a few pictures as to how it all looks, and follow them to the T, put it all back in the way it was supposed to or you'll find the AM receiving or Amplifier section has some flaw or huge hum or buzz/noise from somewhere where you've moved a capacitor 5 cm from it's original position.
Theres no need to rush things, you have a Transistor radio around somewhere? listen to that and ward off the temptation of powering it up early in the process of replacing
It's waited 50+ years, it can wait a few more weeks...
If I were you, I would plug it in ever so briefly to check that it actually works (ie 10 seconds max, see if you can get sound or even better a station!) Be ready to switch the thing off if it does go bang.
Then if it does go, replace all capacitors in the thing. Replace all resistors that have drifted outside their values. ( high values like 100k seem to drift the most)
With that burned looking power tranny, I am not so confident... it may be fubared
Then if it does go, replace all capacitors in the thing. Replace all resistors that have drifted outside their values. ( high values like 100k seem to drift the most)
With that burned looking power tranny, I am not so confident... it may be fubared
Yeah, some of those capacitors look like they are brand new. The radio is a time capsule of sorts and I almost don't want to change anything about it.
Are the resistor markings the same used today? They look hand painted. I'm not sure if I could reliably discover their original values without a schematic.
If I need to restore to working condition, I'll take my time. It would be an extremely ambitious project for me.
What types of broadcasts can I find on shortwave? Is there anything good on AM anymore?
Are the resistor markings the same used today? They look hand painted. I'm not sure if I could reliably discover their original values without a schematic.
If I need to restore to working condition, I'll take my time. It would be an extremely ambitious project for me.
What types of broadcasts can I find on shortwave? Is there anything good on AM anymore?
I fell into this trap sometime ago of fusing the neibourhood supply .....You haven't mentioned about......make dammned sure one side of the mains isn't connected to the chassis......aahhh.. and don't plonk a scope earth on it when it's switched on......this B+ technique was a pretty common development using simple half wave rectifier and series dropper for the high voltage heater chain.
You might have an LS chassis with energised electromagnet as hum buck........part of the B+ smoothing circuit..... in otherwords it's alive.........and kicking....
Use isolating tranny! please
......All this makes modern stuff a breeze......
rich
You might have an LS chassis with energised electromagnet as hum buck........part of the B+ smoothing circuit..... in otherwords it's alive.........and kicking....
Use isolating tranny! please
......All this makes modern stuff a breeze......
rich
Probably not. They used to use "Body - Tip - Spot" in place of First, Second, and Third rings. See this vintage site for details. All resistors were 20% (or worse).
Haven't looked at SW for years!
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