Antique Radio upgrades

[graycrait]

Something went haywire in my 1940 Zenith floor model 10S464. Does anyone know of someone who restores these in mid TN? Also and this is a shot in the dark, does anyone know who either rebuilds the "radio" chassis to modern or at least more efficient updated parts including speaker. I like the radio's looks but I am not tied to tradition when it comes to performance. After looking online at the antique radio forums it appears to be a terrible sin to replace the guts of one of these with modern components except where safety is concerned. I have sinned many times and replacing the guts of an antique radio with new components would stand well down on my own list of wrongdoings. I'm willing to take the chance.

Craig in Clarksville

[Garufa]

If you can get it to pick up Radio Mystery Theater your sins will be absolved.

[Mark@Sea]

I can probably rebuild it for you, but I'm in east tennessee.

[TrickyNicky]

Are you looking to just replace the old caps tubes and resistors or swap out the guts for modern PCB boards?
I'd highly advise against going too modern, those olde time radios are getting harder and harder to find and at least IMO are quiet special. I would buy a Bose system before permanently altering anything on it that did not need to be replaced.

Having said that, it's yours and of course you can do with it as you see fit. I would look for a tube amp repairman. They may not be able to help you but may know someone who can.

[graycrait]

Frankly I would be happy if it was safe and worked. Reading on antique radio forums shows that this model needs upgrades to make it safe and reliable. However, what I know about electricity or radios doesn't count as knowledge. If this radio were mint and it isn't, but not bad, and it was updated with appropriate tubes, capacitors, transformer, wiring they sell for about 800.00 plus. I suspect mine, with very minor veneer damage and non op is worth at best a 100.00. This model of Zenith is supposedly very common. My brother and I used to listen to shortwave broadcasts on this when we were kids about 50 years ago.

Quite a bit of info on parts and they are available. Which is good because I need to repair some of the preset switches.

I've got the schematics and plenty of people have rebuilt these but I am not sure about tackling this project. Too bad that someone doesn't rebuild just the radio chassis so that I could buy one, and send them my old one as part of the exchange.


[IMG]http://i862.photobucket.com/albums/ab181/graycrait/Zenith%201005%2010S464/Zenith1005.jpg[/IMG]

[mikegideon]

I'm not an antique radio buff, but worked with a lot of old tube gear in my younger days. Tubes are consumables, even though they may last for decades. Electrolytic capacitors also have a finite life, but it can be decades.

Unless there's an aftermarket gut replacement kit, replacing them will be a mechanical nightmare. It will be easier to fix it if you can get the parts. Chances are good that a properly functioning radio of that vintage will outperform newer solid state guts.

I would track down someone that fixes them, and then decide if it's worth the cost from there. Tube gear is easy if you understand the circuits. It could just be a tube or two that just ran slap out of emission. Since tubes are sort of electromechanical devices, they can fail mechanically and short internally. That can take out components in the surrounding circuitry, usually resistors. In a lot of cases, there will be a visual indication of that.

[mikegideon]

[quote name='graycrait' timestamp='1355062400' post='857183']
Frankly I would be happy if it was safe and worked. Reading on antique radio forums shows that this model needs upgrades to make it safe and reliable. However, what I know about electricity or radios doesn't count as knowledge. If this radio were mint and it isn't, but not bad, and it was updated with appropriate tubes, capacitors, transformer, wiring they sell for about 800.00 plus. I suspect mine, with very minor veneer damage and non op is worth at best a 100.00. This model of Zenith is supposedly very common. My brother and I used to listen to shortwave broadcasts on this when we were kids about 50 years ago.

Quite a bit of info on parts and they are available. Which is good because I need to repair some of the preset switches.

I've got the schematics and plenty of people have rebuilt these but I am not sure about tackling this project. Too bad that someone doesn't rebuild just the radio chassis so that I could buy one, and send them my old one as part of the exchange.


[img]http://i862.photobucket.com/albums/ab181/graycrait/Zenith%201005%2010S464/Zenith1005.jpg[/img]
[/quote]

Question... If it's been around for over 50 years, and obviously hasn't caught on fire, how come it has to be "upgraded" for safety?. I would be happy to help guide you in this if you want to exchange pics and schematics via email. The ugliest part of something like this is tracking down the schematics and parts sources. Can you get all the tubes? Edited December 9, 2012 by mikegideon

[graycrait]

I've got the schematics and I am pretty sure I can get the tubes. Maybe I should just replace the tubes for starters and go from there.

[IMG]http://i862.photobucket.com/albums/ab181/graycrait/Zenith%201005%2010S464/CloseZenith.jpg[/IMG]

[Westwindmike]

When I was a kid, I'd help my Dad take the tubes out of our old radio and take them to the Rexall Drug Store. They had a tube tester there. If they tested bad, they sold new ones in the cabinet below the tester. That was fun!

Best of luck in your repair.

[Guest Lester Weevils]

I don't follow this niche, but maybe it would be easier to find somebody who refurbs classic tube geetar amps, who might have the skill set to do your radio. There is a "fairly big" market for refurbed old geetar amps because some models command pretty high price even as pieces of non functional junk, and highly prized indeed when they look and work as they did straight out of the music store in 1956.

A few years ago met a fella in chatt that was working full-time refurbing old amps, and he was a nut about it. Had big inventory of old-stock but shiny-new looking orange drop capacitors and cloth covered wire and such. He did good work. When he got done the old point-to-point wiring looked better than Fender or Gibson did it the first time out.

The biggest question on that route would be finding such a refurber who knows "enough" about RF circuits.

[TrickyNicky]

Graycrait, let me know what tubes you need. I've got a small box of about 2dozen Misc tubes so I just may have what you need. If I've got them they're yours, if I don't I may be able to point you in the right direction.

[mikegideon]

Ruh Roh... that power transformer has been replaced, and was kind of a hack job. Any time I start on a project like this, I get the Bubba stuff gone first.

First warning... looks like there's some high voltage exposed on the plate caps of those two tubes inside the gold colored shields. Probably won't kill you, but it will make you do your best drill sargent imitation if you get ahold of it.

There will be a bunch of passive components under the chassis. AC power entry is on the left, and looks like it may have been a plug at one point. I'm guessing the other two are speaker and antenna. Looks like the plugs are still intact on them.

I wouldn't just retube it at this point. You probably need to pull the chassis and shoot some pics of the components/wiring. I would try to pull the two plugs, being careful not to put any stress on the wires. You should be able to gently wiggle them and pull them out.

You have to be careful with the tuning dial and front knobs/buttons. There will be some kind of mechanical arrangement driving the tuning dial

[mikegideon]

[quote name='TrickyNicky' timestamp='1355071577' post='857245']
Graycrait, let me know what tubes you need. I've got a small box of about 2dozen Misc tubes so I just may have what you need. If I've got them they're yours, if I don't I may be able to point you in the right direction.
[/quote]

Probably want to go with new tested tubes if they're available. I've wound up chasing my tail with old tube stashes. I probably have a bunch lying around somewhere too, but wouldn't waste my time unless I was really desperate.

[graycrait]

http://www.antiqueradios.com/forums/viewtopic.php?t=139542

This is just one example of a discussion thread on one aspect of a chassis rebuild. It is a foreign language to me.

[Guest Lester Weevils]

When I occasionally worked on tube amps, when the local radio shack quit carrying tubes they gave me their in-store tube tester with the multiple sockets and big "good bad" meter and the flip card tube reference chart. Used it some years but quit doing electronics and gave it away to somebody or t'other. Maybe shoulda kept it, then again maybe shoulda bought a warehouse to keep such junk in.

[graycrait]

I guess the OEM transformer was one of this models shortcomings and someone obviously changed it out. As for the rest of it I will have to cogitate on whether or not I want to spend much money on this. I'm rebuilding an original Bushmaster Hbar right now to suit me and the optic will cost me my monthly gun money, plus my wife of 31 years wants a new stove. I need to do some more research on the radio.

Craig

[mikegideon]

[quote name='graycrait' timestamp='1355072057' post='857253']
[url="http://www.antiqueradios.com/forums/viewtopic.php?t=139542"]http://www.antiquera...ic.php?t=139542[/url]

This is just one example of a discussion thread on one aspect of a chassis rebuild. It is a foreign language to me.
[/quote]

Rebuild is a strong word. Those forums are going to be like gun forums. Some components last forever, and don't have to be replaced. Mica and ceramic capacitors are an example. Resisters as well (in most cases). You can sometimes create more problems than you solve when you "shotgun" components, especially with handwired gear. Best to repair the circuits, and only replace the parts that are likely to fail.

[mikegideon]

[quote name='graycrait' timestamp='1355072408' post='857257']
I guess the OEM transformer was one of this models shortcomings and someone obviously changed it out. As for the rest of it I will have to cogitate on whether or not I want to spend much money on this. I'm rebuilding an original Bushmaster Hbar right now to suit me and the optic will cost me my monthly gun money, plus my wife of 31 years wants a new stove. I need to do some more research on the radio.

Craig
[/quote]

I asumed that you didn't want to spent a ton of money. That's why I'm flapping my jaw instead of telling to to just seek out "Bendover Electronics" for a "rebuilt" chassis.

BTW... I assumed the old power transformer was failure prone. I was just commenting on the lack of craftsmanship. That can extend into other parts of the radio (in my experience). Poorly chosen parts substitutions are more common than you may think.

Edited December 9, 2012 by mikegideon

[Guest Lester Weevils]

Were the multi-stage superhet tube circuits (in proper adjustment) more selective than today's run-of-the-mill consumer radios? Or is the spectrum just more crowded nowadays? Most modern consumer radios below $80 or $100 don't seem selective worth a darn, and sometimes a brand-new name brand clock radio or boombox will pick up certain strong stations several places on the dial, wiping out all the weak stations. I've even seen this on Sony portables.

I just don't recall it being such a problem long ago, but maybe the memory is failing. Edited December 9, 2012 by Lester Weevils