Hi,
My grandfather has an old Stewart-Warner model 208BK stand up radio, and he say's the transformer blew out years ago. I would like to get him a replacement one for Christmas, but "Googleing" this just seems very uneventfull. Can anyone point me in the right direction?

Thank You.

:Hi,
:My grandfather has an old Stewart-Warner model 208BK stand up radio, and he say's the transformer blew out years ago. I would like to get him a replacement one for Christmas, but "Googleing" this just seems very uneventfull. Can anyone point me in the right direction?
:
:Thank You.

Mark,

First of all, you need to make sure it is truly the transformer and not something else. Often people blame the transformer when it could simply be a tube, switch, etc. Transformers are generally expensive and sometimes hard to replace - you wouldn't want to go to the trouble and expense unless absolutely necessary. Also, with most old radios, it likely needs other repairs as well - like replacing faulty capacitors, tubes, wiring, etc. From your question it seems like you are not very familiar with radio repair. Particularly since this radio has sentimental value and you wouldn't want to goof it up, I'd recommend you find someone locally who can repair it and ask if you can watch. Perhaps you'll get the radio bug and learn to repair them. Give us a location and perhaps someone on this forum can recommend someone to you.

www.tubesandmore.com and www.radiodaze.com both sell transformers. If you know a bit about electricity, then I recommend that you do the following:

Give us the DC resistances of the various windings. You can view a schematic of the radio in the Resources section of this web site. Once you determine what the various windings are, measure them with an ohmmeter with all of the tubes removed.

Once we have the DC resistances, we will be able to tell you whether you should proceed further or not.

Further testing and repairing includes plugging in the radio with all tubes removed, with a light bulb in series with the line cord....and then without the light bulb, checking transformer voltages, checking capacitors for leaks and shorts (which will give clues about the problem), replacing all capacitors (this isn't as expensive or difficult as it seems...it's really quite cheap, and is a wise thing to do...I like to rebuild the old capacitors with new units inside to keep everything looking original, but you don't have to go that far if you don't want to at the moment), replacing heavily drifted or open resistors, and various other devices, if necessary (drifted or open resistors don't often cause trouble, but can sometimes indicate trouble elsewhere), and finally operating the radio with all of the tubes in place.

Even if you don't understand a lot about electronics, all of the above should be fairly easy for you to perform, and shouldn't take too much time. Transformers and some tubes can be expensive, though most other parts are inexpensive. You can get a good ohm meter from Radio Shack for under $20. It will be very accurate, and will be able to run many necessary tests in the radio.

T.

Thank you both very much, I will more closely look at it next time I'm there.

Agree with Thomas to a point - there's often no better way to learn to swim than to just dive in - but make sure you have a 'lifeguard' nearby and that you have done some homework on radio repair. Changing a transformer isn't as simple as replacing a lightbulb - and there are some potential dangers - ie., electrocution. Another problem here is that you're wanting this by Christmas - a tall order for a newbie. That's a major reason I'd recommend repair by someone with experience. My other suggestion would be to buy yourself a modest tube radio in relatively good shape (and no family ties) at a flea market to tinker with and work up to the bigger stuff as you learn. Sometimes we (I'm guilty too)on these forums tend forget experience levels when making suggestions.

Well, with our help, you should be able to blindly finish this by Christmas. You might not know what you are doing when you are finished, but you will have the result you want. Diving in and doing yourself is more fun, and you learn more (slowly), but it can also cause you much trouble (and expense).

If the power transformer is in fact blown, you want to find what blew it (if it didn't fail on its own). If it is not blown, you want to find what is overloading it, or what else (field coil, resistor, etc.), is causing the problem. This should be very straight forward for you, even if you don't know what you are doing. Start where I said, and we'll work from there. Replacing all of the capacitors is recommended because it will insure reliable operation.

T.