The PHILCO Phorum

I'm working on a little Detrola model 247 table top job. I understand Detrola manufactured literally hundreds of different radios under their own name and others. This radio is pretty simple, 4 tubes and a ballast. The ballast is badly blackened and has big loose parts rattling around inside, so it's almost 100% likely to be faulty. I can't read the ID on the ballast, but hand written on the chassis it reads. BK55BG. The other tubes are also properly scribed on the chassis and agree with the marks I can read on the tubes so I tend to beleive the ballast really is a BK55BG. I have been unable to locate this particular Detrola model schematic from Nostalgia Air but they do have a schematic which seems to be identical it's listed as Model 208A.

http://www.nostalgiaair.org/PagesByModel...003925.pdf

I have been unable to find a replacement for the Ballast or any cross reference number. I did find some "univeral ballast" replacements at tubes and more :

http://tubesandmore.com/

Any thoughts on finding a replacement. or if I'm on the right track? And no I haven't powered up the little Detrola yet, just gathering my parts list. Thanks, hope someone can steer me in the right direction.

Here are a couple of pic's of this little jem.







May look just another cheap old radio but it was my mother's childhood radio and I know she would get a kick out of hearing it play again. And can anyone figure out why the dial shows a mirror image of its' self below. There doesn't seem to be any difference, or am i missing something obvious.?

Vacuum Tubes, Inc. lists a JFD type B as a universal replacement for your ballast, plus many others. You may want to talk to Jim Cross (the owner) about this?

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His site has a "Contact Us" page.

A year or so ago I had to restore a Detrola for a friend. It had two of those BK55BG ballast tubes. Fortunately they were both still good.

I think your dial scale was just made that way for two reasons: One, for ease of tuning - the top scale is divided by fives (55, 65, 75, etc.) and the bottom one by zeros (60, 70, 80, etc.). Second, just for style's sake.

That ballast appears to be black on purpose. Could be loose cement in the base that is the rattle. I could look it up for pin out but I would guess you should have resistance between 3 of the tube pins. Do not check on a tube tester! If filaments in the set light and the dial lamp lights the ballast is good. If getting a universal replacement, beware that some of the socket pins on the tube socket could have been used as "Tie points" and may cause a problem with a different ballast.

Replacement ballast BK55B arrived, had to pay more than I wanted but apparently these are fairly rare. Haven't tried the radio out as yet, still waiting on my lastest parts order from Just Radios. Seems like I always leave something out and then have to order another $20 worth of parts just to get the $0.49 part I forgot to order on the previous order. At this rate my supply of spare parts is growing rapidly.

Once you build up an inventory shipping costs (and minimum order costs) go down If I need two of a 30 cent part I order 4 or 5. It doesn't take long to build an inventory so that you're not spending so much time and money going back to the well.