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Stromberg Carlson Console Radio
I finally got some decent pics taken of a radio I picked up at an auction a couple of months ago. It needs a lot of TLC, but I think it looks nice. Does it look familiar to anyone? Any guess of the vintage?
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#2
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Another pic....
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#3
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one more....
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#4
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Benjamin- Nice score !! Would be nice if we had the model #- but offhand, I'd say it's late '30s-early '40s. If you've read several of the old radio & TV threads, I'll assume you know not to plug it in & turn it on. Looks like it has an eye tube-that's kinda neat. Go over the cabinet w/something like Murphy's Oil Soap or Scott's Liquid Gold, & then Old English, if the finish isn't too bad. Be careful cleaning the dial-painful personal experience has shown sometimes the markings are DEFINATELY "Windex-soluble". If you're not too good working on these things yrself, there are several AKers who repair old radios & TVs. Good luck !!-Sandy G.
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#5
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Thanks for the advice Sandy. I've cleaned it up with iquid gold and it looks nice. The finish is in great shape, bar a few scratches. The faceplate is cool. It looks like its backed with felt.
As for plugging it in, I couldn't even if I wanted too, the power cord is totally rotted out. What I liked about it was that it still had all its buttons and the original knobs. If it nver works again, it'll still be a nice piece of furniture. |
Audiokarma |
#6
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I'm guessing somewhere between 1935-1941.
There sure are a lot of labels on the back of the chassis that look to be in good condition. I'm surprised there's no helpful info there... especially on that metal plate that's almost in the middle. Sometimes chassis numbers are there, but do not label it. I've had chassis numbers staring me right in the face, but did not realize it was a number of significance. The chassis looks pretty clean. Probably not too many caps under there to replace. Should be an easy set to get going again.
__________________
Charlie Trahan He who dies with the most toys still dies. |
#7
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I had an H-420 that I sold on eBay - this one looks like the console version. 1940 model. Picture on my page - http://www.audiophool.cjb.net/MadeInRoch.html
List the tubes and I can probably find the exact model and find you a schematic. |
#8
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Yes, mine does look very similar to your H-420. The only difference that I see from a quick glance is my transformer is much larger. But then again, the driver is atleast a 12".
The numbers I've located are these: On the paper work its stamped 992L/100 And on the tuner is stamped FK49 The plate only has the serial # AC volts cycles Max watts I'm nervous to pull the tuner out..i don't want to break the dials. |
#9
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Antique radios
Congrats on your find! It looks gorgeous.
If you're interested in learning more about antique tube radios, both the electrical repair and restoration, and also cabinet refinishing, the best source on the net is: http://www.antiqueradios.com/. Great group, extremely knowledgeable, and very helpful and friendly. Just like another group we know! Stop by and take a look. Uuuummmm, it does make it look better, but probably wouldn't have done the Scott's Liquid Gold thing. No permanent harm done, you're just going to have some extra work to do when you get around to the full job on the cabinet. Right on about the dial lettering, though. Never put any liquid, not even water, on the silkscreened side. Just your breath and some lens cleaning tissue, and then start very slow and careful in an inconspicuous spot. Believe me, I learned my lesson the hard way, too. You don't want to be looking for another dial glass for that radio. Have fun! Clay |
#10
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The schematic for the 420H is here: http://www.nostalgiaair.org/schemati..._SCT_11-13.gif
It's pretty fuzzy though. The (H) is the tabletop cabinet. There are more pages on this model - change the "13" in the above URL to "12" to go back a page, "14" to go ahead etc. Or just chop it off after /SCT/ to see ALL Stromberg numbers. The tubes in the 420 are 6A8, 6K7, 6SQ7, 6H6, 6F6, 6AF6, and 80. If the tubes in yours are the same it's probably the same model - there were several similar ones with different tubes. But could be a similar Canadian built model too. The larger transformer is probably a 25 Hz model. Common in areas that got power from Niagra Falls. Will run REALLY cool on todays 60 Hz. |
Audiokarma |
#11
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I had some time to take a look and this is what i found on the back plate:
Two- 6V6-G Two- 6SQ7 and IF amp 6K7 Rect. 5Y46 Tun6AF6G-IND DEM A.V.C. 6H6 Thanks for all the links. One more week to go on a teachers course I'm finishing up and then I really get started with all my projects. I may even get some of my basement finished as its now going on 2 years since I started that project! |
#12
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This looks like model 435, or a later variation. I think you missed one tube number - there's a mixer tube (6A8?). Can't read the schematic very well, but it's here: http://www.nostalgiaair.org/schemati..._SCT_11-25.gif
The 5Y4G tube is hard to find - hope it's good! |
#13
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Speaker info
Benjamin,
I looked at the pic of the back of your Stromberg just now and saw what looks like an octal plug and socket, with a rather long cable going back to the speaker. This leads me to believe your set has an electrostatic (as opposed to permanent magnet or PM) speaker system. (I once had a Magnavox AM/FM receiver with such an arrangement.) The electrostatic speakers used a field coil which was also part of the power supply (as a choke), and were common in console radios of the '30s and '40s. This also leads me to believe your SC was made some time during that era, as PM speakers did not appear in radios until the late '40s-early '50s. If you have (or have access to) a Variac, which is a variable-voltage autotransformer, I would use it between your set and the AC line if you have doubts as to whether the radio works. Start at zero, then bring up the voltage very slowly, using the control on the front of the Variac, watching for any signs of short circuits, e. g. smoke, sparks, etc. If you can increase the voltage to 120 VAC without problems, you can continue with your testing. Lacking a Variac, you can power up the radio through a 100-watt bulb, which will act as a current limiter. If the bulb glows dimly when you plug the set in and turn it on, the power supply is likely OK. If, however, the bulb lights brightly (or immediately burns out with a bright white flash) as soon as you turn the radio on or plug it in, there is a short which must be corrected before further testing is conducted. I have a 1951 Zenith radio with a pilot light on the front of the cabinet; this lamp will burn out immediately if the filter cap or rectifier tube is shorted (or if the filter is deformed for any reason) when the set is turned on. (Note as well that if the radio is operated with an open pilot light, the filaments of the tubes will be overloaded, as the pilot light normally takes up part of the filament voltage.) Many AC/DC radios which had pilot lights wired across the rectifier tube (35W4, 35Z5, etc.) would exhibit similar behavior if the tube or the filter cap were shorted as well. Another tipoff to a shorted filter capacitor is if your radio blows a fuse or trips a circuit breaker on the house circuits as soon as it is turned on (or as soon as you plug it in); the reason is that the filter cap is wired directly across the AC line. If the filter shorts, it will put a direct short across the line which, of course, will blow the fuse or kick out the breaker immediately (the radio does not have to be turned on). In a set this old, I would replace the capacitors on general principles, as there are certainly a few leaky or even shorted ones under the chassis. Hope this helps. Best of luck and very kind regards,
__________________
Jeff, WB8NHV Collecting, restoring and enjoying vintage Zenith radios since 2002 Zenith. Gone, but not forgotten. Last edited by Jeffhs; 02-21-2004 at 12:39 PM. |
#14
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electroststic vs electrodynamic speakers
Jeffhs, All,
Just a technical point of correction. The field coil speakers are often correctly called just that. They are also known as "electrodynamic' speakers as opposed to permanent magnet 'dynamic' speakers. Jeffhs used the term electrostatic loudspeaker. That is an entirely different animal which resembles an air dielectric high voltage capacitor. The diaphragm that produces the sound is conductive and is pushed and pulled between two outer perforated conductive panels by electrostatic forces created by a high voltage power supply and modulated by the audio signal which is increased in voltage with a special step-up transformer. |
#15
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Re: electroststic vs electrodynamic speakers
Quote:
I stand corrected, Rob--thanks. Your description of these units rings a bell, as there is an electrostatic tweeter in my Zenith K-731 AM-FM radio (no wonder the set sounds so good). I posted a question about that unit last year in this forum; the reply stated pretty much the same thing as you said here, namely, that the electrostatic tweeters operated directly from B+. In 30+ years of working with electronics, I had never seen an electrostatic tweeter in any kind of audio or radio equipment until I saw the one in my Zenith. Had me scratching my head for awhile--this blue box with a cable hanging from it, connected to a terminal strip on the chassis. Oh well, at least now I'll know what I'm looking at next time I see one of these things!
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Jeff, WB8NHV Collecting, restoring and enjoying vintage Zenith radios since 2002 Zenith. Gone, but not forgotten. |
Audiokarma |
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