Stromberg-Carlson 561
manufactured in Toronto, Ont. Canada
ca. 1947 s/n 56121548
Once I got it home, I discovered that the reception was much better than at the store, which was half underground and had lots of fluorescent lighting.
The first thing I did was take the chassis out, and remove the grille cloth and dial cover. I washed the cabinet in the kitchen sink using warm water and a bit of dish soap. I had to use a toothbrush and a toothpick on the crevices and grooves. What I had thought was a solid dark brown bakelite turned out to have a pattern, like tortoiseshell or woodgrain. Another fortunate thing was that there were no decals to be woried about, which made it that much easier.
After a bit of research on the internet, I went out and got some TurtleWax brand "Polishing Compound and Scratch Remover". I picked the "soft and creamy" variety, with the finer abrasive. The flat areas were pretty easy to do, but the stepped L-shaped areas on the top and the grooves around the front and left required some sophisticated hardware. I used a Popsicle stick to work a soft rag into the bottom and sides of the grooves, constantly pulling the rag so as to be using a fresh area of the rag, and a fresh bit of rubbing compound as I moved along. If I was to do it now, I would have finished up with rottenstone polishing compound.
Two days later, I was ready to wax it. I applied Trewax (carnauba wax), a few square inches at a time. Again I had use the trick with the stick in a rag to buff out the grooves. I had lots of time.
I was able to get a schematic and service data from JustRadios
- Canadian Antique Radio Schematics so I can give it a good tuneup later.
Underside of chassis. The oversized AC cord with the yellow crimp connectors has since been replaced. The wiring was in good shape, not too brittle or worn anywhere. I have yet to go over the circuit and see if the voltages are all what they should be, check the capacitors, and so on. |
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Top of chassis.
I didn't fiddle around too much in here, except to take out the tubes and wipe them off, brushed and vacuumed the chassis and the tuning capacitors, and to replace the pilot lamp. Imagine my surprise when I discovered that you could buy Type 47 bulbs at the neartest Radio Shack store! Some day I'll find a good way to straighten out the back cover that won't damage the stickers |
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As you can see here, the decal (or screen printing?) had started to
peel from the dial face. I'm not going to touch that, for fear of losing
more of it.
The next time I have the chassis out, I'm going to straighten up the dial cover. (Again!) |
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The yellow sticker is the tube placement chart.
The red one has the dire warning against operating a receiver without a license from the Ministery of Transport. This requirement was ended in 1953. I hope to repair the broken hole for the screw (missing) in the upper left of the cabinet. |
IF frequency | 460 kHz |
Line Volts | 105-125 V
DC to 60 Hz ("AC/DC") |
Tube complement: | |
Rectifier | 35Z5GT |
RF Amplifier | 12SK7 |
Mod Oscillator | 12SA7 |
IF Amplifier | 12SK7 |
Demod/AVC/Audio Amp | 12SQ7 |
Output Amplifier | 35L6GT |
Good News! I won an auction on eBay which consisted of three parts sets
two model 561s and one model 761. One of the 561 chassis had a dial face in
better shape than my first one (above) and the other had an older style dial
face (see below, left), so now I'll end up with a complementary pair.
Both have exactly the same dial pointer, the same as on the model
761.
"Older style" dial face. Note the use of upper and lower-case letters in the name, typical of the logos on the pre-war Stromberg-Carlson sets. The typeface looks something like a bold Garamond. The frame, outside the brown, is black. Part Number: P-34500 - MADE IN U S AMERICA |
Newer style dial face, which I call the "yellow hand" style. The typeface in the logo is more of a sans serif calligraphic style, all in upper case. The background is more of a burgundy than brown, and the frame is light-coloured. Part Number: P33121C |
This introduces a mystery. Which ones have which dial face? Is there some serial number after which they changed the dial face graphics? I've started to collect serial numbers of various sets that I've seen on eBay and other sources. More recently I've been asking owners to check the city of manufacture, just in case there were some made elsewhere besides Toronto.
Serial Number | Dial Face | City |
56110507 | old style | Toronto |
56114863 | yellow hand | sticker with city of manufacture missing, but there is a small sticker for a service shop or store with a Toronto address |
56118221 | old style | Toronto |
56119230 |
old style | (unknown) |
56121548 |
yellow hand | Toronto |
58109318 | yellow hand | (unknown) |
As you can see, #56114863 appears to break the pattern, so i don't know what's going on.
[ 5612874 - yellow hand. This number was sent to me, but it doesn't seem to have have enough digits in itso I'm leaving it out of the list.]
If you have a model 561, please email me with the serial number, city of manufacture, and which dial face ("old style" or "yellow hand") it has. If you can see it, the part number in the lower left-hand corner would be nice too. It's possible that some may even have the same dial face as the one on my model 761, shown below:
Note that it has the green graphics like on the "old style" 561, but the sans serif typeface like on the "yellow hand" version.