Silvertone 6220 - Videokarma.org TV - Video

Cruiseomatic · #1 04-12-2011, 05:32 AM

Just got one of these couple of days ago. Thing looks like it was stored in a barn, Although it looks very clean under the chassis. Rest needs cleaned and re-finished. Can't find nothing but a fuzzy schematic on it. Old farm radio that runs on batteries. Needs an "AB" pack. If I could get the input voltage I could possibly get a power supply to feed it. If anyone knows something, Please let me know. I'd like to get it running soon and add a light to the dial for night operations.

bob91343 · #2 04-12-2011, 03:13 PM

http://www.antiqueradioschematics.or...tics-sears.htm

For seven bucks they apparently will send you a diagram. The model was made in 1946 it seems. That would, to me at least, imply tubes like 1N5, 1H5, 1S5 and so on. If the filaments are wired in series, add all the voltages to get the A voltage at 50 mA drain. The B voltage is probably either 67.5 or 90 Volts; judge by the ratings on the electrolytic capacitors.

Reece · #3 04-13-2011, 08:39 AM

Here you go. Looks like 90 volts and 1.5 volts. There's a "battery thrift switch." When used on batteries, you'd switch it so the resistors were in line when the batteries were new. Then as they aged and performance dropped off, you'd switch the resistors out so the set would be connected to the battery direct.

http://www.nostalgiaair.org/PagesByM...6/M0017446.pdf

Edit: Looking quickly at the schematic I see two 10mfd @ 150V electrolytics. These are probably dried out and should be replaced. I would bet that this radio was not used much as it's post-war and the power line probably got to the farm not long after. My guess is that if the tube filaments are good, the 'lytics are replaced, and power is applied, this would work. Of course paper caps should be replaced but I'm guessing it would work from the get-go.

electroking · #4 04-13-2011, 12:07 PM

Hi! You may use a power supply, but it is best to get this radio working using
batteries first, especially for the A (1.5 V) filament battery. Also, note that
the two power supplies must have independent grounds, as there is likely to
be a resistor in series with the negative leg of the B battery. This is to provide
negative grid bias to the ouput tube. If you have not yet heard such a radio
in operation, you will be amazed by the instant-on operation of these battery
tubes. Good luck!

bob91343 · #5 04-13-2011, 05:21 PM

That should be a nice sounding radio, and good sensitivity too. I was wrong about the tube lineup; this one uses loktal tubes.

Cruiseomatic · #6 04-20-2011, 08:17 AM

Thought the "elevator" type tuner was froze up since it wouldn't move, Found out the tuner control arm is what is froze up. No signs of major rust, Soaked in WD-40. Nothing. Need to find another one. Haven't even powered it up yet. But since my wife just left it will be a while before this is on my bench.