I just bought a Watterson on Ebay. Here is the link.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.l2557&rt=nc&nma=true&item=320711132036&si=1nMJH%252B3B3FbX969ju%252Fdk1Gg6i1U%253D&viewitem=&sspagename=STRK%3AMEWNX%3AIT

Can anyone help identify the model number. I looked through all my books with no luck. It may be 500 but I'm not sure. Also, I read that if the serial number is preceded by 25 it should be from Pacific Radio Corp.

Any help would be greatly appreciated.

Thanks.

This seems to be one of those unknown manufactures. There is no model number. I have repaired about 5 of them. All had different name plates. ( General – Universal ) Some have a ballast tube, others like yours has a resistor line cord. The Warwick 542 is as close to any of them for a schematic. It’s a simple TRF set. For replacing the resistor line cord. Mouser electronics sells an 8.2 MFD AC capacitor. Part number 5989-250V8.2-F This in series with a 50 Ohm 10 Watt resistor gives you 68 volts for the heaters. For the duel dial lamps. The sockets can be wired in series. Lift the last tubes heater going to ground. Add the two lamp wires in series with that tubes heater going to ground. Shunt the two dial lamp wires with a 47 Ohm 1 watt resistor. The radio likes this. Slow start saves on tube life.

The Air King 21 is also this same basic set. Here you will find 3 variations.

http://www.nostalgiaair.org/Resources/299/M0000299.htm

:The Air King 21 is also this same basic set. Here you will find 3 variations.
:
:http://www.nostalgiaair.org/Resources/299/M0000299.htm
:

Thanks Warren!