[MrFixr55]

Hi Philco4Me,
Definitely cut out both caps that are across the power line., remove at least one tube and ohm across the power line with the switch closed. In one direction, you should read infinite. In the other direction, you should read an increasing number which will creep into the megohm region eventually. When cold, tubes will read a rather low value of resistance and as they heat, the resistance increases.

Others mention a "Dim Bulb" tester. This is easily constructed using an octagon box, an extension cord and a ceramic or plastic socket (the type commonly seen in an unfinished basement or garage) to mount to the octagon box. Cut the black wire of the extension cord and attach the wire leading from plug (line) side to the center contact terminal of the socket. Attach the black wire leading to the socket end of the cord to the shell terminal of the socket. The white and green wires should "pass through".

Obtain a 100 Watt Incandescent or halogen light bulb (if you can still find one) and put in the socket. Essentially, what you have done is that you have placed a 100 Watt bulb in series with a 30 Watt radio. If there is a serious short or overcurrent situation, the bulb will light brightly but you won't trip a breaker, burn out the power switch on the radio, etc. If the radio is OK, it may not play when plugged into the dim bulb tester, as it is likely to be getting only about 70 or so percent of the power needed. The following instructions assume that you replaced the filter caps, that they are at least 160WV (200 WV would be better) and you verified filter cap polarity, wiring, etc. In addition, verify that the wiring to the dial lamp, the bulb itself and the socket is not shorted. In the diagram, this shows as being line powered, not low voltage. The parts list describes it as a 117V 7 Watt frosted bulb, so it is likely a white frosted C7 Christmas Tree or Night Light style bulb.

To use the dim bulb tester, start out with all the tubes and EMI caps (Caps #42 and 40) removed. Cap 40 is one of those devices that are between the interlock and chassis ground. Remove that other device that goes from the other pin on the interlock to chassis ground. With these devices out and only the rectifier and filters in circuit, there should be very little draw. If there is high draw, break the connection between the rectifier and everything else. If still a high draw, the rectifier is shorted to chassis.

I have tried several sources for the Code 122 Schematic and am striking out. Unfortunately, not all changes are documented on several Philco sets and this may be one of them. A Philco memo of changes for 1951 and 1952 sets does not list a Code 122 for your set. However,,it does list certain 1952 AC-DC sets with the 122 code where Philco merely added a globar resistor in the heater string, replacing a 50C5 with a 35C5. The resistor has a high resistance when cold and the resistance decreases as the resistor (and string) heat up. If the label of your set shows a 35C5 instead of a 50C5, then you have this resistor. If it is bad, jumper it out and use a 50C5. This may be the only difference.

Hope this helps.

I don't think that there is a difference that if you miss the difference you will blow circuit breakers. This is one of the easier type problems.