Philco model 46-1226 has been my nemesis. It was the first tube radio I ever owned. It had a bad transformer. I tried replacing the transformer, and things went real, real bad.
So, I found a donor radio and now I have a 46-1226 Code 125 chassis. I've recapped it, checked and replaced resistors. I have one open resistor. It is part number 33-1336-4. It is a 300ohm resistor. I jumpered it with a little 1/2 watt and the radio worked, but, of course, the resistor overheated.
Questions -
1. How many watts is part number 33-1336-4? It isn't listed on the parts list because the schematic is for a code 121.
2. Probably a silly question, but Code 125 was put out because Philco changed the speaker to a PM speaker. I have an extra speaker from a code 121. Is there a way to use it, and remove this resistor? I only ask because I have to order the resistor and I'd like to get this thing finished today.
Here is a copy of the code 125 put out by Philco - The resistor I need to replace is number R102
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Hi All;
One possible way for You to get an approximate value is to take out that half watt resistor and put in a meter and see what it reads for amps.. Most DVM's are rated for 10Amps.. That will give you a ballpark figure then go higher than that possibly twice the reading.. It should be Ok long enough for you to get a reading, just don't run it all night..
THANK YOU marty
I would certainly stay with the PM speaker after looking at all the changes necessary to "downgrade" the radio to the EM speaker. Sounds like all you need is the rating on the 300 ohm and your back in business. Do you have a picture of the old 300 ohm? Size would give us a clue. Someone must have an idea. I doubt it is more than 5 watts. That of course is an uneducated guess.
If you have some 1 watt resistors, tack three together (1K ohms) should give you 330 ohms at 3 watts. Hook your meter across them and turn the radio on and measure the voltage drop as indicated. As indicated, don't leave it on forever, just long enough to get the radio playing. Might also at the end of measuring feel how hot the resistors got.
Jerry
Thanks. I might try tacking a few together. I went ahead and ordered a 10w 300ohm. It'll be here in a few days. The only good thing about this radio is that it introduced me to this hobby.
Here is a snapshot of the open resistor. I hope 10 watts is enough...
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That looks like a 7 watt glass resistor. I would definately recheck everything twice if that went out. Anyway, a 10W resistor will do fine.
Thanks Brenda. I was pulling my hair out over this radio. My wife wants this console working, and it's the one radio I haven't been able to fix. It's also the first one we bought. She even refinished the cabinet herself. That was six months ago..For some reason, she really likes this cabinet... This is the second chassis I bought for it, so the pressure is on me...
Everything lit up, but no sound. Not even static. Luckily, there is a nice schematic for this set that has troubleshooting procedures for each section of the chassis. Section 1 failed, and this resistor was the reason why. I never checked it when I was recapping and checking the other resistors. I've learned a lot from this radio.
Have you got any idea why this big resistor would fail? It doesn't appear to be burnt and it's not physically damaged. Everything else in this section seems fine.
PuhPow, in your original post you indicated you have recapped the radio. I'm not certain but it seems like you found the resistor burned, was it burned prior to the recap? I only ask this as if it was you more than likely fixed the problem with new caps. Having had the radio come to life with your 1/2 watt replacement sounds great, the fact that it burned out is not surprising, very underrated.
When you get your new resistor I would bring the radio up on a dim bulb or variac to be safe and monitor on your meter the B+ voltage on either side of the 300 ohm to see if it comes up and holds.
Jerry
Jerry, I assume the resistor was bad before I recapped. The radio was dead before and after recapping. I also found two smaller resistors that were out of spec. I just never checked the three large resistors until I began troubleshooting. I don't know why.. I guess I just assumed they were big and looked ok. Lesson learned.. I will take your advice when I power it up, I have a dim bulb, but I do not have a variac yet.