Truetone D 2237B ....SMD?

[electra225]

The schematic I have is Beitmans from 1952. I need the Sams folder for this chassis, Sams 182, Folder 15. That is my next step. I need good alignment instructions. The set will play like a house on fire if I hold onto the antenna or if I connect the external antenna. I believe I fixed the SMD. I put the old 33K ohm resistor back in, drifted or no, got the radio playing. So much for doing it right. I learned a lot in this project. First, don't mess with anything else like the alignment or adding any new parts. Do the SMD repair, make sure it is right, that your wiring is right. After that, you can recap or change resistors and that. I am fixing supper right now, and have pictures to post. More on this later....

[electra225]

Yessir, I chased my tail because I was too stubborn to believe what not one, but THREE VTVM's were trying to tell me. I had 87 VDC on one end of that 33K ohm resistor, none on the other end. It checked good, still does. It simply broke down under high voltage, if you want to call 87 VDC high voltage. It seems to me like this radio chassis takes a long time to develop B+. The radio plays well if I put my hand near the loop antenna or if I connect an external antenna. I don't remember ever aligning it, and it needs a good alignment. I need to find Sams 182, folder 15. The schematic I have is Beitman's from 1952 and it doesn't include resistance measurements or alignment instructions. That is my next stop. I learned a lot and made a lot of mistakes on this project.

SMD in the first IF transformer

[electra225]

I may have located a couple new IF transformers for this set. The second IF I need for sure. I will keep the other one for a spare. SMD repair is not always successful.

[William]

Good news, are they close by?

Bill

[electra225]

Ohio, IIRC. One of my recommended vendors. I haven't gotten them yet, so I shall withhold praise for a more appropriate time.

[electra225]

I may not need new IF transformers. I had really three issues yet with this radio that I needed to get sorted. The first one is that it needs a good alignment. I haven't found instructions yet, so I'll order a Sams from the Schematic man. Next, I couldn't get either IF transformer to peak. The adjustment essentially did nothing. I got desperate and a little annoyed that nothing I did seemed to work. I started pulling tubes and running them thru the tester yet again. One of the 12BA6 tubes, used as the IF amp, was actually a 12AD6. This is a converter tube used in those 12-volt hybrid car radios in the late 1950's. The plate is made to run on 12 volts. The pinout on the 12BA6 and the 12AD6 is really similar, the difference being that pins 2 and 7 are reversed, That tube was the reason the IF transformers wouldn't peak. The only way for that tube to be there was that I put it there. When and why, still unknown. The other issue I had was an intermittent scratchy, hashy, irritating noise in the audio. When I put the tubes back in after testing them, I put a spritz of PB Blaster on each tube pin, then wiggled them around real well. This seems to have taken care of the mystery noise. Time will tell on this one. It would appear after the set ran for a couple hours. I think after I do a good alignment, this old set will be back to normal.

[William]

That is good news, and the wrong tube. It is so easy to overlook something that is right in front of you. Don't ask me how I know this.

Bill