Can't locate a schematic/service manual for a Trutone D3612, 12 transistor AM receiver. I checked SAMS, Beitmans, etc. Any ideas? Ken

Hi Ken,

I think you mean a Truetone DC3612. It's in Sam'S TSM-63.
https://samswebsite.com/en/photofact/se ... del/DC3612


See here:
http://oi50.tinypic.com/302qlnl.jpg
http://oi47.tinypic.com/wbqohi.jpg
http://oi45.tinypic.com/1zv496h.jpg
http://oi46.tinypic.com/317bk01.jpg

~ Mitch ~

Mitch- you're right! It was a DC3612. I didn't write it down and went from memory. (Won't do that again!) Mitch thank you for the SAMS pages on this radio. It's going to help me a lot. As you can see from the picture, there's a lot crammed onto that board and troubleshooting without a schematic and layout would be a bear. That audio section of 8 transistors would be a real pain to figure out and trace through without a schematic. Again, I'm very grateful for your help. Ken

You're welcome Ken! - Post a photo or two of your radio.
Preferably before, during and after restoration.
I think everyone here likes to see those, (at least I do).

~ Mitch ~

Good Idea Mitch. It may be awhile though. First I have to get it operating. Then phase II, case restoration. Externally, it needs a lot of work. Cleaning, painting, scratch removal, removing grill dents, etc. One interesting thing about this radio is that all the resistors are radially leaded. I'll put that picture in soon as well as anything else unusual.
This may be a little OT but in my collection, there's some unique feature of most of my radios. It's like "every radio has a story". For instance, I have an RCA radio where the speaker is mounted on the back and the sound is projected out of the back of the case. Another is a GE radio with the reed speaker and PC traces on the component side of the board only. Another example is a Motorola radio that has a large ferrite bar antenna that is really sensitive. Another is a multiple transistor set with 14 transistors from the "transistor wars". You get the idea. Ken

Mitch, I got the radio working. Your SAMS helped a lot. Saved me some time. The problem was two open electrolytics and the oscillator vanes in the variable capacitor were shorted to ground. It was an open air type so I just bent back the touching vanes. Thanks again for your help. Ken

Glad to hear you got it going there Ken.... always glad to help.

~ Mitch ~

Hey Ken---an interesting radio ! No audio transformers... How's the sound quality & volume with that transistor-heavy "ITL" & OTL audio circuit ?

John

Hi John. Surprisingly the audio is not exceoptionally loud. On strong stations, it's a little louder that a typical 6 transistor transformer coupled set . The fidelity is pretty good. This radio is unique with 8 transistors in the audio section. However 2 are for emmiter followers just for impedance matching. I replaced all the electrolytics and the audio transistors all seem to have correct voltages. BTW, one other problem that I came across but forgot to mention was a high Vf (~0.8V) on the detector diode. I replaced it with a 1N34 and it made a big difference. Ken