Old transistor radio

Discussion in 'General Electronics Chat' started by Magoo Lew, Jul 31, 2015.

  1. Magoo Lew

    Thread Starter New Member

    Jul 31, 2015
    3
    0
    Hi guys,

    I was looking in my electronics shed for some parts today and I came across an old AM radio chassis. I have no idea as to who made it. It doesn't have any type of case, just the circuit board. It didn't have a speaker connected, but I was able to figure out where to solder it. I turned it on, and it works, but I can barely hear it. I soldered on an 8 Ohm speaker. If I changed it to a 4 Ohm speaker, would I get more volume or would I have to have something higher than 8 Ohms? Mostly I work on old tube Geiger counters and don't know much about radios.
     
  2. #12

    Expert

    Nov 30, 2010
    16,268
    6,780
    There is no telling from here what kind of speaker that radio was designed for, and you can see it better than we can! Personally, I wouldn't fix it if I was going to own it after I was done, however...if you give more details, you might get some actual help.

    Does it plug into the wall outlet? Does it have vacuum tubes? Does it have a brand name? Can you find any code dates? Would you know how to read code dates? Are any capacitors drooling their guts out? Does it have an output transformer? Does it have more than one big transistor on a heat sink? etc.
     
    Last edited: Jul 31, 2015
  3. BR-549

    Well-Known Member

    Sep 22, 2013
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    Does it have an antenna?
     
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  4. absf

    Senior Member

    Dec 29, 2010
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    If It has a circuit board (PCB), I would say it is not that old.
    Why not just take a photo (best be < 500KB) and post it here so we can help?
    Should be fun to fix it...

    Allen
     
  5. #12

    Expert

    Nov 30, 2010
    16,268
    6,780
    I fixed a thousand TVs with circuit boards and vacuum tubes. Pre-circuit board was a very long time ago.

    I just noticed the title...transistor radio. Might be as early as the late 1950's.
     
    Last edited: Aug 1, 2015
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  6. Magoo Lew

    Thread Starter New Member

    Jul 31, 2015
    3
    0
    All I can say is that it is a transistor radio. There is no name or case to it. I don't even remember where I got it. I just found it looking for some other parts. I really don't know that much about electronics, but sometimes I buy old tube radios, recap them, and see if they work. I don't really know how to troubleshoot anything. I've had no formal training in electronics, but I try. The only thing that is on the circuit board is the number 92-551. It has a ferrite bar type antenna. The transistors have metal cases and the one transistor that I CAN see is a Mitsushita SB 172. What looks like it could be the output transformer has blue tape around the core. If I can figure out how to get my pictures resized and able to post them, I'll try to. Lew
     
  7. absf

    Senior Member

    Dec 29, 2010
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    372
    2SB172 is a PNP Germanium transistor for audio amplification stage. Should be Matsushita or National.

    Allen
     
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