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Transistor Radio Amp hack- Need help....I'm back

Man it has been a while. I have taken a loooong time off away from the forum and building anything.

So, I am recently wanting to get back into it. And also a bit rusty.

I am wanting to build some little portable amps from older transistor radios.

I picked one up today from the local flea market for $7.50

It is a general electric All Transistor radio, I think dated around the 60's.

I found one on ebay for around 20. So I think I made out. Here is a link to that ebay post, just so you can see what I am dealing with.

http://www.ebay.com/itm/Vintage-General-Electric-GE-All-Transistor-...

Anyhow, my question is. One, I opened it up and at first look it looks like it took a 9 volt, but when I went to try a 9 volt, the battery terminals in the radio are too far apart to fit a 9 volt just so slightly,. I did touch the terminals and I can get some static, and that is good, but I can't hook a battery to it. So am wondering if I could cut the battery cable and install a 9 volt battery cable, or maybe try another battery like a C or D and install a battery connector inside. There seems to be plenty of room for at least a C battery

. Also, when I get this thing up and running, where should I splice in my wires for my 1/4 jack?

And since I did try it and I had just static and no radio? What does that mean? since there is no AM/FM signal for it to puck up would it work? Not really knowing how a transistor radio would work. Since I have static, surely I can get my set up to work. Obviously I don't want the radio to work, which would be a good thing. I was hoping to find any spec sheets on line, But I'm coming up on empty. Any help wold be great, my goal is too have a small amp, big tone, and portable.

I also bought one of those paper jams toy speakers today for $2.50, it turns on. I was wanting to take the guts out of it and maybe turn it into a little amp as well, any help would be great too. Thanks

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Permalink Reply by JL on April 21, 2017 at 1:56am

1) there is a group on here for just that

http://www.cigarboxnation.com/group/vintage-radios-converted-into-g...

2) found this with a quick google search about old radio 9v doesn't fit

https://forum.allaboutcircuits.com/threads/help-troubleshooting-old...

and it may be a 6v or 22v or something else. dig in carefully and you should eventually be able to determine what its power requirements are before you splice in an alternate battery connector.

3) use some alligator clip jumper wires to explore and find a good tie-in point. at the band selector switch or at the volume knob input are 2 good candidates.

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Permalink Reply by Timothy Hunter on April 21, 2017 at 2:14am

without a circuit for the radio it would be hard to figure out where the audio comes out of the RF section and goes to the audio amp section. my best guess would be to trace back from the speaker connectors. the amp section shouldnt be too complex but if you dont have any electronics experience it might be difficult. high res clear pictures might help but i cant guarantee anything...

Are there any marks on the battery case or inside it giving battery voltage or type?

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Permalink Reply by JL on April 24, 2017 at 3:51am

that's one reason to try to tap in at the AM/FM(TAPE) selector switch when hacking an amp out of a radio/boombox/ its a common point where all signal out circuits meet to go to the power amp.

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Permalink Reply by Timothy Hunter on April 24, 2017 at 3:54am

good point but i think this is just a transistor radio. so no selector switch to hack. yep ebay link shows an old AM radio...

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Permalink Reply by Timothy Hunter on April 21, 2017 at 2:32am

http://www.diystompboxes.com/smfforum/index.php?topic=97012.0

found an article on the PJ amp . uses a small transducer to vibrate the cardboard front. would easily transfer to a Cigar box. but it looks like it need a 10 x preamp . has line level input so a small boost pedal between the git and amp would do the trick.

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Permalink Reply by Timothy Hunter on April 24, 2017 at 3:59am

found another ebay listing for a similar radio. this one has a pictures of the inside. does say 9v everready 266 battery

http://www.ebay.com/itm/Vintage-General-Electric-GE-All-Transistor-...

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Permalink Reply by Jerryrig240 on April 26, 2017 at 12:34pm

well I found a video on line of someone who rebuilds these types of radios. Just by watching the video, it answered my question and that I can run the radio off of 9 volts. He has 4 batteries wired into the radio, that equals 9 volts, so I am hoping I will be okay with a 9 volt battery. I have not tried to tinker with the radio much, but I hope in the next few days to tear into it and check out to see if I can get it up and running. Here is a link to the video and him talking about it. He has a ton of vids on youtube of rebuilt radios, so if you have a question about a radio, I am willing to be he has it on his channel. He has a ton of them.

https://www.youtube.com/watch?v=jhpR8C8jqG0&feature=youtu.be

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Permalink Reply by Timothy Hunter on April 27, 2017 at 10:10pm

you might be able ti inject you guitar signal at the volume pot. usually one end is ground the signal comes in at the other end and the signal from the wiper goes to the radios amp then speaker.