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Comment by Corbie on July 28, 2017 at 3:39pm

Yeah Micheal I get e-mail every time someone makes a comment. So here is the deal. I'm older now but not any wiser. I posted those pictures 5 years ago and I had a lot of those radios I picked up back then off job sites or the trash. I never refuse a portable radio. I couldn't find the info I used back then so bear with me while I try to activate the brain cells. First to clear up the power source question. The on board plug into wall power is what it is. Actively at some moment there is 120 ac volts sitting in there just waiting to zap you so don't be messing with those wires. It is most always conveniently near the wire with the wall plug in it. From there it goes through a transformer and some diodes and electronics that turn it into the nearly same DC volts the batteries stack up to be. Notice that there are wires going through switches and to the batteries. This is to separate the 120 ac from the batteries. If it doesn't have that selection switch then it is built into where  you plug in the cord....pull out the power cord and it goes to the batteries. Remember your batteries have positive and negative(ground most of the time) so keep this in mind when it comes time to wire in the jacks. If the radio has the wall wart power source you can forget all that I said just now except the part about the +&- part. All my radio amps can use both power sources without a problem. I'm not sure why anyone would think you could use only one source. Next point.......I like to use the tape player  to use as an input. One picture shows the tape head wires. Using this method you have to disconnect the power to the motor by clipping it's power wires or some have plugs to unplug. To use you put the radios selector switch on tape machine and as I remember there is a switch that recognizes that there is a cassette in. Those wires need to be connected together . I never tried hooking the CD part so your on your own with that. On the 8track player I used I have to slide in an old 8track tape in to activate the amp. Next point....... I had figured out at one time how I used the radio part but would have to really open up a radio again and refresh my memory. I do remember I always used the AM side of the radio because you are adding an input and need to silence the radio signal. There should be a internal antennae that has very special  thin wires to cut so it won't pick up a signal. I always would keep the FM intact.  Next point......an input is an input. Remember your positive and negative so all things correct you possibly could add other sources but may or may not need a preamp.  Next point.....if you consider to sneek in sound effects it has to go in where the input jack is and would have to power it on its own or if you know what your doing hook in the radios power into it. I wouldn't bother I would hook it up externally. As far as adding that Psychknob you might not find enough room to get it in there and may cause interference and may need to be shielded . Sounds like something I would personally try. Maybe the last point and most important.  What is that radio worth other than paying only  a mere $7 for it. I collect old radios and found some really great radios for little money. I would suggest that you to get a trashed radio and experiment with that one first like I did. I have 2 plastic totes full of smashed radios, all have been stripped down and tested and  to be put in their own little boxes at another time. If I have left anything out here it's because I have forgotten stuff and would to get back into the radios internals again to remember.  I just don't see that happening too soon...... Ask more questions if you like but I may not have any answers at this point. Hope this ongoing boring tech talk  helps. Good luck and if you get yours done post it here so I can see your hack.

Comment by Michael F. Copado on July 28, 2017 at 11:59am

I don't know if you check comments to thipost, but I have a couple questions. I found a great 1970 Sears Roebuck radio today for 7 bucks and I want to use it for a cigar box guitar amp. If you have a radio that takes batteries AND can be plugged in, is it safe to use with AC, or do I have to use it only with batteries? I can't get a clear answer, most of the people who post these things say no, but they also say they no nothing about electricity and radios, so I don't know how accurate it is. Also If I have a dual band Am/FM radio, can I wire the jack into the two way pot instead of the volume knob, that way let's say I could keep the am band and swtich the pot to the fm side for the guitar (actually what I'm considering doing is putting in a mini computer audio jack so I can use it as speaker for my computer or headphone jack on my phone.) I'm also considering swapping out the tuning knob with an Artec Psychknob effects board/pot. I'm wondering if that would work and if I'd run into trouble with powering it, especially if the amp could work plugged in. Any thoughts?