
First and foremost: I do not recommend anyone try what I did.
Ever.
I was very lucky that I didn't get badly shocked and die. OK?
My Dad's Uncle Matt was a Radioman in the Navy in WWII and when I was a kid, I heard about how he was a ham radio operator and talked to people on the shortwave all over the world and other interesting radio-type things and wanted to learn more about it. Today, I have earned my General Class license and have his call sign, W7IRX, in memory of him.
So, my Dad gave me this really nice Hallicrafters S-38 short wave radio. I was able to receive four bands, one of them AM radio, the others various short wave bands. I remember listening to the BBC, Deutsche Welle and even Radio Moscow propaganda back then, though my favorite was the BBC World Service.
Most of the time I listened to The Good Guys on WMCA (570kc), and Cousin Bruce on WABC (770kc) and WINS (1010kc) all from New York, and sometimes I picked up KDKA from Pittsburgh and WKBW from Buffalo. WMCA and WABC were the New York area AM rock stations in the late fifties and early sixties, before alternative programming FM came along.
When I was in 8th grade, I got my first electric guitar, a Kay. It had two pickups and it took all my strength to press the strings down to the fretboard. But I was determined, I practiced a lot and my fingers got to be very strong.
But I didn't have an amp. What good was an electric guitar without an amp? And I didn't have any way to amplify my record player (i.e. turntable).
I looked around my room and found the Hallicrafters as the only possibility. I thought, heck, the Hallicrafters amplifies the radio signal, so why not a guitar signal or a record player signal? I'm not sure those were the exact words that went through my head, but close enough.
I thought, all I have to do is figure out where the amplifying happens, then stick some wires into the radio at that point. Then connect the other end of these now loose and dangling wires to my guitar and wham-o!... I'll be all set to Rock 'n Roll!
Here's what a Hallicrafters S-38 looks like before modification. It is a very nice radio. Or was.

Well, first take that darn case off!

Looks better already, doesn't it?
Now, I figured out pretty quickly that the tubes are on the top and they are not the place to put wires to tap into the amplification section. So, I flipped the sucker over. Like so...

As you can clearly see, all the good stuff is there: switches, wires, capacitors, more wires, resistors, and still more wires, induction coils, and best of all, a speaker to make the sound come out!
Now, somewhere in there are the connections I was looking for. And I found them. I twisted wires around the places where the signal was amplified and led the wires out through the cabinet, which by the way, I had to put back on because I think either my Dad or Mom was bothered by all those loose tubes and wires and stuff. Something about starting a fire in my bedroom.
For radio fans, here's an S-38 manual in Adobe Acrobat (.pdf) format. Enjoy.
Did I mention that you should never, ever try this at home? This is dangerous stuff! There are some very high voltages inside that box and they will zap you if you are not careful.
Use this link to email Glenn and tell him what an idiot he was to fool with such dangerous electrical things.