The Knight-Kit Radio Broadcaster Amplifier - My Story - by Jim Addie

This is a work in progress...you are welcome to view my rough draft below.

In 1962 I coaxed my father to buy a microphone.  I had watch newscasters and game show hosts on TV, and was fascinated at the age of 8 at the concept of an acoustic transducer.  I had been behind the "hifi" and noticed a jack marked "XTAL MIC".  There was a position on the selector switch on the front, just past the PHONO position for MIC.  When I asked my father what this was for, and he said it was for plugging in a microphone, it became an obsession.

One Saturday, we took a trip down to the Allied Radio store on Western Ave. in Chicago.  I had never seen such a place; a huge Sears-Roebuck sized  "superstore" crammed with electronic goodies for as far as my young eyes could see!  After letting me browse for a while, we placed our order for a microphone, which turned out to be the cheapest we could find in the catalog.  Soon, a box with the small white plastic cased mic was ready at Will Call.  We picked it up, and along with an RCA Phono plug, we made our purchase and headed home.  I recall sleeping all the way home.  Allied exhausted me!

That evening, we warmed up the soldering iron, a huge 100 watt IRON, and my dad soldered on the RCA plug.  We plugged it into the mic jack of the HiFi, and I dragged the cord through the kitchen door.  I set up a TV traytable in the kitchen, grabbed the newspaper (the Daily News), and attempted to read then news!  Too bad I couldn't really read all that well, but it was a start.

The HiFi also had a switch around the back for an extension speaker.  Soon, I was bugging Dad for a small speaker to connect to it.  Some friends across the street told me that they had just built a speaker.  They meant the built the cabinet, but I told my dad they had built the speaker.  He (and I) took it literally!  It took two nights of sawing up plywood and pine, winding magnet wire around a cone made from a manilla folder, and making a magnet assembly from a huge ceramic bar magnet, but my dad turned out a speaker - built from scratch!  I wired it to the HiFi and it worked!

Our speaker, nifty as it was, was not very efficient. Its 6" cone on a 10" frame just didn't move enough air.  I'm sure it was a very low impedence too, like around a half an ohm.   Soon I wanted something smaller and louder.  We visited an "antique shop" that had seemingly hundreds of speakers hanging from the rafters.  I zeroed in on a 6" pincussion model, and we took it home for 69 cents.  I was almost too excited to wait to put it in a box, but Dad insisted we make a box for it.  A small, square plywood box was built, and the speaker was mounted.  I didn't wait to put grille cloth on it to try it.  We wired it to the HiFi, and it worked!  I never did get around to the grille cloth, and it wasn't more than a few weeks before the cone got kicked in.  The speaker still worked, but the cone was badly ripped.

One late fall afternoon, my folks were out in the yard raking leaves.  I went into the basement workshop and found two coils of bell wire.  I also found a roll of black electrical "friction" tape.  Taking these upstairs, in no time I had wired my little speaker to the HiFi using bell wire and tape.  I put the speaker in the living room, and stretched the wires into the dining room where the HiFi was.  To avoid tripping over the wires, which were springy and difficult to control, I taped them to the white baseboard with black friction tape.  I then began "broadcasting" to the living room!  I was so proud of my little system, that I called my parents in from the yard to see it.  To their credit, the didn't freak out at the black tape on the nice white baseboard.  They first listened to what I had done, then explained that the tape and wires couldn't stay.  I saw their point, and removed them reluctantly.

That Christmas, I was given the Knight-Kit Broadcaster.  When I opened the box, my father explained that now I could broadcast to the living room without taping wires to the baseboard!  We built the kit together.  I learned to solder, learned to be patient while constructing a kit, and when it was finished, we proudly placed the Custom Built By label on the bottom: "Custom Built By Jim and Daddy".  We plugged it in, and when we turned it on, the 12AX7 lit up like a lightbulb as current surged through the cold 50C5 filaments.  It soon stabilized into a warm glow, and we searched the dial for our signal.  We found it, made some tuning adjustments, and we were on the air!

In the next few years, my little broadcaster was used to transmit to radios, and as a small PA system with my speaker connected to it.  I found that if you turn up the volume to the max, it broke into oscillation, which was great for "jamming" my neighbors radio.  Of course, my reputation in the neighborhood as an electronics kid blew my cover quickly.

During my high school years I used a mic mixer, a tape recorder, a turntable and a reverb amplifier to transmit real radio shows around the block.  I'd put on a record, grab my transistor radio and head out to see how far it would go.  I connected an "illegal" long wire antenna on my roof top to it, and it covered a couple of blocks with a receivable signal.