The Studio - Part 2 aka The Transmitter

In 1967 I constructed a make-believe studio in my bedroom.  Over the next year, or so, I actually took that to the next level with some help from Radio Shack.

I discovered Science Fair P-Box kits and started buying them on a fairly regular basis.  Building them was fun and they usually worked as advertised.  I can remember building the AM radio kit, the FM radio kit, the metronome kit and the goofy neon light kit among others.  Here's a link to some info about those old kits: Click here.

I also built the AM wireless microphone and the FM wireless microphone.  As I recall I never got the AM version to work, but the FM version worked perfectly.  Here's the manual for the FM Wireless Microphone:
28-109


If you read between the lines, you can see that this is actually a small FM transmitter.  And here's where I took my bedroom studio to the next level.  By 1968 I had a stereo record player that had an output on it, a tape recorder and a microphone.  I actually fed audio from the record player, as well as the mic amplified by the tape recorder into that little FM transmitter and started "broadcasting" from time to time.

I could receive the signal up to 5 city blocks away from my house - pretty amazing for that kit.  My record library was very limited, but an album side would play for more than 15 minutes on its own.  During that time period, there were companies that sent audio presentations on a flimsy tear-out record in the mail - so I even had commercials.  One I remember is Cherokee Village Resort in Arkansas.  These tear-out records also appeared in magazines and books.

A little radio history was made in Mexico, Missouri

I was at Forest Park Community College in St. Louis in 1975, while a bit of radio history took place in Mexico, Missouri.  The first solid state AM transmitter manufactured by the Harris Corporation was put in service at KXEO.  Hilmer Swanson headed up the design and manufacture of the Harris MW-1 in Quincy.  From a Harris Corporation newsletter:
Harris Corp March 1975 Newsletter MW-1

That MW-1 was still in use when I started at KXEO in 1978.  In 1980 the station purchased a larger FM transmitter from McMartin, and at the same time purchased a new BA-1K AM transmitter.  I was told the Harris MW-1 was "traded in" to McMartin,  as McMartin was very interested in the solid state technology.  While the BA-1K had a solid state exciter (the first modulated power stage of a transmitter), the BA-1K relied on 4 tubes to achieve its 1000 watts.

You may be wondering why the station would have gone from the newer all solid state technology of the Harris MW-1 back to tubes with the McMartin BA-1K. The KXEO tower at that time had massive amounts of static electricity jumping around the tower and guy wires with each passing thunderstorm, and that was enough of a jolt to the MW-1 to take out the final power stage on a fairly regular basis.