Thursday, October 15, 2009

Home brew again

In a previous post, More Home Brew: The Knight Kit, Ron Henselmen described his adventures with his friend Gary Wegner at kit building and amateur broadcasting.  Here's a follow-up to Ron's story:

PART II: Bud and Ron digress:

Cool story! I also played with Part 15 transmitters, but they were transistorized and, much later in life. I used to DX pirates, so I got a bunch of tapes from them. I have a Ramsey FM-10 that I used at Hamfests as a display (us Hams can use them for other things than broadcasting!), but I put some of the funnier pirates on, just for shock value. Yes, I i.d.'ed as a Part 15 broadcaster, following the FCC guidelines, but STILL got a Ham or two wanting to file on me!

Later, a pirate sent me a Ramsey AM-10 (?), modified with plug-in capacitors to quickly change operating ranges. I've never tried it, never hooked it up.

I have a Ramsey FM 100, and I built an amp with a low pass filter for it. I never designed a VHF RF amp using an RF power transistor before, so it was a good learning experience for me. That was in 2000. I ran the FM-100 without the amp as an automated oldies station using WaveStation software, but the novelty wore off quickly.

There weren't many pirate stations when I was an active DX'er, so the only thing I ever heard was a pirate on 101.5 MHz. That was about twenty years ago. There aren't any local stations occupying that frequency, so I use it to check VHF propagation. That is also the frequency I used for the Ramsey transmitter.

I never bothered to read the part 15 rules until I bought that transmitter. It never dawned on me that the rules between the FM and AM broadcast bands might be different. I thought one could use 100 milliwatts with a 60 inch antenna on FM too. My fun came to a close when I saw people getting busted for running things which were only slightly questionable; I didn't want to lose my commercial license or my amateur license.

It will be fifty years in December or January since I built my first transmitter from just parts. I built it into a cigar box, and I used the 90 volt battery out of a tube type AM portable radio to supply the voltage for the tubes. Gary Wegner reminded me about how I got into trouble in seventh grade for bringing it to school. I left my transistor radio turned on, but the transmitter was turned off with a toggle switch. A classmate decided to be cute and flip the transmitter power switch on during the middle of class. The transmitter was setup to transmit tone modulated Morse code, so the tone blared out of the transistor radio while my teacher was talking. She was not impressed, but I didn't get into any major trouble. Later, I made the unit into a voice transmitter. I hated Morse code at the time.

Sometimes we were asked to bring portable radios to school, so the whole class could listen to some history making event.   Everybody else in the class would have their radios tuned to the Chicago NBC station, and we would have ours tuned to the Milwaukee NBC station.  We would play dumb when the teacher asked us why there was a delay in the audio between our radios and the rest of the radios in the classroom.  The attached photo will show what I looked like about the time of the multiple radio incidents:

Dave mentioned seeing catalogs that his father received from Allied Radio. Their main store was on Western Avenue in Chicago. I loved going there; it was a sad day when most of the company was purchased by Radio Shack. They had what they called a dock sale shortly before closing down the store. I went there along with Gary Wegner. We bought speakers, turntables and headphones. I finally had money to buy things because I saved most of what I earned in Vietnam....

Have you ever heard some ridiculous claims from pirate broadcasters or illegal CB'ers as to how much power they are running? Some of them can't do the basic math to figure out their electrical circuits can't handle the amount of current required for their claims. 240 volts X 100 amps = 24000 watts total available to the typical older home with 100 amp service. I have a fifty amp 240 volt electric range outlet just to run my VHF amplifier. I never argue when I hear those claims; I just chuckle.

 Thanks, Ron and Bud, for the memories!
---Dave S.

No comments:

Post a Comment