Discussion in 'Amplitude Modulation' started by AL7RU, Jul 11, 2016.
That cheap iron could be put to use elsewhere.
You know, just to shed a little light on the process here. The transmitter is only the start of it. They are not hard to move up to 160 or 80 meters though. The Gates I moved I crystal controlled. There's only a couple places on a band where AM phone is welcome anyway and don't think about multi-banding one of these. The less adjustment available the better off you'll be. But, you need some pretty expensive speech processing equipment in front of the modulator driver too. I used a UREI LA-4 on mine that I got from a guy like Dennis for about the price of the transmitter. A decent microphone, an antenna system and transmission line capable of handling the power. It wouldn't hurt either to have your neighbors far enough away to avoid problems. It was a very satisfying endeavor in my case though and I hope to do it again one day. When you move one take the transformers and tubes out, remove any separate modulator or exciter decks out and let them ride separately. Stations used to be required to have a broadcast engineer on site 24/7. Not so any more. Most stations rely on contract guys to come in a keep things going. As a result, often these old transmitters are in pretty bad shape when they hit the street. This one is probably no exception. My Gates had the remains of MANY blown up oil filled capacitors all over the inside of the transmitter. The hazards of PCBs are over-stated in my opinion but you do have to clean all that gunk up. In the end, if you move it to 75 meters, you'll make money on your time and trouble. I did.
Dennis W7TFO should tell the story of how McMartin went out of business and the BIG event that "led the horses out of the stable" during the NAB show in Las Vegas. Very Very Funny!
AM Fone and AM North America are dinosaurs....
The best McMartin story I know was that about the time during an early 80's NAB show in Las Vegas. The NAB (aka the grand mal seizure of radio & TV) guarantees a LOT of people in attendance, upwards of 100,000 over the few days it runs.
On radio row, the big transmitter guys Harris & Continental were across the aisle from each other. McMartin was right at the same intersection, with one of their new 50kW AM rigs powered up and running into a water-cooled dummy load. They had some measurement gear, a scope and mod monitor, hooked up and were feeding it music or sine wave tones.
I was down the aisle looking at a new spectrum analyzer from Tektronix when a really funny trace appeared on the screen. Just then, there was a loud bang, screams & shouts.
It seems that they were showing off how the big 50 could eat up some 15kHz audio tone @ 100% mod, and it let go with gusto.
I followed the crowd down that direction; there is was, flames and smoke out the top. Radio bedlam @ McMartin...
The guys from Harris and Continental were just shaking heads and snickering.
The best thing was a placard on an easel showing this very transmitter was sold to some radio station. The guy from that station wasn't plussed by the failure, and he tore that sign in two and tossed it on the floor....I'd guess the deal was off.
Holy Crap talk about embarrassing.