Discussion in 'Amplitude Modulation' started by K8CCA, Apr 27, 2021.
Yep, Ray's audio section was a bit lacking. A lot like the Bauer 5kW, too.
It can be done Pretty easily for a single band, a lot of people have done it. But the hard part is moving the heavy transmitter.
Some of them are also operated with 3 phase power
The upside is that there will be LOTS of room in there to do twiddling and tweaking.
Eric P. Nichols, KL7AJ
“Well, look what the cat dragged in!” I said, running my hand over the ancient black crinkle-finished, six-foot rack cabinet.
Joel “El Joe” Ballek, WL7AI, thrust a crusty coffee mug into my hand. “It followed me home,” he explained.
“Uh huh,” I said, glancing around the shack, cluttered from floor to ceiling with boat anchors in various states of repair. “You do seem to attract them, don’t you?” I took a sip of the boiling coffee, which closely resembled soldering flux. I inspected the empty rack, which had an unfamiliar manufacturer’s label affixed to the topmost strut. “Chrono-Tron?” I asked, skeptically.
“Yeah,” said Joel, with a shrug. “I guess it came from some atomic clock or something, once upon a time.”
“You don’t suppose it’s radioactive or anything, do ya?”
“I guess we can find out,” Joel said, in a matter-of-fact tone. He pulled out a drawer beneath the right end of his workbench and extracted a bright yellow Civil Defense Geiger counter. Leave it to El Joe to just happen to have a Geiger counter handy. He fired up the instrument and scanned the perimeter of the rack. “She’s clean,” he pronounced. He switched off the counter and put it back in the drawer. I felt safer already.
“So, El Joe; what are your plans for that rack?” I queried.
Joel sized up the rack. “I dunno. Do you think we should build an A.M. transmitter?”
Ahh, that dreaded word “we.” With El Joe, it was never the “Royal We.” It meant El Joe and someone else. Since El Joe’s faithful dog, Buddy, had passed away two years earlier, “we” could only have one possible interpretation: El Joe and me.
El Joe didn’t wait for my answer. He crouched down on his haunches, placed his hands on the side rails of the rack and slowly rose to his full height, his head tilted at a curious angle. I knew exactly what he was doing; he was drawing the schematic diagram for the infernal thing in his cranium. I’d been here before. That faraway look in his eye could mean only one thing: WORK!
Back in the Dark Ages, the rack was well-known as a torture device. Not much had changed in the past few hundred years except for, perhaps, the form factor. I couldn’t remember how many cumulative hours I’d spent lying on my back on the floor of one of El Joe’s equipment racks, bench-pressing a boat anchor or some other massive device into place while he fastened the thing into the rails. I must have been a masochist of the first degree.
Fortunately, the commencement of the work would be several weeks, perhaps several months down the road. It would take a while for El Joe to gather the ingredients for a plate modulated “heavy iron” transmitter. After all, those things just didn’t grow on trees these days.
Or so I thought.
As fate would have it, El Joe “just happened” to have a half a dozen beefy modulation transformers lying around, just behind the shack, with one of those ubiquitous Alaskan blue tarps lovingly draped over them. El Joe “suggested” that “we” bring them into the shack to thaw out. In this particular instance, Joel was using the “Reverse Royal We,” as in, “Are we ready for our horseradish enema this morning?”
Not surprisingly, the little beasties weighed between one and three metric tons each. Okay, I exaggerate a little. They only weighed between one and three avoirdupois tons each.
I managed to scoot them, one by one, around the shack and in the door without as much as a hernia. El Joe gratefully rewarded my efforts by refilling my mug with some now body-temperature rosin-like coffee.
“You knew I was coming over today, didn’t you?” I said, accusingly.
“You’re here every day,” El Joe retorted. “Besides, I need someone who knows what they’re doing.”
“Right,” I said. “Can’t I be incompetent for a change?”
“There’s time for that later,” El Joe said. He scratched his head for a moment, gazing up at the ceiling. He strode across the floor and retrieved a six-foot length of half-inch copper pipe that was leaning in the corner of the shack, by the gardening tools. He opened up another drawer and extracted a pair of huge porcelain bowl insulators.
“Open wire feedline?” I queried, almost incredulously.
El Joe snapped his fingers. “See! That’s why I have you around. Nobody else would have had a clue. We think alike.”
“That’s a real scary thought there, El Joe.” I said, gagging down a throatful of “coffee.” I surveyed the interior of the shack, estimating that the combined age of all the equipment was well over a millennium. “Ya know, El Joe. One day you’ll end up trading this all in for an XYL. It happened to me, you know.”
“Nah,” said El Joe. “I might get a new dog some day, though.”
There’s an old saying about us Alaskan men that women started circulating around the time of the Gold Rush a century ago. “The odds are good, but the goods are odd.” Obviously, not much has changed in the past hundred years.
El Joe really is a decent fellow, though. He’s got a real job. He treats his mother with respect. He’s kind to animals. You always know where he can be found. Some day, some fine lady will discover this nugget of a feller, and take him off my hands.
The sooner the better. My back is killing me.
Thanks for the info guys. I think I will keep an eye out for a local deal on a broadcast transmitter. Maybe someday I will obtain a nice unit. I need to get my Valiant and 32V-3 on the air at this point before I take on anymore projects.
Unfortunately, the heyday of finding cheap or free retired tube type transmitters at BC stations is long over. Most of the 250-1000w stations (that haven't gone dark) replaced their old xmtr with a new solid state one, years ago. There are still a few remaining, mostly serving as auxiliary (stand-by) transmitters. The rest, the ones that didn't luckily fall into the hands of hams, went to the scrap yard years ago. I missed a free-of-charge BC1-F only because I didn't find out about it in time, before it was scrapped.
But now, as the ham and AM communities are gradually "ageing out" with few newcomers following to replace them, the same thing is happening to the converted and unconverted transmitters that hams have accumulated. Often when an old-timer moves to the care-home or goes SK, those left behind don't have a clue what most of the radio stiff is, and it likely goes to the landfill.
Good point Don, maybe I will find a already converted unit. I am 56 years old, so have a few years left to play with this stuff.
As my grandfather used to say, "Ahh, you're still a youngan.' "
A Valiant runs plenty of power for the amateur bands.
I notice when I occasionally check into the "Collins AM Net" west coast edition on 75m, or more frequently just listen to it, the "big signals" are all coming from "big antennas," irrespective of power.
The big signal guys can run 20W carrier power and they're still strong.
The cool thing is they all keep working on their modulation, like forever, which I guess is the never-ending quest to sound perfect. Not such a bad goal.