kl7aj
05-04-2007, 03:13 PM
Well, the boat anchor problems seem to be popular; we have quite a few folks versed in heavy iron technology, it seems. Here's one for the real broadcasters. (Of course, anyone's welcome to give it a shot!)
Kiff Nilgard is chief engineer of KXXX, a 50KW non-directional AM talk radio station. The late night DJ, Yack Moore, has agreed to stick around as a safety guy and general gofer. It is half-past midnight, and Kiff has just swapped out the triode final on his transmitter, a conventional high-level class C iron horse, with a rebuild from that company in Woodland Hills.
He dutifully measures the filament voltage at the socket with his Fluke DVM, and sets it to precisely 12 Volts DC. He lets the filament cook in while he drinks coffee and swaps lies with Yack. The two hours pass quickly enough. Kiff remeasures the filament voltage, it hasn't changed one iota. He buttons up the back panel of the transmitter.
With Yack looking over his shoulder, Kiff hits the Plate voltage button, and the transmitter kicks on uneventfully, no gas pops or oscillations. He looks at the output meter, and it's up at 60 kw. "Wow, that tube is a smoker!" Kiff remarks. He reduces the Plate Loading to bring the power out down to specs, also re-dipping the Plate Tuning. He walks the loading and tuning controls for the best efficiency. The transmitter is as happy as it's ever been.
"Hey, Yack....give us a bit of chatter, and I'll re-kajust the modulation. You can throw in a bit of that stuff you call music, just for good measure."
Yack runs up to the studio and fires up the mike. "You're listening to KXXX, Kix radio, on the air for equipment testing. This is radio station KXXX. You're tuned to radio station KXXX. KXXX is on the air for equipment testing. It is three oh seven A.M. You are tuned to KXXX, Kix radio, for the purpose of equipment testing. And now for some music...."
Yack rematerializes in the transmitter room. "You look like a happy man, Mr. Kiff."
"Yes. We're hitting 130% on positive peaks with no effort. It looks like we're ready to go. Give one more ID and we'll kill it. We'll leave the filaments on though. Probably a good idea to let them run all week."
"Yeah. Since we're going 24 hours next week, that might be a good idea," Yack remarks.
"Oh yeah!" Kiff says. "Say, you aren't so dumb for a DJ, after all!"
Kiff leaves Yack to close down the station, and goes home a happy man.
Until the next morning, that is. He is awakened at 7 A.M. by the morning DJ. "Hey Kiff. We're getting reports all over that the station sounds muffled or muddy. I think you'd better come in and take a look."
"Oh !@#$%^&*(" Kiff says, prying his eyes open.
What is the problem? What is one possible solution?
Eric
Kiff Nilgard is chief engineer of KXXX, a 50KW non-directional AM talk radio station. The late night DJ, Yack Moore, has agreed to stick around as a safety guy and general gofer. It is half-past midnight, and Kiff has just swapped out the triode final on his transmitter, a conventional high-level class C iron horse, with a rebuild from that company in Woodland Hills.
He dutifully measures the filament voltage at the socket with his Fluke DVM, and sets it to precisely 12 Volts DC. He lets the filament cook in while he drinks coffee and swaps lies with Yack. The two hours pass quickly enough. Kiff remeasures the filament voltage, it hasn't changed one iota. He buttons up the back panel of the transmitter.
With Yack looking over his shoulder, Kiff hits the Plate voltage button, and the transmitter kicks on uneventfully, no gas pops or oscillations. He looks at the output meter, and it's up at 60 kw. "Wow, that tube is a smoker!" Kiff remarks. He reduces the Plate Loading to bring the power out down to specs, also re-dipping the Plate Tuning. He walks the loading and tuning controls for the best efficiency. The transmitter is as happy as it's ever been.
"Hey, Yack....give us a bit of chatter, and I'll re-kajust the modulation. You can throw in a bit of that stuff you call music, just for good measure."
Yack runs up to the studio and fires up the mike. "You're listening to KXXX, Kix radio, on the air for equipment testing. This is radio station KXXX. You're tuned to radio station KXXX. KXXX is on the air for equipment testing. It is three oh seven A.M. You are tuned to KXXX, Kix radio, for the purpose of equipment testing. And now for some music...."
Yack rematerializes in the transmitter room. "You look like a happy man, Mr. Kiff."
"Yes. We're hitting 130% on positive peaks with no effort. It looks like we're ready to go. Give one more ID and we'll kill it. We'll leave the filaments on though. Probably a good idea to let them run all week."
"Yeah. Since we're going 24 hours next week, that might be a good idea," Yack remarks.
"Oh yeah!" Kiff says. "Say, you aren't so dumb for a DJ, after all!"
Kiff leaves Yack to close down the station, and goes home a happy man.
Until the next morning, that is. He is awakened at 7 A.M. by the morning DJ. "Hey Kiff. We're getting reports all over that the station sounds muffled or muddy. I think you'd better come in and take a look."
"Oh !@#$%^&*(" Kiff says, prying his eyes open.
What is the problem? What is one possible solution?
Eric