The commission has (finally) released the "Omnibus" Amateur Rules Changes ... included is a lifting of the "10 meter ban." See: FCC-06-149A1 1 73, ... Joe, W4TV ______________________________________
can occur between 26-28 MHz. The new rule sounds great at first, but outside of relatively complex circuitry, how does a manufacturer offer a traditional (no microprocessor or internal freq. counter
Paul, Years ago the Alpha 77Dx was manufactured with one 8877 tube and a square plate that could be removed to add a second 8877, making a 77Sx. People over America offered the "second tube kit" comp
If your amplifier has a microprocessor, it shouldn't be too tough to sense the input frequency and cause the amp to shut down within the specified limits. And since it would be in firmware, it would
Why would an amplifier need a microprocessor unless it had auto-tuning. And just by switching to manual tuning you get around the problem. _______________________________________________ Amps mailing
Bill, Correct. Those Italian RM amps use what they call an inhibit circuit. They either have a high pass or notch filter, I forget which, set at 11 Meters. The filter is connected to a RF triggered r
"Years ago the Alpha 77Dx was manufactured with one 8877 tube and a square plate that could be removed to add a second 8877, making a 77Sx...." Yes, I own one with the plate still intact. Back in the
I spent several years of my life as one of the "authorized" handful doing 77SX conversions. We had quite the assembly line running at one time. My first SX arrived in three boxes. The big crate, the
Ok, would they be able to supply the anode current for the additional tube? What would be the point in a second tube in an amplifier that would already surpass legal limit? Thanks, Doug - N9XTF Quoti
Jim Exactly right. When I was manufacturing the ARD 230 (microprocessor controlled, auto tune) series of amplifiers we did just that - we simply "locked out" those 11-meter frequencies in software. h
Harold, My apologies, I was under the impression that a single 8877 with the appropriate power supply would produce 1.5KW easily and over 2KW PEP. I assumed that 2 X 8877 would be way over that, agai
HAHAHA, Any of you guys actually run amplifiers? You guys plug them into 120 or what? Yeah I'm feisty today. A correctly ran 8877 will exactly put out 2500 watts... It will put exactly 1500 watts int
Oh sure, an 8877 with 4KV on the plate will do the full boat, but a factory edition 77Dx will not achieve 4KV even with the key up, much less down. Even abusing the box in SSB and running CW won't ge
Ray Heaton, the Alpha tech specialist at one time was vehemently opposed to the after-market program. I suppose he knew about the inability of the small doorknobs to support the circulating I've hear
Hello Paul and all others, You all bring up several questions to mind, or rather comments. 1. If an Alpha w/ an 8877 will produce 2500 watts PEP, why would one need a second 8877 in the same amplifie
What is the advantage of the second tube? Would the original power supply handle the additional current requirements to drive the second tube to full potential? Thanks, Doug - N9XTF Quoting Paul Chri
Not that anyone on the list would really care, but running two tubes at legal limit should reduce the IMD products (Splatter) if they were biased correctly. Lower efficiency but cleaner signal. Natur
Bill, Yes, I do care. That was why I was trying to understand why 2 tubes would be used. The only obvious senerio that I could come up with was that someone would be trying to run 4 or 5KW, not the s
Your scenario is really the only one anyone would use Doug. The real reason is to run more than the 2.5kW output the single tube amp would do. A single 8877 run full tilt is cleaner than any amateur
You could actually run much higher peak envelope output power under the old rules than you can today. With the new rules we lost ground on the power we are allowed to run. Few realized what really h