Part 97.307(A): No amateur station transmission shall occupy more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice. Wit
Part 97.307(A): No amateur station transmission shall occupy more bandwidth than necessary for the information rate and emission type being transmitted, in accordance with good amateur practice. Wit
In Part 96.113 Broadcasting and Music are specifically prohibited. The only justification for medium fidelity of high fidelity audio is for "broadcast" purposes ... in fact, licensees in the medium a
You may be able to prove that humans can distinguish certain letters, words and sounds with 4K audio that they can't with 2.5 K. That's not the issue. The issue is that Bell Labs and other competent
In this area we agree ... I have no problem with 300 to 3000 (2.7 KHz) or even 300 to 3300 (3 KHz) it is those who push it to 100 Hz to 4 KHz or even 20 Hz to 5 or 6 KHz that I find objectionable. Wh
Mike, Contact Dick Frey, K4XU. Dick is Manager of RF Products at APT. I believe the ARF1505 is the subject of an article in QEX (July?), is being used in a Tokyo High Power Labs amplifier and "may" b
Mike, Contact Dick Frey, K4XU. Dick is Manager of RF Products at APT. I believe the ARF1505 is the subject of an article in QEX (July?), is being used in a Tokyo High Power Labs amplifier and "may" b
I received a note from K4XU the other evening ... The Tokyo High Power article was missing from the July QEX - no reason why it did not appear. Both THP and Dick were surprised as they had been told
For those interested ... Richardson's (www.rell.com) small volume price (on the ARF1500, etc.) is about $235 - with a minimum purchase of four. There are currently no application notes available from
Why would you bother with sweep tubes? With the 811A at $16 (RF Parts) you're in the same price range for a more rugged tube. Four 572B tubes will provide nearly 1500 W PEP in the same price range ($
The Drake TR-4CW used three 6JB6 sweep tubes with 650 volts on the plates ... rated for 300 W PEP input. If I recall correctly, it would do a bit better than that ... the T4XC transmitter had a pair
Be careful of Steatite ... several kinds will absorb moisture and cause problems. I had to replace the feedline at a television station (1600'+ of 3 1/8" rigid line) a few years ago because the Steat
If fusing the grid is so "safe" why is it not used in commercial transmitters? If it protects a tube so well, why has no tube manufacturer recommended it (they recommend a surge limiting resistor in
Non-sequitur, grid fusing was not installed even in the newest tube transmitters. In fact, the grids were generally bolted directly to the chassis wherever possible. If they can't be bolted to the c
There you do again ... there is no need to directly interrupt the grid current with a transistor. As long as the anode has sufficient current limiting (arc protection) which is normally provided by t
Will, Here's the problem, If the tube has an internal arc or is drawing heavy current between grid and anode the grid is already essentially at the anode potential, opening the grid to ground circuit
You have obviously not been knocked on your but by a capacitor that is totally disconnected from the circuit and in storage. There is a reason that high capacity devices are shipped and stored with a
How does current flow vertically in a helical filament? The current must flow in/along the conductor - that's substantially horizontal which if I remember my physics from 40 years ago makes the force
Not likely ... Alpha did not use grid trips in any of the '76 or '78 series amplifiers. I believe they converted to the 3CX800 in the 86 and 89 amplifiers. I know that all of the 8874 amplifiers tied
You're the one who raised the capacitor issue: The grid can and will become positive in the presence of an electrode stream and voltages on the other electrodes. A screen will certainly go to full an