Would it be beneficial to TX relay shunt a FT primary VD resistor on key to compensate for TX volt drop to the amp, and still maintain a 5.0v RX filament feed for extended tube life ? vk4tux He notes
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Sun, 5 Jun 2022 15:39:11 +0300
The line voltage was 235, about what it usually is. The amp is wired for 240v (my model also has a 220v tap). When I removed the resistor that I had added, the filament voltage was 5.1 volts in stand
Author: gudguyham--- via Amps <amps@contesting.com>
Date: Sun, 5 Jun 2022 12:47:51 +0000 (UTC)
Leave it without the resistor. Dont mess with it anymore. Tube failures are more likely G-F shorts. Sent from the all new AOL app for iOS The line voltage was 235, about what it usually is. The
Vic, This may be unrelated to your amp issue, but I nearly ruined a FU728F tetrode tube because of filament voltage starvation. That tube uses a 9.0 VAC filament. The amp is an OM Power 2000A+. The
One also needs to make sure they are measuring the filament voltage with a true RMS voltmeter. Most cheap meters wont do that. Did you take a look at W8JI's site for measuring filament voltage. He do
Thanks, Paul. I'm going to look into possible line voltage drops. I can think of some areas of concern that I can improve. Thanks for the signal report! I'm running about 1300-1400w into a dipole at
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Sun, 5 Jun 2022 17:56:16 +0300
I read his article. He uses an RF filter. I might try that. My meter is a "good" one, a Fluke. But of course I've never sent it out for calibration. 73, Victor, 4X6GP Rehovot, Israel CWops #5 Formerl
Tack a 10k resistor to each filament pin, 10nF decoupling between the loose ends then twisted pair out to your DVM. Should filter out the rf and you don't have to worry about shorting the wires toget
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Sun, 5 Jun 2022 19:19:25 +0300
Good idea. 73, Victor, 4X6GP Rehovot, Israel CWops #5 Formerly K2VCO https://www.qsl.net/k2vco/ On 05/06/2022 18:41, Steve wrote: Tack a 10k resistor to each filament pin, 10nF decoupling between the
Why make rocket science out of this? *You MUST use a true RMS reading meter, or don't bother to measure it. .2 or .3 volts is a big deal which the non RMS meter will at least will be off by.* 73, Jim
On my YC156 amp, I have a pair of chokes, going from the heater connections to banana sockets, with bypass caps, on the rear panel. Makes it simple to measure the voltage at any time. 73, Alek, VK6AP
<This morning, for some reason, the phenomenon did not occur. I was <getting close to 1400 watts the whole time. I always operate CW in the <SSB position -- the warning in the manual against this is
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Mon, 6 Jun 2022 21:09:04 +0300
Not very hot. I have a bias control circuit that cuts the tubes off completely when the key is up. <snip> the TL-922 will run quite a bit slower, with much less RPM..and cooling. When I got the TL92