I don't know if there is anything to be gained by running with reduced plate/screen voltage. These tubes are not gettered by heating the plates like 3-500Zs, so I don't know what the advantage would
I have. I installed them in 3.5mm thick aluminum angle stock when building an enclosure. There is a tool to insert them which works better than just hitting them with a hammer! It's also important (o
I faced this problem when building a 4CX1000A amplifier. The GM3SEK calculator gives you a value, but the stray plate-to-ground capacitance is an important variable and it is hard to determine. I mea
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Wed, 14 Dec 2022 10:48:31 +0200
During the early 1960s I worked at a BC station where we had a 5 kW FM transmitter. It had a full-wave bridge rectifier consisting of 4 boards, each of which had some 16 400-piv diodes on it. I think
During the early 1960s I worked at a BC station where we had a 5 kW FM transmitter. It had a full-wave bridge rectifier consisting of 4 boards, each of which had some 16 400-piv diodes on it. I think
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Wed, 28 Dec 2022 19:23:09 +0200
Older carbon resistors are often found to be too high in value. The simplest answer is to get a HV probe for your DVM and calibrate the meter in the amplifier. 73, Victor, 4X6GP Rehovot, Israel Forme
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Sat, 31 Dec 2022 07:45:12 +0200
Steve, Keep in mind that most of the step up/down transformers sold are actually autotransformers. One side of the primary is connected to one side of the secondary. This should not be a problem rega
Steve, Keep in mind that most of the step up/down transformers sold are actually autotransformers. One side of the primary is connected to one side of the secondary. This should not be a problem rega
Interesting that the 8877 datasheet gives a warmup time of 90 seconds, but doesn't say whether you can apply plate voltage. https://frank.pocnet.net/sheets/140/8/8877.pdf On the other hand, the 4CX10
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Tue, 24 Jan 2023 15:21:17 +0200
This is a test. -- 73, Victor, 4X6GP Rehovot, Israel formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ _______________________________________________ Amps mailing list Amps@contesting.com http://
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Wed, 1 Mar 2023 17:51:49 +0200
I don't see the point of paralleled contactors. The critical part is make and break, not steady state current. The danger is that contacts will be damaged or welded together by the arc that occurs on
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Wed, 24 May 2023 15:39:13 +0300
Perhaps it's breaking into oscillation? 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ I am building a HF linear amp with 2 x 4CX350A with cathode driven circu
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Wed, 24 May 2023 15:51:23 +0300
Yes, it could be at VHF or even LF. 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.
Author: Victor Rosenthal 4X6GP <k2vco.vic@gmail.com>
Date: Sun, 1 Oct 2023 23:06:19 +0300
Plate voltage regulation on a tetrode is not very important, because the screen voltage has a much greater influence on the plate current. 93 uf is quite a lot for the plate supply, imho more than yo