I've finally applied full drive to my 4CX1000A amplifier. Here is what I'm seeing: I have tried two tubes, both pulls. In one case I can run about 1kW out, and with the other, maybe 1200. What happen
Vic, what frequency? Does the plate current drift? Screen current is extremely sensitive to the degree of loading adjustments. Could it be that there is a capacitor on the output side of the plate tu
Gerald, I have only tested so far on 40 meters. There are no fixed capacitors in the tank on this band...but there is a ferrite choke across the output. I'll check to see if the choke is heating. I d
I've finally applied full drive to my 4CX1000A amplifier. Here is what I'm seeing: I have tried two tubes, both pulls. In one case I can run about 1kW out, and with the other, maybe 1200. What happen
Now, here is something that has really puzzled me. Plate, and grid dissipation is due to kinetic energy of the incident electrons striking the plate or grid and not the secondary electrons emitted. S
I've finally applied full drive to my 4CX1000A amplifier. Here is what I'm seeing: I have tried two tubes, both pulls. In one case I can run about 1kW out, and with the other, maybe 1200. What happen
Vic, Gerald may well have a point about loading. What inductance is the plate choke, what capacitors are there at the 'cold' end of it and what type and is there another smaller RF choke going off fr
What band? Are you using padder capacitors on the loading cap? 73 Jim W7RY On 11/7/2013 3:14 PM, Vic K2VCO wrote: I've finally applied full drive to my 4CX1000A amplifier. Here is what I'm seeing: I
Thanks to everyone for your responses. Here are the answers to all of the questions, plus latest results. The band is 40 meters. There are no padder capacitors in the circuit on this band. There was
Thanks to everyone for your responses. Here are the answers to all of the questions, plus latest results. The band is 40 meters. There are no padder capacitors in the circuit on this band. There was
Nothing wrong with a triode, but you can have more control with a tetrode. Working with a 4cx12,000 last night, I noticed that with zero screen voltage the transmitter was able to make around 10% rat
Tuning is VERY touchy. You really have to have the loading right or the screen current is excessive in either direction. Are the tune and load capacitors too large? Are there vernier dials on the cap
Tuning is VERY touchy. You really have to have the loading right or the screen current is excessive in either direction. None of my 4CX1000A or 4CX1500B amps were all that touchy, from 1.8 to 144 MHz
I have a vernier on it. Maybe I exaggerated -- it's not all that bad, just different. It is smooth. I just need to get used to it. A plus: the screen meter is very useful as a tuning indicator! None
Nothing wrong with a triode, but you can have more control with a tetrode. Working with a 4cx12,000 last night, I noticed that with zero screen voltage the transmitter was able to make around 10% rat
What is the loaded Q of your Pi circuit? Is that sharp tuning with the load capacitor on all bands? When tuning the anode capacitor, peak screen current with it and use load for the correct screen cu
So what is the Load cap? Carl KM1H -- Original Message -- From: "Vic K2VCO" <k2vco.vic@gmail.com> To: "N1BUG" <paul@n1bug.com> Cc: <amps@contesting.com> Sent: Friday, November 08, 2013 4:09 PM Subjec
ORIGINAL MESSAGE: (may be snipped) REPLY: This is one of the advantages of vacuum variables. As you approach the minimum, the change rate per turn gets less. Just what you want. 73, Bill W6WRT ______
Vic, OK, on 40 you have 375mA or so of RF current in the choke. My suspicion was that maybe the capacitors didn't like it or were small enough that they were heating up with RF, but it doesn't appear
Q should be about 12. I have discovered that the screen meter is the tuning indicator. I have my trip point set at 35 mA, so I have so far kept it at 25-30 mA. I have still only tried it on 40M. I'm