ALL I managed to get my hands on a couple of VERY used 4CX5000 and the related parts. Although I have build a couple of tetrode (gu84b) amps grid driven, this tube has quite a different demands. In g
All I found this http://www.cpii.com/docs/related/22/C&F4Web.pdfand it looks like chapter 4 of Pappenfus' if I understand it correctly. Against current "wisdom" this states (page 104) that a properly
Hi Peter Chadwick kindly scanned the Pappenfus pages that I needed to make my math work.Now I am trying to extract the needed parameters from the characteristic curves to see what happens. However, i
All I was simulating (with LTspice) a three phase power supply where the secondary is in star configuration with full wave rectification. You can get also a second voltage from this by connecting to
Hi Gary, All I was thinking about your statement and looking a typical tube anode characteristics (curves).If I read this correctly, change in plate voltage does cause a change in plate current.Is th
Gary, ALL As far as I understand modulation, mixing and multiplication are just about the same thing. So, if there is an input port to an amplifier that changes the gain or in other words the output
All I am back on my 4CX5000 project and as it not done yet, I am still contemplating the circuit to be used.Earlier this year I got solid info from this reflector for GG operation and that look like
Hi Peter Looks like I should find a circuit to compensate for the high input C .I did build a GU84b amp and that uses a pi-circuit where the grid cap is on one side.Kind of sorts things out for 10, m
Hi No problem. I am also a somewhat seasoned amp builder and so far only one amp was tricky, that was because I had a near SECOND resonance on the plate choke chain and rf voltages can build up. That
Hi I have one of these heatsinks that have two 120 mm side by side and it is with the air flow chamber. The chamber is just an empty box about the thickness of the fans, in my case perhaps 35-40 mm.
All I have a home brew GU-84b amp that I don't seem to be able to sell so perhaps I keep it and upgrade a bit. The question is: Do stepping motors, properly used, big enough, etc. keep their position
Hi Thanks for the ideas. Does anybody have a good idea how to find the "zero point" on vacuum cap without adding a potentiometer for position feedback? I was thinking about reflective optical sensors
Hi I am going to use these same PSU, looked extensively on the WEB to no avail.If you find the documentations, please share! I saw plenty of pages where the connections were reverse engineered so the
This really looks interesting!However, could not get the installation script go all the way through on an old laptop with XP.Markku _______________________________________________ Amps mailing list A
If my memory serves me correctly: Is it not so that S11 refers to the input port "input impedance" of a two port network?So, in this case the input impedance is just simply about 1 ohm with small rea
All I have a GU-78 amplifier based on the Russian R-140 military station. It turns out that the efficiency is low on 160 m and I suspect that the tank circuit Q is low on 160 m. However I am not sure
All Thanks for the info. I know the G3SEK tool quite well. I believe the power measurement is close to OK, I have a bird and two other meters to check this and all show similar power values. I added