Did anyone figure out how to use a modern Op-Amp (not 748) in a mosfet shunt stabilizator for a tetrode screen power supply? This is what G3SEC said in his original article: "This is a very high-gain
Thank you Jim. Also Roger - W7TZ. You both show an arrangement I haven't seen before. Most likely I'll use it. _______________________________________________ Amps mailing list Amps@contesting.com ht
Hi, Could someone please confirm the output impedance of a classic tetrode linear amplifier does'n change as plate voltage sags or swings? I imagine it must be the same because no tetrode amp design
I've built an amp roughly based on the Pa0fri design (with some changes that include better stabilisator for the screen voltage - thanks to this group, 3000V - under load, HV PSU from an old R-140 mi
Hi, I've built a GU-43B based amp roughly following Pa0fri design (shown here https://pa0fri.home.xs4all.nl/Lineairs/Frinear1500/FRI1500eng.htm) My modifications are: better PSU for the screen(thanks
Why? Privacy online is important. Anonynymity should be the default. This is a public mailing list and I signed up with my non-identifying email address that has 3 decades of information floating abo
Thank you for your reply. I'll calculate this. I was considering adding a small (12pF) series capacitor that would be shorted on all other bands than 10m. Are there some hidden dangers with this idea
not to my problem, but the Pi-L values for the plate capacitance are lower Pi L2-Less values. On default settings the pi-L circuit also shows much lower plate capacitance for the Pi-L network. Furth
Could you let me know where is it discussed, please? (the ham radio handbook by Orr? I've read it multiple times, but I don't remember that). I've added a coil in series that was stretched/compressed
I obviously meant the tube and socket is 27pF not uF. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
A quick question, does anyone on this list have a working amplifier that gets to it's rated output on 10m with a grid driven tetrode with no neutralisation? If so, can you post a picture of its pi ta
Thanks for the understanding. Coming back to the subject. After reading quite a bit, calculating various things, looking at various tables, ripping half of my amp out and rebuilding I still don't qui
That amp was good for more than 1500w on all bands. There are many commercial and homebrew amps using tetrodes that can do this. This is very good to know. Neutralization isn't relevant to the proble
the case wall, as it has a big cap on the end. Just moving that thing 7cm away took 5~6pF away, then there are these large metal holders, just reverting them so they face away lowered it by further 2
A quick question. How does one know if one's tube requires parasitic suppression? Is it gain dependent? (high gain = needs suppression, low gain = doesn't) I was following a published design that had
My father used to do this kind of work decades ago so I know how it is done. Rewinding is not difficult (as long as we're not talking about toroids). But what sometimes is very difficult is to disass
Now that you say it that way I start suspecting the auto transformer. Assuming nothing is miswired (and I have to rewire anyway to route the wires nicely - currently it's only a "working" setup) it i
I decided to replace the auto transformer arrangement with a custom wound 230 - 2*130V transformer. Could someone please verify J chose the voltage correctly, please? I need 350V at 45mA max. The shu