Amp people, Its an interesting discussion with lots of answers. I'll ask Reid Brandon, retired from Eimac/CPI, what he knows. I have a Henry 3K Classic that has not been fired up in years, that is a
There was a production issue related to Eimac and the two MRI equipment makers who used the 8877. I attached some information here that I got from another friend who worked in the tube biz then: ETO
Jim, you could subtract your meter lead resistance from each winding measurement, its even better. Also, notice that the value of R slowly dropped. This is because the secondary is resisting the step
Alan, I don't know the AL-1500 but It isn't likely that running the filament alone without HV will damage the filament of a 3CX1500A7/8877 triode - unless the filament voltage rose up too high, when
I use a R&S FSVR7 and Hp 8560E at work with big RF amplifiers, and have had a Tek 7L13, 7L14, Hp 8591E in my home lab over the decades. All of those boat anchors are gone now. My current favorite SA
It is best to contact the tube manufacturer for their recommended hi pot levels as well. For instance, on very large tubes, the hipotting of G1 to K may have a time limit, like a few minutes. For the
Hi Jim Good to see the 6m beast complete. I know it was fun. I have found one source of commercial ribbon wound and tubing RF inductors to be 1-5 kW medium wave broadcast transmitters. Johnson/Multro
Beware that the black epoxied Mica cylindrical capacitors are largely intended for broadcast band use, found in transmitters and antenna tuning units (ATU). They also can work in induction heating ge
Henry Radio designed their single phase HV power supplies for the 2K and 3K families of amplifiers using a single section L-C filter. But there is a special trick in that the 8Hy series choke is reso
I agree with what both Jim's replied to Alex P.s comment about trying to get reasonable input Z measurements using a VNA and a cathode-driven triode. Same is true of cathode-driven tetrodes, which I
I was looking for same thing Monday. API was bad enough but now Spectrums website is really sparse. I can't find any Sage products. Sucks when companies sell out and the new management doesn't realiz
I do not know of others. i have some short pieces also. Are you making a quantity of hybrids? I am wondering if some European or Far East company might have made similar. That stuff is all over solid
I thought there was.a design on QEX at one time. But maybe it was QST? There are some consumer microwaves that use AC/DC converters in switchmode. We have commercial 10 kW Glassman switchers at work
Yes, i remember the 2017 design. The earlier one, the 8877 amp with Watts Unlimited power supply, is likely not available anymore since Tim Hulick is SK. John K5PRO __________________________________
The inverter microwave ovens are lightweight and cheap. Panasonic made them originally. Solid state microwave ovens are expensive and few. Really expensive, thousands. Its hard to beat using a $15 tu
This discussion reminded me that been collecting plate transformers for many years. These are classic big iron so they would be heavier to ship than Heathkit or Dentron iron. I am interested in selli
There is still a lot of broadcast FM transmitters in the US and worldwide using CPI/Eimac ceramic/metal tetrodes and triodes. Only need installs and stations with the bucks can afford to buy a new SS