That works until it doesnt and then creates a nice wild plasma arc. That is something to watch!! Carl I always thought the way to make a h.v. fuse was to bolt a pair of ceramic standoffs in a conveni
A couple of thoughts What is the gettering/regettering process of that particular series of tubes? An arc is often caused by internal gases released when the tube is overheated. Are you using a True
That is the correct way Roger, just peak at a low Isg using sufficient drive for rated power. As the tube ages increase Isg. I have been doing that with tetrodes from the 4CX250B/8122 to ones with ha
"Yes, anode tuning must be for maximum screen current with the anode capacitor and loading capacitance for maximum output power and screen current limit" That is not correct, see my prior post. Carl.
Viewstar was a Hammond of Canada product. B&W bought the PT-2500 and then had to redesign the tank circuit which arced badly. It worked well but like all things B$W it was overpriced and only a run o
The world doesnt revolve around the Ameritron choke which took 3 tries with hams as guinea pigs before JI got it right. See what the rest of the world is using and if you dont need 12M there are easi
Ive had no problems from squeezing the Ameritron choke into Alpha 76/78's etc which is about as tight as you can get. Carl mounting schemes work. Typ vert mounting is used. Either way B+ has to be fe
It is 200W period in the USA, no SSB or AM allowed; only CW, and data. I have no idea if my 76PA works there and dont care either. As far as 160 Ive put that choke in several Amp Supply LK-800A's as
The Alpha doent have the luxury of all the room in a Henry 8K which used that configuration. A B&W 802 works 160-10 including WARC even in a souped up Alpha 77SX with the external transformer but don
Well, 4KW PEP on AM might be pushing it! Where and how a plate choke is mounted mostly has to do with making the best use of chassis real estate and heat dissipation. Someone mentioned that the famou
Try unwinding a turn and leaving it float and see if the resonance moves up. Try another turn. Reconnect as original if no improvement. Carl Carl, Did you notice any effect on 10MHz. When I put an Am
I should have said remove wire from bottom of choke. Carl <Carl, <Did you notice any effect on 10MHz. When I put an Ameritron choke in my <78, which I agree fits just fine, it was okay but went bang
Apply a very fast 12VDC between the grid and filament pins. Ive had a better than .500 batting average with tubes that werent gassy to start with. Carl No I can't see that. The tube "looks like" an E
Maybe the difference between success and a display tube. Herb nailed it on the first try. Carl "Apply a very fast 12VDC" What is the difference between a fast 12VDC and a slow 12VDC? I missed this al
The problem with that and some other Russian triodes is that they are low mu and make poor SSB amps with poor IMD. Running in GG takes a lot of drive and HV for reasonable effficiency. They make nice
Heyboer has done several rewinds for me over the years plus replacements for a few others at far less than Dahl at both locations. There is another rewinder down in hillbilly land that does a lot of
As a First Radiotelephone holder since 1956 and currently keeping a vintage Bauer 707 running on the BCB I certainly agree. That TX uses PP 4-400A's for RF and Audio and tetrodes/pentodes are NEVER u
The "Gold Standard" tube is the 3CX3000A7 which has about the best IMD even at full HV. Throttle down to a mere 3000W and it defies detection on the bands. A 100W rig will drive it to a loafing 1500W
I woke up one day and it was gone! Carl -- This email has been checked for viruses by AVG. https://www.avg.com _______________________________________________ Amps mailing list Amps@contesting.com ht
The 8877 is only as good as the amp designer AND the user. You guys are the high end exceptions! Many want to push them well beyond 1500W, have poor to no protection, never do PM such as vacuuming th