Doubling the HV will demand changing of many capacitors and the Pi net parts. But at 1200 V a pair of GI7B will put out 400 W, three - 600 W. The original Pi net will do the work. 6KG6/EL519/6P45S is
Will, The sections will be put in series by the common rotor. Each of the 2 stators ends will be capacititor's end. The rotor and the frame will be insulated and will work OK. Have done that. 73, Val
This probably is connected with the possibility of using switching mode power supply on the filament xmfr's place. There are a lot of such transformers manufactured for feeding 12 volt halogen bulbs
Actually GI6B is a triode too. Although there is no substantial difference, GI7B is considered to be better. 73, LZ1VB _______________________________________________ Amps mailing list Amps@contesti
Hi David, There is a GLA-1000 conversion to GI7B. It keeps the most of the amp - tank etc., as it's for HF, but GI7B is perfect for 6 and 2M too. 73, Val LZ1VB I've got old Dentron GLA-1000 sweep tub
Hi Peter, Well, the output of a pair GI7Bs at 1100V is 400-500W. I think that we will need three for the same power at 900V. 73, Val LZ1VB _______________________________________________ Amps mailing
Don, How the bleeder resistor would help, if the reverse current exceeds 37 mA? At 325 V screen voltage this makes 12 W - the maximum screen dissipation. I have seen many brand new tubes with much hi
Mike, Thank you very much for the explanation. I completely agree. The question is how a tube, showing maximum reverse screen current leading to an excessive screen dissipation could be used in an am
Bill and Ian, Thank you for the enlightening of the question. Than do we need the screen current protection to trip by the reverse current and at what level? For 4CX1000A the circuit trips now at +/-
The percentage of QRO deprived remote stations is much lower. There are some other legal limit amplifiers which are happy to run remote. ACOM 2000A for one. 73, Val LZ1VB ___________________________
David is right. 4CX1500B seems to be just 4CX1000A with declared 500W extra dissipation at the expense of the air flow. The grid and screen however are same - very fragile. That's why it can't produc
Sam, I'm sorry to be so late with this topic, but you might be interested to know that there is a solution on the market http://www.acom-bg.com/amplifiers3x2000.html, that answers your questions. 73,
Jim, ACOM1000 and ACOM2000A are without doubt the most popular amplifiers based on GU74B. Many thousands of them are working under the following conditions at1000W output: Plate 2350-2400V Screen 340
Paul, You are absolutely right. I omitted the standby state as I think that Jim doesn't care about it. 73, Val LZ1VB Val, For the sake of completeness, I believe the typical "three state" bias voltag
Carl, The 800W labeling of GU74B wasn't fraudent, but a pretty fair. If this tube was designed by EIMAC, or other western company it would have been undoubtedly labeled 4CX800. Compare its size, grid
Yes Peter, Please find attached a scan of the GU74B page of the official Svetlana product cathalog for 2004. 73, Val LZ1VB Corrected by Svetlana? Please send a copy of the revised data sheet of the G
I think that the only right word that can be used in this sentence is "always". Having seen Svetlana's quotation I think that it's hardly likely a ham will buy a factory new GU74B. 73, Val LZ1VB The
Krish, There are still plenty of GU-74Bs around. Yes, the price is higher than before, but it's still cheaper than 3CX800A. I see no cheaper or more popular tube that could be easy transplanted there
Farnell carries genuine Molex. I have ordered pins and housings there, though only the 4 pin kind that is used by the new radios. Could check the PN in Monday. 73, Val LZ1VB So our best bet is to ord
Pete, Array Solutions services ACOM amps in the USA. The emails with technical questions to the factory never remain unanswered. Your friend could explain his problem to acom@acom-bg.com 73, Val LZ1V