Why the heck not? People I know runing G2DAF amps do sound much better and also have less bandwith then big time prominent hall of fame contesters using Alpha/Ameritron amps and latest so called stat
You are not telling us the truth. Running substantial grid current in grid-driven amps makes feculence as surely as the sun rises in the East and sets in the West. On the other hand, for clearing a
No never give up, do you? Rich. Again: " the proof of the pudding is in the eating.......". It has been proofed many times that the DAF works and that is what counts, right? sooner............ de Han
[snip] Please, let's not start that empty argument again! Neither of you is saying anything new. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) http://www.i
I agree that the DAF config. works, Hans. The total distortion level produced by the three DAFs I ''proofed''/measured was no better than 22 db below PEP. As long as one stays c. 25kHz from the amat
Although I will NOT take part in any further meaningless argueing about this circuit, I´ll make the following statement: Still using it! Me and my ham-collegues, still happy! Still working on n
But if you swamp the grid with 50 ohms, the additional load by the paralell grid drawing current is much higher and causes no clipping? de Hans -- -- FAQ on WWW: http://www.contesting.com/ampsfaq.htm
Not wishing to discuss the G2DAF circuit any further, I still want to question your statement regarding substantial grid current causing distortion. I do not think that is necessarily true. The tube
Eimac makes two tetrodes that are designed to draw grid current in linear service --the 4CX1500B/8660 and the 4CX600J Typical grid current is less than 0.5 mA in either. // Is the data sheet for the
Still on the river excursion in the Land of Pharoahs. - Rich..., 805.386.3734, www.vcnet.com/measures. end -- FAQ on WWW: http://www.contesting.com/ampsfaq.html Submissions: amps@contesting.com Admi
I have a feeling that a lot depends on the tube(s) used: effectively, they have to be very linear as a screen modulated AM tube at the PEP output required. 73 Peter G3RZP -- FAQ on WWW: http://www.co
Or if the regulation of the RF drive voltage was poor, or if the grid bias shifted when grid current was drawn. if I think the answer to that is that distortion is reduced in gg because of negative f
Most of that style amplifiers are actually using the very peculiar Philips QBL 3.5/5000 that leads to say much bigger amplifier, two times or more, than the standard amateur market Alpha's or Ameritr
Some tubes won't tolerate grid current, while many will. There are dozens and dozens of tetrode types that can be run with a small amount of grid current, and will give very good IMD performance. Th
Hi Peter, There are a number of problems with shifting the operating point around. 1.) Phase delay. If you filter the rectifier that samples the input signal, phase delay is introduced. There is no
Tom has some very good points. Personally, the G2DAF is not an approach I would use, but it can be made to work. My feeling is that some tubes work better in that circuit than others; the screen grid
Can you accept what is on the constant-current curves? I do not agree. Modern transceivers need a 50-j0 ohm load. With grid current, the load Z on the exciter goes bananas later, Peter - Rich..., 80
With the exception of the 4CX1000A's 0w grid rating, all tetrodes will tolerate some grid current. The constant current curves show why you don't want any. The 4CX1500B and the 4CX600J are two tetro
Yes - but what has that got to do with it? Quote again from Pappenfus et al. 'Most power tubes have a more linear plate characteristic operating Class AB2, however.' grid Not necessarily so. It depen