Rich Measures wrote:
>
>>
>>
>>
>>On Sat, 19 Dec 1998 07:47:30 -0800 Rich Measures <measures@vc.net>
>>writes:
>>>>Since you believe what is published Rich ( when it is convenient )
>>>how
>>>>come you cant agree with published Eimac results?
>>>
>>>Ä Eimac said that linearity improved when the anode supply voltage
>>>was decreased from 2000v to 1500v?
>>
>>Yes, thats what several of us have said the past few days.... Its right
>>in the full spec sheet.
>>
> In one test the ZSAC is 0.133A. In the other test, the ZSAC is 0.07A.
That is one of the problems with the "typical" data sheet operating
conditions - all the important parameters tend to change together: anode
voltage, screen voltage, ZSAC (and therefore grid bias), RF drive level,
peak anode current and expected power output. They all have an effect on
linearity, but they all get mixed up together in the recommended
"typical" conditions so that it's impossible to isolate the effects of
any individual one.
I still tend to believe that any tetrode will become more linear if you
increase the anode voltage to give more available voltage swing above
the screen voltage (and then operate the tube in a way that takes
maximum advantage of that change).
However, I don't want to re-open that argument with Carl, because
several months ago we agreed to differ until some valid comparative
measurements could be made. By "valid" I mean holding constant as many
of the other parameters as possible, and changing only the one whose
effects you want to observe.
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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