On Fri, 25 Jul 97 21:42:03 -0700 Rich Measures <measures@vc.net> writes:
>>
>>On Wed, 23 Jul 97 19:15:00 -0700 Rich Measures <measures@vc.net>
>writes:
>...snip...
>
>>I built quite a few one and two 4-1000A amps in AB2 that were quite
>>clean. The key was regulated bias and screen supplies.
>How much screen V?
500V when the Ep was down in the 4500V range. Up to 750 at 6KV.
How much grid current?
That was 30 yrs ago, I dont remember all the details. It was in the
wiggle range on SSB peaks.
How did you regulate the
>grid
>bias V?
The standard 6080 or 6AS7 regulator circuit that was common then.
> - Did you measure the IMD yourself, or did you accept on the air
>reports?
Heck no. Back then on the air reports were sufficient. The majority of
the exciters were extremely clean and anyone with a dirty signal was
told VERY quick. I built these amps for others and can remember hearing
many on the air. They sounded fine. I quit building them in 1967 when I
got married. Couldnt spend all those late hours and weekends at National
Radio any more. But it was fun while it lasted.
>>...... What
>>would the distortion difference be between AB1 and AB2? I do not
>know.
>>
>>73....Carl KM1H
>>
>It depends on how much grid current you run. For example, with 1000V
>on
>the screen, 7kV on the anode, and 0mA of grid current (Class AB1), the
>
>4-1000A/8166 is fairly linear. If the grid current were increased to
>0.05mA, technically speaking the amplifier would be running in Class
>AB2---and it would still be fairly linear. However, if the grid
>current
>was 5mA, IMO, there would be a substantive decrease in linearity.
...
>...
>Eimac does not list the 8166 for Class AB2 linear service.
So What!
They dont list it in GG either in any official spec sheet. It was only an
after the fact newsletter.
73....Carl KM1H
>Rich---
>
>
>R. L. Measures, 805-386-3734, AG6K
>
>
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|