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[AMPS] 8877 bias curve?

To: <amps@contesting.com>
Subject: [AMPS] 8877 bias curve?
From: 2@vc.net (2)
Date: Fri, 2 Nov 2001 05:54:18 -0800
>
>Hi folks,
>
>Doing some tinkering here, I worked out a polynomial based on
>Eimac's GG constant current curves for the 8877 to calculate static
>plate current based on a given bias voltage.  Does anyone have
>any data they'd be willing to share based on real measurements?
>I'd like to check my work, to see how far off it might be from
>a real case.  The Eimac data is spotty at higher plate voltages,
>(thus not a lot of points) although the curve fit seems pretty fair.
>
>Here's a sampling, based on a constant plate voltage of 3900:
>
>Bias (V)       Plate (ma)
>------------------------
>19.4           Cutoff
>18.0           18
>17.0           33
>16.0           51
>15.0           70
>14.0           92
>12.0           142
>10.0           198
>8.0            262
>
>Does this look anywhere close to real?
>
/   As I read it, 8.2V of cathode-grid bias produces c. 185mA of ZSAC.  
However, even at 90mA of ZSAC, an 8877 is so much cleaner than today's 
transceivers, it would make
virtually no audible on-the-air difference in IMD.  

cheers, Jim

-  R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.  
end


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