Here is an idea that one could use :)
Instead ZENERS use a DC amplifier offset to the voltage you need for the
proper tube biasing. Now you can add audio to it and you have created an
XCELENT AM transmitter :)
Alex, properly biased :)
> -----Original Message-----
> From: amps-admin@contesting.com [mailto:amps-admin@contesting.com]On
> Behalf Of Phil Clements
> Sent: Thursday, July 18, 2002 11:03 PM
> To: 2; Steve Katz; wa5jci@flash.net
> Cc: AMPS; Douglas R Snowden
> Subject: Re: [Amps] Bias Zener Diodes In Parallel ?
>
>
>
> > The problem with a 50w zener is that its Vz is not adjustable. A
> > fwd-biased Si diode string can be adjusted by changing taps.
>
> I never found it necessary to "adjust" the bias. I use 50 watt zeners
> to obtain the correct ZSAC, and it stays there. I use 8 volt units for
> an 8877 with 2500-3000 volts Ep and a 12 volt unit for 4kv Ep. If I
> want to cut ambient heat when on CW, I just switch to another 50 watt
> zener of the proper value to lower the ZSAC to an appropriate value.
>
> IMO, "strings" of components, marginal tank components, non-RF rated
> capacitors, and 3-4 tubes are only found in amateur equipment.
>
> To each his own; I am just not a "Rube Goldberg" type when it comes
> to amp building!
>
> (((73)))
> Phil, K5PC
>
>
>
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