[Amps] Old Transmitter designs (was cathode driven/groundedgridmagic revealed.)

[Gary Schafer]

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Bill, W6WRT
> Sent: Wednesday, July 22, 2009 10:23 PM
> To: 'Ham-amps'
> Subject: Re: [Amps] Old Transmitter designs (was cathode
> driven/groundedgridmagic revealed.)
> 
> ORIGINAL MESSAGE:
> 
> On Wed, 22 Jul 2009 22:04:59 -0500, "Gary Schafer"
> <garyschafer at comcast.net>
> wrote:
> 
> >You disagree with Bill Orr?
> 
> REPLY:
> 
> If Bill Orr is recommending a resistor to "swamp out" load variations over
> the
> RF cycle in a tube's input circuit, then yes, I disagree.
> 
> A resistor can not store energy during the high impedance part of the RF
> cycle
> and then return it during the low impedance part. A parallel resonant LC
> circuit
> can, given sufficient Q. The circuit can be either a pi-net or a simple LC
> parallel resonant circuit.
> 
> 73, Bill W6WRT

You misunderstand Bill. We are not talking about a tuned circuit at the
input of the grounded grid amp. We are talking about what effects the
varying load has on the driver. If the driving source has a low enough
impedance as seen by the amplifier then the varying load provided by the
amplifier will have less effect on the driver. The load change is then a
smaller percentage change for the driver.
I did not imply that swamping the exciter was better than a tuned circuit at
the input of the amp.

73
Gary K4FMX