[Elecraft] attenuator in amp was Re: K3 and Expert 1K-FA

[Paul Christensen]

Yes, that's right, 3 dB per trip to and from the load.  Not 3 dB in total as
I indicated.

Paul, W9AC

----- Original Message ----- 
From: "Tom W8JI" <w8ji at w8ji.com>
To: "Paul Christensen" <w9ac at arrl.net>; <elecraft at mailman.qth.net>
Sent: Wednesday, April 21, 2010 7:05 PM
Subject: Re: [Elecraft] attenuator in amp was Re: K3 and Expert 1K-FA


> 30-watts dissipating as heat in the front end of the amp. The 3dB pad does
> improve return loss into the amp input by the same amount. But, the
> effective gain factor of the amp is then reduced by 3dB.>>>
>
> A 3dB pad gives 6 dB return loss. For example if load SWR is 2:1 (5.5dB 
> RL) and we add a 3 dB pad, return loss is 9.5 dB (1.4:1 SWR).
>
> A 3 dB 50 ohm pad with an open circuited output looks like 150 ohms. You 
> can make a 3:1 SWR test fixture by opening and shorting the output.
>
>
>
>