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

[Wes Stewart]

The actual return loss improvement is twice the attenuation, but I know Paul knows that.


--- On Wed, 4/21/10, Paul Christensen <w9ac at arrl.net> wrote:

> For the same concerns, I think an auto-switched pad engaged
> during an input 
> fault is a good idea.  In the case of the SPE amp, I
> would not like to have 
> 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.
> 
> The pad may assist with improving linearity from the
> driving transceiver, 
> but improving linearity can be accomplished with better
> efficiency if the 
> transceiver has an internal ATU with an auto-tune function
> that can be 
> programmed to limit the transceiver's power during the tune
> function.
> 
> Paul, W9AC