[TowerTalk] Tower and antenna decisions

[Jim Brown]

On 10/26/2013 12:34 PM, Richard Solomon wrote:
> That just shows the failings of SS Amps. A 1.3:1 SWR equates to 1.7%
> reflected power. Any
> Amp that can't handle that has no place in my shack.
>
> As for tube amps, just shows the benefits of a tuneable Pi-Network.

My neighbor K6XX, the engineer at Elecraft who put the KPA500 into 
production and has done extensive testing of many competing amplifiers, 
observes that the IMD produced by a solid state power amplifier rises 
rapidly with a mismatched load, and also when operating too close to its 
limits.  To prevent this, the firmware in the KPA500 limits power 
output, and also causes it to fold back with SWR around 2:1.  Both of us 
run tube amps for contesting.

73, Jim K9YC