[Elecraft] (K3) SWR Consistent - low or high power

[Brian Alsop]

Some of this effect hqs to do with the reflected power diode.
Depening upon the sense circuity, the reflected power diode may not see 
enough voltaqe to be fully conducting.  Thus it reads less current in 
the reflected position and hence lower SWR that at higher powers.

Also the type of diode used is important.  I believe the K3 use Schotky 
diodes which conduct at lower voltages than say silicon diodes. 
Germanium diodes are even better but fragile and harder to get these days.

73 DE Brian/K3KO




Tom Boucher wrote:
> My theory in these cases is that it's nothing to do with bad antenna connections, but more due to the rig putting out a higher harmonic content at higher power levels. The SWR meter sees a bad SWR at the harmonic frequency so the reading is slightly worse.
> 
> 73
> Tom G3OLB
> 
> N3OI wrote:
> <*One observation:* I use low power to set SWR with my TenTec manual tuner.
> My FT-920's SWR meter would usually shift a bit when I increased power to
> 100w and I would then quickly tweak it back down.  With the K3's SWR meter
> (no ATU installed), after setting the tuner at 10w or so, the reading stays
> the same when power is increased to 100w.> 
> 
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