[TowerTalk] VSWR Changes with Power

[RCM]

> On Oct 21, 2019, at 18:37, ed_richardson at shaw.ca wrote:
> 
> 
> I did some more testing today and found out the there are indeed out of band oscillations that are occurring.  They did not occur everywhere in the band, only when the antenna load was slightly inductive +9<X<+3. 
> 

You note that you get no oscillation at full power, then funny stuff at low power.

I’m a bit thin on solid state amps, so I try a possible tube amp idea and terms.

Tube amp tank circuits are designed for a particular plate voltage and plate current, hence plate load impedance.

Tune up at high power for the designed Zp. All is happy.

Drop just the drive, for lower power, and the tank circuit and input circuit values are out of the park.

That plus some other weak component (L connector) might be the cause.