Re: LF: LF daylight test close to the north hemisphere solstice

[DK7FC <selberdenken@posteo.de>]

Hi Luis,

No, i just mean a second transformer between PA and the other 
transformer, into the coax line. A simple 1:1 ferrite transformer.
Your ground conductors into and arround the building are a part of the 
antenna, obviously causing a high voltage between that ground and your 
shack ground. All you can do is reducing the coupling impedance 
(capacitive) and the electrical field strength. A well dimensioned 1:1 
transformer will provide a good decoupling and low losses. The improved 
decoupling may change the resonance a bit (because your shack earth is 
less a part of the system taking RF currents), so a retuning is 
required. Hopefully your shack earth is not the dominant part of the 
antenna ground :-) The less it is a part of the ground system, the less 
is the detuning of the antenna when inserting the second transformer.
73, Stefan

Am 04.06.2019 10:59, schrieb VIGILANT Luis Fernández:
> > This week I should have to rework the PA output transformer. The one
> > in use lacks good isolation and get arcs when pushing it a bit. All
> > going Ok may be I can still rise some dB