[Lf] Still learning...

[Andre' Kesteloot]

Dave wrote:

> Last night whilst the tx was sending a QRS call on 71.8 I went outside to
> check that there was no corona discharge from the antenna, easy to see in
> the dark.
> No problems were seen but I noticed a crackling noise behind me. Closer
> investigation revealed that it was coming from the ground at the base of the
> antenna support mast which is strapped to a fir tree. Small sparks could be
> seen amongst the undergrowth where the mast touched the ground. This was
> obviously a waste of valuable energy!
>
> I decided to earth the pole, then at least it would no longer be a lossy
> structure, just some additional capacitance. After I had done this three
> things happened, the resonant frequency went down, the match changed and,
> when the ATU was re-adjusted, the antenna current rose by 10% for the same
> power input. This must be due to higher Q because of less loss.
>
> Well worth doing. Fire-risk reduced and power increased!
>
> Look out for lossy structures near the antenna and either insulate them
>  they will then be live... ) or earth them solidly.
>
> 73, Dave G3YXM.