[Lowfer] WA2XRF back on the air

Andre' Kesteloot akestelo@bellatlantic.net
Mon, 21 Jun 1999 20:25:31 -0400


Thanks, William, that looks about right
Andre'

William Cantrell wrote:

> As a rough guess, you should have about 1000Vac rms times SQRT(150) across
> that coil, based on best-case LowFER calculations.  That would be about 17
> kVpeak, assuming the Q of the coil is over 700.
>
> Andre' Kesteloot wrote:
>
> > LF Amigos
> >
> > The AMRAD Beacon WA2XTF is back on the air on 136.750 kHz,
> > transmitting continously (7 days a week, 24 hours a day) at 5 wpm:
> > VVV DE WA2XTF/6 WA2XTF/6 QSL N4ICK AT AMRAD.ORG AR  (followed by a ten
> >
> > second dash )
> >
> > Maintenance was required on the antenna tuning unit, which consists of
> >
> > a large variometer (8-11 mH). The variable coil is electrically and
> > physically located between the two equal halves on the main coil.
> >
> > Because of the power (150 watts RF) and the inductance involved, we
> > have some serious RF voltages at that point. An arc decided to
> > establish itself between those two halves, thereby short-circuiting
> > the variable coil, and thus modifying the total value of the
> > inductance at the bottom of the "T" antenna.
> >
> > 73
> > Andre'  N4ICK