[Fwd: LF: GW4ALG Vertical]
Tue, 19 May 1998 11:14:53 -0400
Steve Rawlings wrote:
> Dave, G3YXM wrote:
> >Nice to work GW4ALG for the first time at the weekend. What was the
> >vertical Steve? It was the best of the two with me by 4dB or so.
> Although the 200 ft single-turn loop (described in Technical Topics, May
> '98 RadCom) works well for stations in line with the loop (east-west), I
> had a feeling that it wasn't getting out very well to the north or to
> the south. The new addition of a 40 ft vertical has proved this, and is
> doing a good job of filling in the gaps. New signals heard for the
> first time using the vertical include the 'helicopter/running horse
> noise' (Loran to the south?); and G3PLX to the north.
> My 40 ft vertical is installed on the gable-end wall at the back of the
> brick-built house. The lower coil is wound on a plastic bucket located
> 10 ft above ground. The wire at the top of the lower coil goes up and
> then through a hole in the wall into the loft [attic] . . . through a
> variometer (using another bucket as outer; a short length of [not
> previously used] toilet waste pipe as rotatable inner) . . . through a
> good many turns wound on a plastic laundry basket, and out again through
> the same hole in the wall. The wire then goes up to a 1.2 mH loading
> coil (wound on plastic [gutter] downpipe) mounted on a wooden support.
> The top of the 1.2 mH loading coil is connected to 15 ft of aluminium
> pole - also mounted on the same wooden support.
> Outrigger wires (spaced about 1.5 ft from the aluminium pole) and a
> small capacity hat attempt to increase the top capacitance, but there
> are no top hat wires (there being no suitable supports). All coils are
> positioned in the vertical plane. The lower end of the bottom coil is
> connected to the outside water tap. Space problems mean that the
> aluminium pole has to support the centre of the delta loop too - and
> yes, there is definitely interaction between the two antennae.
> The major problem with my vertical is achieving enough insulation -
> there's a lot of volts up there, even when just running 15 W of RF.
> So, unlike the standard 'tee' configuration, I've had to grapple with
> compromises of mechanical stability (supporting the 15 ft pole); and
> electrical insulation.
> As previously reported by Mike, G3XDV my garden is only 50 ft long at
> the back, but I can use a tree in the front garden to support one end of
> the delta loop. [Was g-r-e-a-t to have worked you Mike at the
> weekend, running just 30 W to my loop - 173 km - WOW!]
> Don't let anyone say they can't work VLF because their garden is too
> Regards to all,
> Steve, GW4ALG