[Lf] Top Loading Vs. Base Loading]

[Andre' Kesteloot]

Mitch Powell wrote:

> >From the Sept 1995 LOWDOWN, Bill Bowers had an article
> directly related to your question:
> TOP LOADED ANTENNA
>
> I summarize here  :-)  , he set up a temporary antenna near
> the shop and experimented. Vertical was 36 ft (4 #14 AWG
> wires spaced 12") and top hat was 4 ft x 38 ft of 8-#14AWG
> wires spaced 6 inches. Copied occasionally 80 mi. away on
> low noise days.
>
> At that point he conducted tests by inserting a loading coil
> between the vertical wires and the top hat noting a
> significant increase in signal strength "even though there
> was only a very small increase in antenna current."
>
> The loading coil (2.2 mH Q535 wound with Litz wire and
> having Amidon 33 rods included) was suspended on the top hat
> bus bar and connected in between the bus bar and the
> vertical wires.
>
> It was then necessary to reduce the antenna tuning coil from
> 2.65 mH to 1.2 mH.  The radiated signal increased and
> reception increased to 130 mi., with the 80 mi rcvr copying
> on a regular basis.
>
> Quote"It is interesting to note that even though there was a
> significant increase in signal strength there was almost no
> increase in antenna current ??"end quote
>
> He suggests more investigation, and requests any info.
>
> Les, I hope this information is what you were looking
> for.... and not knowing if you had this particular issue I
> amd sending it along ( greatly edited - with apologies to
> Bill !! )
>
> By the way Lyle also did an extensive report on Transmitting
> Antennas Page 29 Dec 1993..... and shows apparent benefits
> of center loaded transmitting antennas.
>
> 73
>
> Mitch VE3OT