[Lowfer] Another Antenna question

[pete at pcranwell.com]

Bill,

I live in the mountains of Va.  When I stamp my foot, the depression fills
with water.

In an earlier ant experiment (on 75 meters), I loaded a 30 foot whip with a
loading network that put the feedpoint electrically above ground.  The
efficency was much higher than with loading coils at the base.  In actual
operation the receiving stations could not tell the difference when I
switched between the vert and my windom.





------32ft--------LOADINGCOIL--16ft---
                  LINK
                  C
                  O
                  A
                  X

The 16 foot radials (2 of them) were grounded on the end, but only barely.
The loading coil was at the base of the 30 foot section and the link
coupling was at the hot end of the loading coil (Close to the 30 foot
section).

I used the MFJ fiberglass pole with a piece of wire for a radial.  It's my
ARES antenna and works as well as my permanent wires.

I think the same approach might work for 1750.

Pete Cranwell
WA2EIN
Formerly Beacon "P" back in 1968



-----Original Message-----
From: lowfer-bounces at mailman.qth.net
[mailto:lowfer-bounces at mailman.qth.net]On Behalf Of Bill Ashlock
Sent: Thursday, May 29, 2008 2:35 PM
To: Discussion of the Lowfer (US, European, & UK) and MedFer bands
Subject: RE: [Lowfer] Another Antenna question




Andy,

You have raised some good points and Jay's suggestion that you check out the
URL he gave you is a good one. One item you didn't mention is ground losses,
and at 1750M it is probably the most significant portion of vertical antenna
design to be considered..... And be careful not to fall into believing that
your ground conductivity is the same as any author's ground conductivity -
especially when comparing the typically good mid-western US ground
conductivity with the poor eastern US ground conductivity (not to mention
'mountainous' ground conductivity where there is almost no conductivity at
all!). You will find the ways to reduce this loss will vary according to the
ground composition, whether it will be by using ground stakes, buried
radials, surface radials, well casings, or my favorite for very poorly
conducting soil, the elevated set of radials, AKA the counterpoise.

Good luck on this. You should find LF antenna design to be both fascinating
and rewarding.

Bill

> From: jrusgrove at comcast.net
> To: lowfer at mailman.qth.net
> Subject: Re: [Lowfer] Another Antenna question
> Date: Thu, 29 May 2008 11:45:45 -0400
>
> Andy
>
> A good source of study material to provide answer to your questions can be
> found here:
>
> http://www.strobbe.eu/on7yd/136ant/
>
> Jay W1VD WD2XNS WE2XGR/2
>
>
> ----- Original Message -----
> From: "KU4XR"
> To:
> Sent: Thursday, May 29, 2008 11:14 AM
> Subject: [Lowfer] Another Antenna question
>
>
>> Hello Fellow LOWfers:
>>
>> I would appreciate any experienced input on some vertical antenna issues
>> for 1750 meters. " Using a vertical wire with top hat "; which would
>> radiate
>> better; a shorter vertical with longer top hat, or longer vertical with
>> shorter top hat ?? I would assume that the more wires you can include in
>> the top hat, the better the RF will reach the top and radiate. Is this
>> assumption correct or not ?? Has anyone tried hellically winding a
>> section,
>> say 20 feet ( bottom , middle , top section ) so the overall heigth would
>> be
>> a more one man manageable 30 feet ??. A realistic and do-able antenna for
>> me
>> would be a 20 foot vertical with a 30 foot top hat which can include many
>> wires
>> in different directions ( a capacitance issue only I'm sure ).
>> Would ground losses be more evident with a top hat version, or the
>> straight vertical ?
>> Any input will be valued and appreciated:
>>
>> 73, from Andy Bell - KU4XR - EM75xr
>>
>>
>>
>> _______________________________________________
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