[TowerTalk] 80-m. Inverted Vee vs. Dipole Performance

[Al Williams]

what is a half sloper? is it a half inverted vee (which is a sloper)?

k7puc


----- Original Message ----- 
From: "Tom Haavisto" <kamham69 at gmail.com>
To: <RLVZ at aol.com>
Cc: "Tower Talk" <towertalk at contesting.com>
Sent: Wednesday, September 15, 2010 8:53 AM
Subject: Re: [TowerTalk] 80-m. Inverted Vee vs. Dipole Performance


I have an inverted vee installed on a 48 foot tower - apex is around 45 
feet.
On another (64 foot) tower, I have 2 half-slopers - one for phone, one for 
CW.

I have found the half-slopers work very well working DX, and have been
my primary 80 meter antennas for a number of years.  Also work well
for working North America

I installed the inverted vee about a year ago so I could do some A/B
comparisons.

Working DX, the slopers are far better.  i was listening to a local
about 30 miles away running QRP.  He was about S2 on the sloper, S9 on
the inverted vee.  For most of my operating, I end up using the
sloper.

One thing I also did was to install a number of radials around the
tower with the slopers.  For a relatively simple antenna, it works
very well.  Given a choice, the inverted vee would be the first one to
go away.

Tom - VE3CX




On Sat, Sep 11, 2010 at 1:56 PM,  <RLVZ at aol.com> wrote:
>
> Hi Guys,
>
> I'd appreciate your thoughts and recommendations on the following 80-meter
> antenna setup:
>
> I operate portable from a QTH in Wisconsin for several weeks each year.
> This site has a short 50' tower, a small Hy-Gain TH-3 Mk3 Tribander on 
> top,
> and non-conductive guy wires. For a 80 meter antenna I've been using an
> Inverted V with apex at 47' and the ends at 15' above ground. This 
> 80-meter
> Inverted V seems to work pretty well on Stateside q's and fairly well on
> DX... but I've never done an A/B comparison with another antenna to 
> compare
> results. I base my results on how well it busts pileups in contests.
>
> Thought: Most people I've heard of who have modeled Inverted Vee's
> typically say "the Inverted Vee is a poor performer" and "you're much 
> better off
> with a flat-top dipole". But a few people contend that an Inverted Vee has
> some vertical polarization which lowers the angle of radiation. So in
> this case, if the flat-top dipole was at 47' (less than a quarter wave) it
> would still be a cloud warmer.
>
> Question: Since the flat-top dipole at 47' would be a cloud warmer, it
> seems to me that even if the Inverted Vee only had a very small amount of
> vertical radiation that the low Inverted Vee could perform as well as or 
> better
> than the low dipole on qso's over 1,000 miles. Do you agree that the low
> Inverted V might outperform the low flat-top on q's of a 1,000 miles or
> more? If anyone has done A/B comparisons on a low Inverted Vee vs. a low
> flat-top dipole please share the results. I am thinking that modeling 
> software
> may not give the Inverted Vee any allowance for vertical polarization...
> which could be why they often model poorly.
>
> I'd really appreciate it if anyone had A/B comparison information you
> could share on a low Inverted Vee do compared to low flat-top dipoles. I
> relaize I could shunt feed this tower but that would require radials and 
> it's
> more work than I'd like to invest into a portable antenna.
>
> Thanks & 73!
>
> Dick- K9OM/9
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>
>
>
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