Hi guys,
I also use a half sloper for 80 and the feed point of the 1/4 wave length
wire is only about 8 ft above the ground, fed directly with 50 ohm coax.
Works great on dx but not so good for local contacts. Simple and effective
antenna. Only using a ground rod but a few radials would definitely help.
73 Bert, VE3OBU
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Tom Haavisto
Sent: Wednesday, September 15, 2010 12:39 PM
To: Al Williams
Cc: Tower Talk; RLVZ@aol.com
Subject: Re: [TowerTalk] 80-m. Inverted Vee vs. Dipole Performance
Take a 1/4 wave length of wire (half an inverted vee), and connect the hot
side of the coax to this. Shield from the coax is attached to the tower.
Signal is vertically polarized, and may show a small null off the back of
the antenna. You may have to adjust the angle of the sloping wire for best
SWR.
Tom - VE3CX
On Wed, Sep 15, 2010 at 12:07 PM, Al Williams <alwilliams@olywa.net> wrote:
> what is a half sloper? is it a half inverted vee (which is a sloper)?
>
> k7puc
>
>
> ----- Original Message ----- From: "Tom Haavisto" <kamham69@gmail.com>
> To: <RLVZ@aol.com>
> Cc: "Tower Talk" <towertalk@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@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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