You're absolutely right Frank, that antenna ("Open sleeve folded dipole") is
an excellent and little known/used wide-band antenna.
I find it much better than a Bazooka or that other thing which inserts a lot
of capacitors (forgot the name).
Anyone wishing more info on that antenna can find it on page 1-23 of the
latest "ARRL Wire Antenna Classics", or pull it up from the QST archives
(April 1989). The author of that article was Rudy Severns, N6LF.
It's also very easy to build a 4-wire cage antenna (spreaders available here
locally for that), but talk about a conspicuous antenna! I would prefer the
4-wire cage to the sleeve antenna, but it's a bit more difficult to build.
I THINK WE ARE ALL ON DIFFERENT PAGES ON THIS TOPIC.
Part of the problem is we all have our own set of requirements.
There's not going to be one solution that's right for everybody.
In Europe FOR SURE and probably in the states too, most people don't have
the luxury of being able to have multiple antennas. I have had QTH's in the
states and here in Germany where I could and I took advantage of it at the
time, but life moves on and QTH's change. So do my interests in ham radio.
The beauty of the built-in ATU is the ability to match a compromise antenna
to the transceiver (and as Geoff pointed out, protect the finals).
I don't think anyone here disputes the fact that it's better to have
well-designed antennas and if necessary, matched at the antenna. It's just
not practical in many, perhaps most cases. If you are able to do it, I'm
envious, but happy for you. One day I hope to be able to do that again too.
WE ARE OFF TOPIC FROM THE ORIGINAL SUBJECT OF THIS THREAD.
I want to go back and answer some of John's questions, but I will do it in a
separate email.
73
Rick, DJ0IP
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Frank
Sent: Wednesday, November 30, 2011 4:59 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Jupiter Autotuner upgrade?
Rick - DJ0IP / NJ0IP wrote:
>Frank,
>
>Had a good laugh at your last sentence.
>
>Now take any antenna resonating on 80m.
>What's your SWR at 3.500 MHz? 3.800 MHz? 4.000 MHz?
>
>I don't know a reasonable antenna that is under 2:1 across this range.
>In fact most will rise to 4:1 or higher.
>
>
I had my blinders on thinking about 20 meters and up. 80 meters is a
problem but there is a solution for those who need to cover the entire
band. Folded dipole cut for the lower middle of the band and a closely
spaced parasitic wire cut for the higher end of the band. I used such
an antenna a few years back and was able to cover both the high end of
75 and 80 CW with less than 1.5:1 SWR. Of course a folded dipole
sporting a parasitic wire is not exactly inconspicuous.
>Also, I have a peculiar situation of having lots of space, about 2 acres,
>but am renting and the owner lives in the other half of the house. We
>negotiated permission for ONE ANTENNA before I signed the lease. He
>wanted it as far out of site and inconspicuous as possible.
>
Again, appologies for my blinders. Being beholding to an unsympathetic
landlord is the pits.
>
>
>With one antenna and wanting to work all bands, I would normally use
>openwire to feed an 80m dipole.
>Openwire is out of the question because it is highly conspicuous.
>
>I put up a special OCF Dipole (just one radiator, not multiple) which
covers
>80, 40, 30, 20, 15, 12, and 10m. 7 bands with just one antenna, fed with
>about 100' of LMR-240. The SWR is fairly good on all bands, being as high
>as 3.5:1 (worst case) on one band and averaging 2:1 on most bands. Not
>exactly the perfect antenna, but it gets the job done on all of these
bands.
>
>I don't know of any other antenna fed with coax that can give an acceptable
>match on all of these bands.
>THEREFORE, I am quite happy to use the built-in ATU in my Eagle (or
Jupiter,
>or Orion, etc.), even though in a perfect world, this would not be my
>antenna of choice and I would not want to have to use a tuner.
>
>I'm taking about reality, not virtual reality! :-)
>
>
Your reality is a little different from mine. I have lots of antennas,
no landloerd, and understanding neighbors. I did live in an appartment
many decades ago. At that time my hamming was done as a mobile.
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