HF verticals

Anyone else out there using a multiband HF vertical, i currrently have a Sigma SE HF360 vertical which covers 10-80mtrs @1:1 but won't SWR on 11mtr

Hi Wade,

I couldn't find out a whole lot about this antenna apart from the typical sales literatures.
From the basics I could find it's a 17ft element with a 6:1 balun and seems to resonate as a quarter wave on 20m judging by it's impedance range. It does to me seem like the typical 'compromise' antenna as in, sort of does almost everything but not very well.
The literature does state the use of an external ATU or matcher so I would presume that it's SWR range goes beyond 1:3 which a lot of rigs with inbuilt ATUs, (such as your FT450d), won't manage.

Taking from that, it's too short as a half wave for 11m and may be part of your problem with a high SWR at that point.

I hate it when an antenna is advertised as being from 'x'MHz to 'y'MHz when they really mean 'sort of in some of that range' with terrible points on non-resonance. But that said, it is advertised as a Ham antenna rather than a CB antenna.

Sorry that's not too happy an analysis for you but the best I could figure.


All the best,
Victor

Usually with these multiband antennas using a specific length of wire/metal tube and ratio of Unun/Balun it's because it'll give usable SWR dips in the amateur bands but outside of those it'll be horrendous. Whilst it would be possible with a decent enough tuner to force it to work on 11m you'd cook the toroid in the UNUN that is the matching circuit this antenna uses.

your replies make perfect sense, thanks.

i am still working on a resolution to my dilemma, will update this page.

Screwdriver antenna such as a Tarheel using a 9ft whip. That'll tune everything from 160/80m to 10m.

Or...

SGC230/CG3000 tuner, gut the matching section out of your HF360 and connect the "hot" side of the SGC to the antenna bit of the HF360 and the ground lug to the pole it's mounted on. That'll tune everything continuously from 160m to 6m with no gaps and it'll be probably more efficient than the HF360 as it is.

The SGC230 manual has many examples of wire antennas you can use with it. It needs power but you can use Bias T's at each end of the coax going to it to feed 12V DC up the coax.

Bloody hell. 
.
There ain't half some clever geezers.

I am going to look into the SGC230.

The CT Forum just keeps on giving.

Thank you.

I've got the Moonraker GPA 80F which is oh so similar. I use it on HF and on 11m and my Alinco DX77 and MFJ 939 Auto tuner handles it with ease on AM, FM & SSB and gets the SWR down to 1.5 or lower across all bands from160m to 10m. Get yourself a Matcher (also known as a Tuner) such as an MFJ and all will be well.

Good luck