Mike etal,
I am using such an antenna. I significantly modified 4 MFJ-1792's to
work on 80 meters. I first used 16 but later upgraded to 32 1/4 WL
radials on each antenna and a Comtek combiner. The footprint is full
sized. Although it's narrow band (less than 100 KHz) it seems to do
well both on transmit and receive and hold its own on the low end of 80 meters.
From my modeling, I lost less than 1 dB due to the losses in the
inductor. I replaced the MFJ top hat coat hanger wires with 8 49"
stainless steel whips, the kind usually used as 5/8 WL 32 meter car
mounted whips. This allowed me to significantly decrease the inductor
size from about 185 turns to 70 tuns and significantly lower the losses.
This season I worked many rare ones while only running 4 Watts at the
transmitter so it does work. My only problem is that an ice storm in
December caused large pine trees to fall on the guy wires and break
several of the verticals. However, I was able to repair and replace
the damaged tubing and all was back to normal just as the deep snow came.
73,
Joe, W1JR
At 11:30 PM 3/11/2009, W0MU Mike Fatchett wrote:
>Sorry,
>
>Brain was out thinking the typing fingers LOL! I forgot the subject which
>would have helped too.
>
>Yes we are on the same page. Bandwidth is worth considering.
>
>
>
>
>"A slip of the foot you may soon recover, but a slip of the tongue you may
>never get over." Ben Franklin
>-----Original Message-----
>From: Billy Cox [mailto:aa4nu@ix.netcom.com]
>Sent: Wednesday, March 11, 2009 9:23 PM
>To: W0MU Mike Fatchett
>Subject: Re: [TowerTalk] (no subject)
>
>Hey Mike ... are you asking as to a shortened array vs full sized?
>
><me thinks there is a word missing in your question>
>
>Short answer is ... they will work, AS LONG AS you have a better than
>average ground system ... that was my finding when I pondered this very
>question before I took my full sized array down for R&R.
>
>The other point mentioned frequently was the bandwidth was better with the
>full size ... most ended up using some form of switching to go from CW to
>SSB. <Note this was before the SSB band changes>.
>
>So, are we discussing the same thing here?
>
>73/bc/NU
>
>-----Original Message-----
> >From: W0MU Mike Fatchett <w0mu@w0mu.com>
> >Sent: Mar 11, 2009 10:53 PM
> >To: 'Tower Talk' <towertalk@contesting.com>
> >Subject: [TowerTalk] (no subject)
> >
> >I have searched Google for quite a while now and have come up empty.
> >
> >Has anyone used/modeled/etc an 80m 4 sq over a full sized 4 sq. array?
> >
> >I have not really found any shortened 80 verticals. I am not sure that
> >a shortened solution is going save much expense.
> >
> >I see DX Eng has a 66 ft vertical that needs to be guyed and runs about
> >$200 for the aluminum kit, $160 for the tilt base and about $80 for the
> >guying kit.
> >
> >I would be curious to know what others might have used.
> >
> >I am looking at the bent 4 SQ by K9RS hung off my tower.
> >
> >I am looking to get a lower angle signal out on 80 for better Dx.
> >
> >I appreciate the feedback.
> >
> >Mike W0MU
> >
> >
> >_______________________________________________
> >
> >
> >
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