Topband: First 160m Contest

[Mike Waters W0BTU]

Thanks for the info! There's one thing I forgot to ask: Where the coax shield connects to the elevated radials, is that point also connected to a ground rod? Mine is, and ON4UN's book seems to imply that it shouldn't be.

I also have an RF choke at the feedpoint, about 50' of RG-6 coax coiled up in an 18" diameter coil.

I'm tuning the inverted-U with a series capacitor at 1830.

I appreciate your time. Thanks again.

73,
Mike Waters
W0BTU


--- On Thu, 2/4/10, James Rogers <jdrog at bellsouth.net> wrote:

> From: James Rogers <jdrog at bellsouth.net>
> Subject: Re: Topband: First 160m Contest
> To: "Mike Waters W0BTU" <mrscience65704 at yahoo.com>
> Date: Thursday, February 4, 2010, 12:36 PM
> Mike,
> 
> I figured my radials where too long at 130 feet, so I just
> started  
> cutting them back 5 ft at a time and then doing an swr plot
> from 1800  
> to 1950. I have one radial that runs 180 deg south and the
> other one  
> runs 0 deg north for about 35 feet then turns 90 deg west
> for the  
> final 85 feet. So, no fancy analysis tools, just the swr
> meter and a  
> simply x-y plot.
> 
> Jim
> 
> 
> On Feb 4, 2010, at 12:44 AM, Mike Waters W0BTU wrote:
> 
> Hello Jim,
> 
> Thanks very much.
> 
> Something seems wrong with this inverted U here. Mine is
> over a 60'  
> tall oak tree. Two elevated radials 10' (or less) high.
> 
> How'd you prune your radials for resonance? I was going to
> measure the  
> current in them (to see if they were about equal), but
> there was not  
> time before the contest.
> 
> My radials are in line, but 90 degrees to the antenna as
> viewed from  
> above.
> 
> Maybe I'll keep it up a little longer and give it a fair
> try.
> 
> Most people have trouble hearing my 100 watts. I did manage
> to work  
> CN2R a couple of nights ago, but he was s6 without the
> preamp. He had  
> trouble hearing me.
> 
> 73,
> Mike Waters
> W0BTU
> 
> 
> --- On Tue, 2/2/10, James Rogers <jdrog at bellsouth.net>
> wrote:
> 
> > From: James Rogers <jdrog at bellsouth.net>
> > Subject: Re: Topband: First 160m Contest
> > To: "Mike Waters W0BTU" <mrscience65704 at yahoo.com>
> > Date: Tuesday, February 2, 2010, 8:46 AM
> > Mike,
> >
> > Check out my note to Brian,
> >
> > Brian,
> >
> > I put up an inverted U for the 160M and it is the best
> 160M
> > antenna I have ever had, I live on a 100x200 lot.
> >
> > I used an EZ Hang to shoot a weight over the top of a
> 70 ft
> > pecan tree. I then pulled up 130 feet of #12 THHN wire
> from
> > Home Depot (500 foot roll is $50) and draped it over
> the
> > tree.
> >
> > I then hooked up two 130 foot elevated radials 6-7
> feet off
> > the ground. I then trimmed the radials back to about
> 120 ft
> > each to achieve resonance. My swr is 1.5 at 1800 to
> 1.5 at
> > 1960m with 1:1 at about 1840 or so.
> >
> > I worked 44 states and provinces and 11 countries
> with
> > 100W.
> >
> > Give it a try if you have a tall tree.
> >
> > JIm N4DU
> >
> >
> >
> >
> >
> >
> >
> > On Feb 1, 2010, at 10:57 PM, Mike Waters W0BTU wrote:
> >
> >> From: kd6nrp at earthlink.net
> > <kd6nrp at earthlink.net>
> >> Subject: Topband: First 160m Contest
> >> To: topband at contesting.com
> >> Date: Monday, February 1, 2010, 11:48 AM
> >
> >> Last weekend's 160-meter content was the first
> > 160-meter
> >> event I have ever participated in.
> > [snip]
> >> Time to start thinking about a better antenna. A
> few
> > people
> >> have reported success on 160m with an "inverted
> U". I
> > wonder
> >> how well such an antenna would work on other 160m
> and
> > other
> >> bands.
> >>
> >> 73
> >>
> >> Brian Webb, KD6NRP
> >> Ventura County, California
> >
> >
> > Me too.
> >
> >
> > I tried an inverted-U based on these web sites...
> >
> > http://lists.contesting.com/_topband/2006-12/msg00161.html
> > http://users.erols.com/k3mt/inv_u/u_160.htm
> >
> > ... and mine doesn't work. Perod. :-(
> >
> > Mine was based on K3LR's link (the first one) with the
> two
> > elevated radials. My radials were 132' long and 10'+
> high,
> > but the antenna was 150' long. Used a series variable
> cap to
> > match it @ 1830 MHz.
> >
> > It's the worst antenna I have ever tried. But I'm
> convinced
> > that I did something wrong, since Tim, K3LR, is a
> very
> > knowledgeable guy!
> >
> > I would be VERY interested to hear from others who
> have
> > tried this antenna, before I take it down and try
> something
> > different.
> >
> > 73,
> > Mike Waters
> > W0BTU
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > UR RST IS ... ... ..9 QSB QSB - hw? BK
> >
> >
> 
> 
> 
> 
>