Refference Petlowany Coils:
Jim (A), I thought you said you were a "retired" lawyer.
With that contraption in back yards, you'll have XYL's lined up for miles,
wanting you to help them file for a divorce.
Or was that the idea behind this suggestion? ;-)
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim Allen
Sent: Tuesday, August 19, 2014 11:11 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] 160 Meter Problem
If you have a problem putting out radials for your vertical, why not try
Petlowany coils?
I have a home brew clone S9v31 with which I use 4 Petlowany coils. See the
photo at
http://forums.qrz.com/showthread.php?444568-Petlowany-or-Petlowaney-Coils-as
-Ground-Radial-Replacements&highlight=Petlowany+coils
73 de W6OGC Jim Allen
On Tue, Aug 19, 2014 at 3:51 PM, Rick - DJ0IP / NJ0IP <Rick@dj0ip.de> wrote:
> Hi Jim,
>
> It was nearly midnight last night when I read the entire presentation.
> I sure wish I could have heard the audio that accompanied it.
>
> Yes indeed, I overlooked the "vertical rules on 160m". Missed that point.
> That's it in a nutshell! That pretty much nails it!
>
> Total waste of time to even fool with horizontal antennas on 160m
> unless you just want to rag chew with the local yuks. It took me many
> years to arrive at this conclusion. What a difference it made to my
> contest scores once I switched to verticals!
>
> I haven't gotten any further yet with your material.
> My XYL had surgery today and I spent the entire day in the clinic.
> As I wrote earlier, there is so much meat in your paper, it will take
> a couple of days to go through all of this.
> While hanging out in the clinic today, I wished I had had the time to
> print your stuff out and take it with me, but it was just too late last
night.
> The reading material in the waiting room wasn't exactly my flavor.
>
> Also, as a result of reading your paper, it reminded me that I hadn't
> uploaded my own folded radial vertical to my web yet, so I did that
> this evening, including the EZNEC model of the antenna. It is a
> simple, effective 40 DX antenna requiring very little floor space.
>
> Mine had only one bend in the radial (copied from a Moxon design in
> RadCom).
> From your link to K2VA I saw it still works good with multiple bends
> which make 80 and 160m more feasible.
> Tnx for the tip. Hadn't ever heard of that before. I have lots of
> reading to do!
>
> Here's a link to my vertical with the single folded radial:
> http://www.dj0ip.de/vertical-antennas/40m-low-space/
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim
> Brown
> Sent: Tuesday, August 19, 2014 7:14 PM
> To: tentec@contesting.com
> Subject: Re: [TenTec] 160 Meter Problem
>
> On Mon,8/18/2014 10:16 PM, Rick - DJ0IP / NJ0IP wrote:
> > Jim, I didn't understand the point on slides 4 and 5.
> > I concur with everything you wrote.
> > Perhaps you mean where you wrote 130 ft. height for a horizontal
> > antenna is "low" on 160m.
>
> Well, remember that these slides accompany my talk, and also this talk
> was to the Pacificon Antenna Forum, which draws folks a somewhat above
> average knowledge of antennas. Ya hadda be there. :)
>
> The fundamental principle at work is that a horizontal antenna that is
> low as a fraction of a wavelength is an inefficient antenna, both
> because of ground losses and because all the energy goes more or less
straight up.
> I'd
> call any horizontal antenna lower than a quarter wavelength low. Most
> of us are stuck with low antennas for 40M and below.
>
> But what is is about the line "Verticals RULE on 160M" that you don't
> understand? To me, that says don't even consider a horizontal antenna.
> Further, the fact that the rest of the talk covers only vertical
> antennas (with various forms of counterpoise) should tell you
> SOMETHING. :)
>
> > Well my main point is, we have good dB numbers shown for different
> > vertical solutions, but there are no dB numbers shown comparing a
> > low dipole at a typical height one would have in a city - say 50 ft.
> > max, to anything vertical.
>
> You're right -- I almost never see that sort of comparison, which is
> what I did in the other link I gave. It compares vertical and
> horizontal antennas at various heights on 80, 40, and 20. The 80M
> plots are easily scaled for 160M. Simply double the heights shown on the
horizontal axis.
> So a resonant horizontal dipole at 80ft on 160 would behave like a
> resonant 80M dipole at 40 ft on 80M.
>
> Also, both of those presentations are 1 hour talks, and especially
> with the 160M talk, I had to have my roller skates on to get through
> it in that time.
> :)
>
> > There the difference is larger (in dB) than the difference between a
> > good vertical and a great vertical.
>
> Yes. And the primary difference between a mediocre vertical and a
> great one is the counterpoise/radial system.
>
> Another tutorial you might find interesting is this one.
> http://k9yc.com/VerticalHeight.pdf It doesn't address 160M, but it
> clearly shows the effects of the quality of the soil on a vertical
> antenna, and also the value of mounting vertical antennas higher.
>
> 73, Jim K9YC
>
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