Rick,
I looked at your 40 mtr Low-Space vertical. In the box with all the
dimensions you have a "T" designator which does not appear on the drawing (I
couldn't find it) . Is this the top of the vertical above ground level?
73, Tony VE3DWI.
----- Original Message -----
From: "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Wednesday, August 20, 2014 8:32 AM
Subject: Re: [TenTec] 160 Meter Problem
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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