I could give other advice but the best that I could offer is to check out
Rudy's, N6LF, site: https://www.antennasbyn6lf.com/ Regrettably, this isn't all
that he's published so further searching might be in order. QEX published a
series in 2009-2010 of his stuff.
In my "Antennas" document
er K2AV
Sent: Sunday, December 30, 2018 11:32 PM
To: chet moore
Cc: TopBand List
Subject: Re: Topband: Inverted L improvement question - Part 2
Hi Chet,
Before we start, a disclaimer: I still have my MP, maybe I'm a radio
hoarder. I do have a 75A3 and a Johnson Ranger and Courier and an FT 101Z
Thanks again everyone. I've read all your suggestions and advise and
although I won't be able to make some of the more difficult (or impossible
at my site) changes there are a few things I'm willing to try.
I read the w0btu.com webpage and I'm not really that far off from that
setup. Minus that
VP2A, ZD8W, VQ9Xx, KL7AIZ, KG4ZO, N6Zo/HH9
N6ZO/6Y5
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Rob
Atkinson
Sent: Sunday, December 30, 2018 9:52 AM
To: topband@contesting.com
Subject: Re: Topband: Inverted L improvement question - Part 2
Hmmm.
hen I asked what else I could do he suggested that I might want
> to consider putting up a FOR SALE sign.
>
> Thanks again for sharing your results.
>
> 73
>
>
> Chet N4FX KP4EAJ, VP2A, ZD8W, VQ9Xx, KL7AIZ, KG4ZO, N6Zo/HH9
> N6ZO/6Y5
>
>
>
>
>
>
KG4ZO, N6Zo/HH9
N6ZO/6Y5
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Rob
Atkinson
Sent: Sunday, December 30, 2018 9:52 AM
To: topband@contesting.com
Subject: Re: Topband: Inverted L improvement question - Part 2
Hmmmyou DID relocate or rebui
Todd
If you are interested in experimenting, you could try a K2AV folded
counterpoise under that inverted L. If installed as recommended, it will
provide a decent counterpoise system. One advantage to the FCP is that it
is possible to also end fed the system, should that be a requirement.
I
Hi Rob,
You ask some good questions and make some interesting observations.
Nope, it is the same radial system. I don't have a reasonable way
(time/money/effort) to create a whole new 50-60 wire buried radial system
for this experiment. I just disconnected the 43' vertical from the radial
Hmmmyou DID relocate or rebuild your ground system so it converges
on a point below the bottom of the 100 foot tall wire right? I mean,
you aren't using the 43 foot vert. ground system with the 100' wire?
A series fed vertical isn't rocket science so let's not over think
this. If it doesn't
Goins , TopBand List
Subject: Re: Topband: Inverted L improvement question - Part 2
Message-ID:
Content-Type: text/plain; charset=utf-8; format=flowed
Problem #1. The swr indicates about a 140Khz plus < 2:1 bandwidth (2 *
1880-1810) which implies a high radial resistance. Are the eleva
Exactly! You have a lot of loss in your ground (or something), Todd.
Perhaps it's the lack of a proper feedline choke.
73, Mike
www.w0btu.com
On Sat, Dec 29, 2018, 11:00 AM Grant Saviers wrote:
> Problem #1. The swr indicates about a 140Khz plus < 2:1 bandwidth (2 *
> 1880-1810) which implies
On Sat, Dec 29, 2018 at 8:59 AM Grant Saviers wrote:
> Problem #1. The swr indicates about a 140Khz plus < 2:1 bandwidth (2 *
> 1880-1810) which implies a high radial resistance. Are the elevated
> radials fully insulated from trees, not contacting foliage, etc? Add
> three more.
> Problem #2.
Problem #1. The swr indicates about a 140Khz plus < 2:1 bandwidth (2 *
1880-1810) which implies a high radial resistance. Are the elevated
radials fully insulated from trees, not contacting foliage, etc? Add
three more.
Problem #2. Your coiled coax choke may be making things worse. Check
Those SWR readings seem to indicate a very large bandwidth, to the extent
it might suggest that your ground resistance losses are swamping the
antenna R radiation resistance. It would be nice to know the R value at
resonance, where there is no J value. Too bad the analyzer is overloading.
A
A person emailed me to ask if I could take SWR readings at the rig without
a tuner. Since my antenna analyzer is non-op due to the AM station nearby.
The feedline is about 140' of LMR-240.
Here is the indicated SWR at the 7300:
1.810 1.2:1
1.830 1.3:1
1.850 1.5:1
1.870 1.8:1
1.900 2.3:1
1.940
Hi Mike,
Oh, I would totally believe that the air-wound choke is ineffective at
160m. It just happens to be what I had available to use when I rigged up
the elevated radials in the cold rain yesterday. I figured I'd put it in
line just in case.
Thanks for the choke links, I will read the info on
Hi Todd,
I'll bet the farm (if I had one) that your air-core choke is ineffective.
Take at look at
http://www.karinya.net/g3txq/chokes to see what I mean.
A very, very good common mode choke is the one I have on mine, from
http://audiosystemsgroup.com/RFI-Ham.pdf. There is no better material
Sorry, I wasn't completely clear in my post. The elevated radials are not
connected to the buried radial field. They are two separate entities. Now
the elevated radials do sit above or cross some the buried radials in some
places so I'm sure they do interact but they aren't directly connected
Hello Grant,
Your advice is spot-on! Elevated radials MUST NOT be connected to ground.
Perhaps that's one of the reasons why Todd's inverted-L is working so
poorly.
Another important thing is to have a GOOD choke balun right at the
feedpoint. *We need to keep the current off of the feedline
Modeling I've done shows it a bad idea to have in ground and elevated
radials connected together, but that is not clear from what you
described. Then with the elevated separate, moving the feedpoint up at
least 8', to 12' is better and elevated radials run out at that height.
I think it is a
Two 100 x 3 ft rolls of chicken wire were added this fall. I have about 45
radials, good conductivity, clear view, and the sump pump dumps out nearby. It
is quiet in the country but the beverages are better. I am putting up a
SAL30. It will be better for USA contests. The F/B is good enough
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