A Delta Loop is probably the least noisy of anything you can hang off an
AM tower. I tired both slopers and a Delta Loop here (corner fed) and
there and the noise was significantly lower on the Delta Loop for weak
signal reception. The Delta Loop here had a slight total slope to it to
try and minimize inter-coupling to a 300 foot insulated AM tower.
Herb, KV4FZ
On 6/10/2014 12:17 PM, Mike Furrey wrote:
I would hang a delta loop off of that tower very easy to tune and match with a
1/4 wave length 75 ohm coax. You don't have to worry about complex matching
systems or ground. BUT it is noisy on receive.
73, Mike WA5POK
On Tuesday, June 10, 2014 9:25 AM, DALE LONG <dale.long@prodigy.net> wrote:
Hi Dado:
I agree with you. Thanks to advice from AA1K, I built a sloping dipole at 200
feet for 80m in HH7-land. I was really loud into EU and USA with only a
borrowed TS-50.
We are still looking for operators for the HH2 160m dxpedition Dec1-Dec8.
73
Dale - N3BNA
P.S. I am forever sad about the time that I tried a sloping dipole on 160m
from HH7. It was the last day of my trip. We finished the antenna after dusk
and put it up. It was my chance to be loud on 160 and make many people happy
(I even had an argument that i should not do this because it was in a remote
area and we had to fly at 6:30 AM). So it was Friday night and I tuned around
1812 and there I heard SSB signals..then all the band was full of SSB signals.
W1 stations working W2 stations and W3 stations working W4 stations. I could
not break the pileups. I could not get any answers to my CQ calls. My one
night to be on 160 with good antenna was lost because of the SSB contest!
________________________________
From: Dragoslav Balaban <dado@prijedor.com>
To: 'Carl' <km1h@jeremy.mv.com>; Gary@ka1j.com; Topband@contesting.com
Sent: Tuesday, June 10, 2014 7:02 AM
Subject: Re: Topband: AM broadcast tower and 160m dxpedition
hi all,
As I can can see in EZNEC, simple model, Tower 2 Ft over average ground, 242
Ft high,
best and simplest solution is to put sloping Dipole, K8UR style, Arch shape,
>from top of the Tower,
Gain in dipole direction can be as much as 3.84 dBi at 17 degrees Vertical
angle,
one Dipole toward EU 60-90 degrees, and maybe other to west 270-300
degrees,
that would cover all 360 degrees , with F-S 90 degrees less then 3 dB
difference, but 90 degrees from HH north is NA, south SA, and thats
close-almost local, so should be no problem...
73 gl, looking forward HH , would be new one 160m hi
dado E74AW
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Carl
Sent: Wednesday, 26 February, 2014 01:44
To: Gary@ka1j.com; Topband@contesting.com
Subject: Re: Topband: AM broadcast tower and 160m dxpedition
Make them shorter and they will often do well over tidal marshes but not
over open water.
For a 240' tower Id suggest gamma feeding it up at the 1/4 wave point and
use 4 elevated radials. It the AM BCB radials are installed they will make
an excellent ground screen but do not connect them to the 160M feedline.
Carl
KM1H
----- Original Message -----
From: "Charlie Cunningham" <charlie-cunningham@nc.rr.com>
To: <Gary@ka1j.com>; <Topband@contesting.com>
Sent: Tuesday, March 25, 2014 5:24 PM
Subject: Re: Topband: AM broadcast tower and 160m dxpedition
That's not so surprising Gary !! te Way the Beverages and similar
slow-wave
antennas work is that they depend on the lossy GND underneath for their
operation, so a salt marsh would not be a very beneficial GND structure
under a Beverage!
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Gary
Smith
Sent: Tuesday, February 25, 2014 5:09 PM
To: Topband@contesting.com
Subject: Re: Topband: AM broadcast tower and 160m dxpedition
My Inv-L is on a salt marsh on Long Island Sound in Connecticut & I
ran two bidirectional 860' beverages over the salt marsh. I had
terrible results with the beverages, very noisy and hardly any
improvement over the Inv-L, much of the time the Inv-L was more
effective on Rx. With that, my experience of beverages & salt marshes
says to avoid this route.
I ended up with a HI-Z Triangular array for Rx and it works very well
at the same location.
Gary
KA1J
No, I don't believe 240' is too high - especially if the tower has a base
insulator! It would be so close to 1/2 wave on 160, that it could be fed
very well as a 1/2 wave radiator on 160, either via a parallel tuned tank
or
a 1/4 wave of perhaps 450 oh ladder line. A 1/2 wave radiator wis an
excellent transmit antenna, and, because of the high feed-point impedance
can be driven against a very modest ground arrangement
Like you, though, I believe they would do well to put up some terminated
loops, or perhaps a Beverage (or 3?) for receive antennas! A 240'
vertical
would, I think, be a VERY noisy receive antenna. If they put up a KAZ
terminated loop that only requires one overhead support, they could steer
it
around with ropes and weights on the ground. The KAZ is like ON4UN's
FO0AAA
160 receive loop.
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of
Richard
Karlquist
Sent: Tuesday, February 25, 2014 3:38 PM
To: topband@contesting.com
Subject: Re: Topband: AM broadcast tower and 160m dxpedition
Congratulations on your adventure.
In the past, I have seen some of these AM tower efforts
ruined by lousy receive conditions. I suggest you
get an advance team out to the site to check
out the noise level etc. and maybe put up some
temporary beverages, loops, whatever and LISTEN
on them. Use WWV and WWVH on 2.5 MHz as a beacon.
Others can comment on whether 240 feet is too high.
Rick N6RK
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
---
This email is free from viruses and malware because avast! Antivirus
protection is active.
http://www.avast.com/
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4335 / Virus Database: 3705/7124 - Release Date: 02/25/14
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|