On 12/15/2012 7:59 AM, DAVID CUTHBERT wrote:
Mike that QTH looks alot like the Great Salt Lake of Utah where I have
operated a few 160 meter 'tests running a balloon vertical.
Dave WX7G
I learned about this QTH from Earl K6SE (SK). The terrain to the north
isn't so great (high
Mike that QTH looks alot like the Great Salt Lake of Utah where I have
operated a few 160 meter 'tests running a balloon vertical.
Dave WX7G
On Fri, Dec 14, 2012 at 9:52 AM, Michael Tope w...@dellroy.com wrote:
On 12/13/2012 3:14 PM, Tom W8JI wrote:
Somehow they thought moving the
[mailto:topband-boun...@contesting.com] On Behalf Of DAVID
CUTHBERT
Sent: Saturday, December 15, 2012 10:59 AM
To: Michael Tope
Cc: topband@contesting.com
Subject: Re: Topband: Fw: GAP VERTICAL QUESTION
Mike that QTH looks alot like the Great Salt Lake of Utah where I have
operated a few 160 meter
On 12/13/2012 3:14 PM, Tom W8JI wrote:
Somehow they thought moving the feedpoint eliminated the need for
radials with an electrically short antenna, when the real mechanism
was a 1/2 wave vertical was converted to a 1/4 wave groundplane 1/4
wave above ground and it only got a tiny bit
This is ~true only for a far field analysis (as defined by NEC software)
for a vertical monopole -- which includes the propagation losses present
in
the radiated fields from that monopole, over an infinite, FLAT, real-earth
ground plane.
However that is not reality.
I think what is going
I have already spoken extensively that your assertion is not proved, NOR is
the counter-assertion proved. I have no intentions of adding to that. I
am not persuaded either way, though BOTH sides of that question have
attractive points. I am waiting for something new to emerge, like
helicopter
So here's a question. I have a vertical mounted on a cliff side that performs
incredibly. My amateur's approach to figuring out why is that I modeled it in
EZNEC as being elevated 400 feet. That shows it performing nearly as well as if
it were on a tiny island in the great ocean.
Is it correct
So here's a question. I have a vertical mounted on a cliff side that
performs incredibly. My amateur's approach to figuring out why is that I
modeled it in EZNEC as being elevated 400 feet. That shows it performing
nearly as well as if it were on a tiny island in the great ocean.
Is it
Short version:
*** WARNING: Most locations do not have the fortunate circumstances to
support sparse or miscellaneous radial systems without exaggerated loss,
and the builder with constrained circumstances should attempt counterpoise
solutions designed specifically for those circumstances.
My first antenna, still in use, on moving to CO is a GAP Titan,
advertised to load up 80 thru 10 including WARC bands. The Titan is a
bit shorter than Voyager, 28 feet or something like it. The advertising
is correct, it loads up 180 thru 10.
But wait. Is it effective on all those bands? No.
This wonderful article written by L.B.Cebic W4RNL sure can make you a believer
in a simple wire inverted L. It is the last antenna discussed.
http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf
A $3 wire pulled up into a tree will beat just about any commercial antenna…
because
With the following caveat: The very sparse and short buried radial systems
he is showing are FAR more lossy in practice than shown in his gain tables.
Four twenty foot buried radials beneath a 1/4 wave L on 160, could place
you down 20 dB. You really can't do that as your 160 meter counter
The question is not How would you set up a contest station?… it is What is
practical to keep on air in a Senior Living situation?
Now if you have a bunch of grand kids you can talk into installing radials all
the better. Or if you have a fence along which you could install an elevated
20 dB implies that the ground system loss is 10X the inverted-L radiation
resistance.
This would result in an input resistance of 250 ohms and a minimum VSWR if
5:1.
I don't think that is what the real deal will deliver, do you?
Dave WX7G
On Dec 12, 2012 12:54 PM, Guy Olinger K2AV
Correction, 100X the loss.
The deal difference between a single ground rod and a BC station ground
will be about 6 dB.
Dave WX7G
On Dec 12, 2012 1:13 PM, DAVID CUTHBERT telegraph...@gmail.com wrote:
20 dB implies that the ground system loss is 10X the inverted-L radiation
resistance.
This
FWIW, at one point on a 5 acre remote parcel I had a GAP Voyager, GAP Titan,
80/160 parallel Inv-L over 120/125' radials, a 160M Inv-V, a F-12 C-4SXL beam
at 54', and homemade vertical fan dipoles for 10-40M. Tall 70-85' trees that
later burned in a forest fire held up the wires.
The GAPS
With the following caveat: The very sparse and short buried radial systems
he is showing are FAR more lossy in practice than shown in his gain tables.
Four twenty foot buried radials beneath a 1/4 wave L on 160, could place
you down 20 dB.
1% efficiency, and 99% of power dissipated in the
Not all loss is visible as series resistance in the counterpoise system,
which is the tack you are taking. Note that a dummy load is 50 ohms, and
does not radiate worth a hoot.
It takes modeling to identify some situations. One of my favorites in NEC4
results in a max gain of -18 dBi or so.
Guy, you make it sound like magic.
See the IEEE paper RADIATION EFFICIENCY AND INPUT IMPEDANCE OF MONOPOLE
ELEMENTS WITH RADIAL-WIRE GROUND PLANES IN PROXIMITY TO EARTH
Dave WX7G
On Dec 12, 2012 3:13 PM, Guy Olinger K2AV olin...@bellsouth.net wrote:
Not all loss is visible as series resistance
Lee
Cc: k...@arrl.net; topband@contesting.com
Subject: Re: Topband: Fw: GAP VERTICAL QUESTION
With the following caveat: The very sparse and short buried radial systems
he is showing are FAR more lossy in practice than shown in his gain tables.
Four twenty foot buried radials beneath a 1/4 wave L
] On Behalf Of Gary and
Kathleen Pearse
Sent: Wednesday, December 12, 2012 3:44 PM
To: topband List
Subject: Re: Topband: Fw: GAP VERTICAL QUESTION
FWIW, at one point on a 5 acre remote parcel I had a GAP Voyager, GAP Titan,
80/160 parallel Inv-L over 120/125' radials, a 160M Inv-V, a F-12 C-4SXL
beam
[I may have sent an incomplete version of something on this topic.
Apologies]
6 dB would be someone's calculation based on currents. The sometimes
abysmal performance of a ground rod based vertical system cannot be
explained by 6 dB. Cutting my amp from 1500w to 375watts just doesn't get
bad
On 2012-12-12, at 6:28 PM, Scott MacKenzie wrote:
Personally, I use an 80 M loop - I like it especially for stateside contest
like Sweep or FD. Nice solid signal on 40M and 80M.
By far, the absolute BEST DX antenna that I've ever had the pleasure of using
for the low bands is the
Guy,
here is where I believe your mysterious extra loss in NEC is coming from.
You are reading the average gain loss. NEC calculates that by integrating
the power at infinity and dividing by the power into the antenna. This
accounts for the far-far field ground losses that vertically polarized
Interspersed.
On Wed, Dec 12, 2012 at 7:10 PM, DAVID CUTHBERT telegraph...@gmail.comwrote:
Guy,
here is where I believe your mysterious extra loss in NEC is coming
from. You are reading the average gain loss. NEC calculates that by
integrating the power at infinity and dividing by the power
The GAP Voyager is not much better than a dummy load on 160m. On 80m and
40m it received fairly well compared to my other 80 and 40 antennas.
Doug
Original Message-
With the prospect of downsizing and moving into senior housing in the future
I am starting to look at vertical antennas
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