I had the same problem with my K9AY loop. Despite being
in a wooded area that seemed to have very damp soil the
earth conductivity was poorer than I had expected.
I added eight short radials under the loops and that made a
huge improvement. I also added some cheap CATV ground
rods to tie the ends
I had a similar issue with my K9AY loop. It was very non directive, even
with a short ground rod. I added four ground
radials laid under the loops to the apex points where they met
the ground anchors. That fixed the problem. I also added
four of those cheap TV ground rods at each corner and
If the problem is related to receiver overload, than a trap at the BCB's
operating frequency will correct the problem. Unless the problem is
related to a non-linear junction (rusty fence wire, etc.) generating local
IMD or harmonically related signals due to rectification.
If the problem is the
I think Tom, W8JI's main concern with the K2AV was the unbalanced nature of
the feedpoint, due to the short
electrical length of the FCP counterpoise system. His
observation was that lengthening the counterpoise to
make it resonant would reduce feedpoint voltages.
I think his points were that he
You do a search for radio amateurs by city and state. Here is the list for
Los Angeles, as an example:
http://www.city-data.com/aradio/lic-Los-Angeles-California3.html
If it is a smaller town, it should be easy to identify the ham involved
with that location.
Pete W1BR
_
4 to 8 ohms seems to be rather low for an inverted L... that seems to be
more in line for a short vertical? I measured closer to 26 ohms using my
analyzer at resonance. I'd expect some improvement in R losses, but I was
more curious about the elevation pattern for the system.
Pete
My K2AV counterpoise is 12 feet off ground, which leaves me with a vertical
run of about 45 feet for the vertical portion of the inverted L. I've
noticed that the walnut tree I am using for a support has branches that go
up another 25 feet or so... albeit there is a bit more sway in strong winds
I will second the need for short radials if your soil is very poor. I
installed my K9AY system last fall after it sat new and unused in my shed
for a few years.
The first I noticed that it had very poor rejection of distant signals of
the back of the loops. I added the suggested radials, and
I recall hearing FT8 activity on 1830 kHz last evening ... isn't a bit low
in the band for digital modes? I hope FT-8 activity doesn't squeeze all of
the CW activity down into the DX portion before the dust settles.
Pete k1zjh
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Indeed, that is what I meant to say.
On Tue, Jan 22, 2019 at 10:03 AM Bruce wrote:
> You maybe confusing "Radiation Resistance" with "Feed point Resistance".
> It often will lower "Feed point Resistance", but raise "radiation
> Resistance". 73 Br
I would think adding radials would lower the Radiation resistance. Also,
the SWR curve should narrow as ground losses are reduced; since the effect
of ground loss resistance swamping the results lessens.
At some point I suggest, as others, that you get on for the contest and see
what you can
Hello
You want the elevated radials as high as possible. 3 meters is probably as
low as you would want. 5 meters would probably be optimum.
To be effective, the radials would need to be resonant, and you would need
at least two, preferably four. The current on each radial should be equal.
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
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
This is a manly solution for launching antennas... just load a frozen carp
and you can cast your antenna line 300 yards! If the carp gets stuck in a
tree, the birds will take care if it.
https://www.facebook.com/InTheKnowInnovationAOL/videos/1912747892351198/?fref=gs=13909010799_location=group
I'd avoid the TV splitters, quality is all over the place and the lower
frequency limit varies. You would really want to measure the loss at 1.8
MHz before committing to use one.
I've been playing around with satellite TV splitters (most specifically
DirecTV splitters (
A drain resistor would be advisable if there is no DC return path to
earth... if there is no inductor or resistance between the antenna and
earth it can develop wind or snow induced static voltage buildup, which can
lead to discharges that will cause noise in the receiver. Static voltages
can also
Some of the cheap imports may be metric thread.
Regarding N or UHF, I've switched to good quality crimp fittings eons ago,
and if one buys the proper prep and a quality crimp tool they are very
reliable.
Pete k1zjh
_
Searchable Archives: http://www.contesting.com/_topband -
I made my own. There are tons of plans on the internet for spud launchers
or antenna launchers. The designs are basically the same. It costs around
60 bucks to make one, only because you will end up with extra material (PVC
tube) that will go along way to making one or two more. These are great
For comparison sake... my inverted L measure 19 ohms over a K2AV FCP.
Increasing the vertical wire height gained another several ohms... ended up
with an R value of 26 ohms at resonance (no reactive component.)
Pete
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Searchable Archives: http://www.contesting.com/_topband -
Regarding 10 kHz harmonics from BCB stations... last year I was using my
HQ-140 receiver for casual SW and ham monitoring at my computer desk. With
a full size 160 meter the Hammarlund overloaded to the point where I was
hearing an IMD beatnote at every 10 kHz spot on the band. Fortunately, I
Gary. if you are still reading this thread. I have a very early K9AY loop
and mast kit. I believe my relay box was the second version where you went
from DC/AC control to a three wire DC relay voltage system. The antenna
mast kit used galvanized timber spikes, if that helps date the system.
Was
Adding four cheap 3/8" 4-ft TV ground rods--one at each of the ends of
each of the 21 foot radials-- did the trick. The lone ground rod at the
hub was not enough. Now have good deep nulls in all 4 quadrants.. Adding
four more radials didn't seem to improve things as much as the first set of
Is there a schematic available online for the YCCC preamp? I see DX
Engineering is long sold out of kits and I'd like to try dead bugging a few
amplifiers to play with.
Pete
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Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Hello to the group. I installed a K9AY system last week and added four 21
foot radials on ground radials with a ground rod at the center. The
antenna didn't seem to have much directivity, so today I added another four
4-ft inexpensive TV type ground rods at the ends of each of the radials.
We've
Why would bonding the added matting be required if it is laid over or
beneath an existing radial field? It reduces ground losses regardless.
Peter
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Topband Reflector Archives - http://www.contesting.com/_topband
It would be interesting to see if a 75' x 4' run of galvanize poultry
fence laid on the ground
beneath an FCP affected the R ground losses, as seen on an antenna
analyzer. I read the
ground losses were estimated at 8%; whether 300 sq. ft. of ground screen
would do anything
might be a good
Has anyone with poor soil considered or tried adding a few
hundred square feet of cheap galvanized wire mesh on the ground beneath
the FCP to reduce ground losses? I suspect
improving the near field ground losses would help slightly,
but was curious if anyone actually tried it?
Pete
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