Ignacy,
There are 2 things that come to mind with your array elements as you
describe them.
The very first thing is when this has happened before it has been the result
of not sufficient earth grounding from a ground rod mechanism at each element.
This can result from insufficient ground rod size/length or the ground
condition itself. Dry and or rocky soil is insufficient to cause a low
impedance signal source to the Hi-Z amps and under extreme cases will cause a
low frequency loss of performance. If this is the condition it can be remedied
by installing 6 to 8 ground radials at each antenna element that are roughly
the same length as the radiator itself. Space radials the same for all elements
The second thing is your element description sounds as if you have used very
small wire as the element itself at 18 feet length. These shortened elements
exhibit a very small capacitance as the output impedance of the element itself.
Larger diameters have a greater output capacitance which increases signal and
also decreases the chance for differences between the elements.
Personally I would add 2 or 3 more wires the length of each element to
increase its apparent diameter. Then make sure there was a good earth ground
under each element with and/or without adding radials.
It also may be of help if you sent some element mounting and grounding
pictures direct to me for comment.
Lee K7TJR OR
-----Original Message-----
From: Topband <topband-bounces+k7tjr=msn.com@contesting.com> On Behalf Of
Ignacy Misztal
Sent: Tuesday, September 19, 2023 12:48 PM
To: topband@contesting.com
Subject: Topband: HiZ 4-8 and beverages
I have 600 ft reversible BevFlex beverages and recently I bought a used HiZ 4-8.
Both are about 300ft away from a shunt-fed tower for 160m and 4 sq for 80m.
On 80m, HiZ has a better F/B and hears slightly clearer than the beverages.
On 160m Hi-Z is deaf, with S/N at least 6 db below the beverages. A marginal
copy on the Hi-Z is a clear copy on the beverages, and a marginal signal on the
beverages is no copy on Hi-Z 4-8. Does not matter what direction. No big
buildings around although some large trees.
My verticals are wires attached to 18ft telescopic fiberglass poles.
The noise level from Hi-Z is decent so the preamps must be working. All
directions show the same background noise so probably the individual HiZ Plus
amps are OK. The whole array had lightning damage before and was repaired by an
associate of Lee.
I have a triangular Hi array at another QTH, very close to TX antennas and
large trees. It has old ANT amps (not plus). Its sensitivity was never a
problem.
Does anybody have an idea what could cause HiZ to be poor on 160 while being
good on 80m?
According to reviews, HiZ should be pretty good on 160m.
Ignacy NO9E
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