Ron,
As you are considering a two band 4 square I want to draw your attention
to this:
If you prolong the mast lenght from 60 ft. To a 80m 3/8 wl. And combine
it with a top or linearloading to resonate 160m (better than the coil)
then you will be able to utilise your "relatively" short ground space
available in a better way from point of minimising ground losses on the
80 m section as increased (3/8) wl. Will heighten the current maximum.
All this ofcourse means your 160 m 4sq. Will have to be spaced 1/8 wl.
Which could be a draw back as it would need another matching phase angle
(135 degree) and it would probably be more sensistive to physical
variations due to closer coupling of the elements.
Albeit I am planning such a system myself.
Regards,
Henrik
OZ1ING
-----Oprindelig meddelelse-----
Fra: topband-bounces@contesting.com
[mailto:topband-bounces@contesting.com] P? vegne af Ron Feutz
Sendt: Wednesday, July 16, 2003 9:24 PM
Til: topband@contesting.com
Emne: Topband: New 4-square
Gentlemen,
I recently moved to a new QTH and plan to build a new 4-square.
My antenna field is 175' wide X 500' long, and is heavily wooded. An
asphalt driveway runs roughly down the middle of the antenna field. The
long lot lines run directly N/S. A traditional 1/4 wave per side 4-sq,
with the sides parallel to the lot lines, would be properly oriented NE,
SW, etc. There would be 2 elements on either side of the driveway with
short radials towards the sides and middle of the lot (E-W) and longer
ones
towards the ends (N-S). Because of the compromise radial system I would
want to connect the 4 elements' radial systems together.
Questions:
1. My ground system and phasing lines will have to cross the driveway.
I
can do one of the following: Run buss wires along both sides of the
driveway and connect the radials to the buss wires and then either go up
and over the driveway (about 8' or so) to connect the systems together
with
a relatively few wires, or bore under the driveway ( I don't know how
this
is done or how much it would cost) to connect the systems together.
Would
the up and over method cause any performance problems or pattern
disruptions? It would be easy, as there are plenty of trees available
for
supports (the driveway is only 8' wide).
2. For the phasing lines, the same considerations apply. I would
probably
have to use 3/4^ lines if I go up and over. Any considerations I should
know about? Would I need chokes on the lines if that small section were
to
be elevated?
3. I currently have the Comtek box and am satisfied with it. The Array
Solutions box claims a bit more gain, 6db more F/B and no dump power (I
got 5-10% dump with the Comtek on my old system at resonance). It
seems
to me that for TX'ing, the slight improvement isn't worth the high price
of
the A/S unit. The added 6 db F/B may be worth it, as the antenna will
also
be my primary RX antenna and if I truly will get the extra F/B I would
probably spend the $. Opinions?
4. I will also be building an 80M 4-sq. If I put it inside the 160
array
to take advantage of a common ground system, I don't think it will
affect
the pattern on 160. Would I have to detune the 160 array somehow to get
best performance on 80?
BTW, the 160 elements will be 60' masts with skirted guy wire top
loading
and a fat coil at the bottom to get resonance/matching.
Looking forward to the combined wisdom of the best reflector in ham
radio.
73,
Ron - WA9IRV
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