Jon's explanations below of what he has to go through to find the right
receiving antenna is not too untypical from a larger station. As I
mentioned in my "Patience in ARRL 160 Contest" post, Jon's post explains
exactly why those with weak signals need to be patient with regard to being
asked repeatedly to give their calls. It takes time to sort through the
antennas and directions to find the right one. And, of course, QSB and QRM
only exasperate the problem.
73. . .Dave
W0FLS
Tim,
I use a very cumbersome combination of switch boxes. One of the things on
my list to improve.
The primary selector is a B&W 3-position switch which in turn selects
three other six-position B&W switches. (I have about 18 Bevs in use!). The
3-position switch is marked for "W, S, NE."
The "NE" one selects the separate switch for Beverages (many are phased
pairs) at 5, 25, 37 (long stagger pair), 37 (long broadside pair), 45
(short stagger pair) and 75 degrees.
The "west" one selects Bevs at 210, 245, 290, 320 and 342 degrees.
The "south" one selects Bevs at 105, 162, 180, blank, short 320 and short
342 pair.
This setup makes it easy to quickly switch broadly around the compass with
the 3-position switch, and then narrow the choices with the six-position
boxes. Typically while running I'll have these set one of the 37/45
Beverages, the 180 and the 290. The latter two are single wires and thus
have a broader capture than some of the phased pairs.
Right these switches are a bit too far of a reach for contesting -- they
are above and slightly to the right of the main K3 transceiver. Better
would be right at the keyboard, ideally with push buttons. Maybe even
computer controlled on the screen.
The Beverages feed into the "Rx In" jack on the K3.
I also have a pair of short 1/8 wave spaced Rx verticals feeding a DX
Engineering NCC-1 phasing box. The output of this goes into the auxiliary
RX antenna jack on the K3 and this is used with the second receiver for
diversity reception. I can then tune the null easily with the large phase
control knob. But for some reason this weekend the pair is very noisy
compared to the main transmit antenna and I've mostly been using the TX
antennas for diversity reception. Sometimes I'll vary from this and use
one of the Beverages as the aux. antenna for diversity.
More switching is used for the transmit arrays. For my original parasitic
vertical array, one rotary switch selects NE, SE, SW, NW or Omni, changing
relays remotely out at the base of the elements. Now I have a new
broadside-endfire array and in it's development phase it takes THREE
different jury-rigged switches to switch from the original array to the
new one. I'll have that remedied before the next contest!
I'll post a photo shortly on www.aa1k.us under the "switching" section to
show these switches in the shack.
73/Jon AA1K
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Topband reflector - topband@contesting.com
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