[CQ-Contest] Contest Station Design - cable management

[Tom Rauch]

I'm going through this now, rewiring for the contest this weekend.

While I don't have a "real" contest station, I have a large 160
station we are using in a contest. I have six separate lines of
receiving antenna, a transmitter-signal nulling system that has
about one mile(!) of coax in the delay lines, nine wires of BCD data
going out to antennas for switching, and so on. Any antenna can
be picked at any of three operating locations, and at one location it
is stereo on two phase-locked receivers. There are three
transmitting antenna systems, and a lockout system for the
transmitters to keep the station honest.

When the feedlines and control cables for 80-6 meter arrays are
added to the above mess, it is a lot of wiring (but not as bad as
some multi-multis I suspect).

What I do is combine and switch everything possible at one point.
A single common point has the feed to EVERY receiver. A single
common point has every transmitting antenna. One RF cable now
leaves each common point to each radio for transmitting, one RF
cable for receiving, and one control cable for BCD coded switching
and control data.

When you slide each receiver out there are three cables and the
power plug. There is an audio buss (that runs audio to and from
every other receiver), an antenna input, and a control cable (muting
and sidetone, antenna direction and type, etc).

When you slide each transmitter out, there is an interlock/control
line, sidetone line, and RF output line.

My view is it is easier to run one control line out for 11 different
antennas, than to bring 11 antenna leads up to the receiver and
use a local switch. I also use BCD encoded control lines to
minimize the number of wires needed (three conductors can select
one of eight antennas, four can select one of sixteen antennas).

Since it gets down to three or four cables maximum to each
receiver and transmitter (plus "local things like keyers and mics)
wiring is a non-issue, the rat's nest stops at the hubs which are
near the feedline inputs. A side benefit is lightning is contained at
that point, since all cables (including power) can be common
grounded to one point. There is less to unhook to move things.


73, Tom W8JI
w8ji at contesting.com


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