[TowerTalk] cable entry to new shack

[Jim Brown]

On 8/12/2013 9:22 AM, Greg wrote:
> I am building a new shack.  It is 12x16 to stay under the limit
> needing a permit and is on skids supported on pier blocks, so there is
> room to maneuver under the floor.

First consider layout.  There is great benefit to holding the operating 
desk away from the wall enough that you can walk behind it to make 
connections to the gear.  When I set up my shack here in CA, it was 
shared space with my office, with desks on three sides, all against 
walls, with space for cables behind the desks. Having operated from 
stations where the desks have that space behind the gear, I would 
definitely use that arrangement if I were doing it again.

> Looking for input on pros and cons for running the conduit to the
> external antenna switch up the exterior wall and thru the wall or
> bring it up under the floor and cut an access hole for the PVC tucked
> away in the corner and seal it with spray foam.  I eventually plan to
> spray foam the entire floor from underneath for insulation.

I would try to make the antenna switching, and connections between it 
and the radio, as flexible as possible, so that you can reconfigure it 
for SO2R or M/2, or for different contests, and to accommodate more or 
different antennas.  N6RO has his antenna switching set up so that for 
160M contests, he can bring all of his antennas to the 160M operating 
position for use as RX antennas. The easier it is to do all of those 
things, the happier you will be.

Also, aim for a layout that accommodates good bonding of grounds. My 
shack is on the opposite side of the building (a garage with a 
"mother-in-law" apartment) from the breaker panel. I ran all the new 
power in EMT, but the route isn't very short because the floor is on 
slab and there are doors in the way, so I ran a perimeter ground ring 
around the building with rods by the panel, at intermediate points 
around the perimeter, and by the shack. Better to have power distro (and 
grounding of power distro) electrically closer to the operating desk if 
possible.  My antenna switching is under the operating desk, and the 
feeds to it come from a big copper entry panel in the wall right beneath 
the desk. That panel is bonded to the rods outside, to the conduit under 
the desk, and to the gear on the desk.

If power to this building comes from another building, you have two 
choices per NEC. The one I chose was to NOT carry ground between 
buildings (about 40 ft apart), only the two legs of 240V and neutral. 
This allowed me to bond neutral to ground in the second building. The 
alternative is to CARRY ground between the buildings, but neutral must 
NOT be bonded in the second building. Either way, both buildings need 
ground electrodes (rods, Ufers, etc), and neutral must be bonded to 
ground at the service entrance.

Another suggestion. If you didn't wire your home yourself (and even if 
you did), don't assume that the existing wiring is done right. Mine was 
a holy terror, lots of mistakes, both small and large.

73, Jim K9YC