kb2m@arrl.net wrote:
> I'm building a new home that will have a full basement. I'm going to move my
> shack into the basement and I'm looking for any ideas on how to bring in all
> my antenna cable's. I have about 12 antennas total. Cable's will consist of
> mostly RG-8, but two of the cables are hardline, one 1/2 inch, the other
> 5/8. The new house will be about 20 feet away from my tower.
>
> I was thinking of mounting a grounded plate to the tower, and then attach
> all of the cables.
I ground the shields at the top and bottom of the tower. This can be
done using a bulkhead connector, or there are more elaborate methods of
wrapping the shield and tower leg with copper sheet. I choose the easy
way and use bulkhead connectors through a piece of 1 1/2" X 1/8"
Aluminum angle clamped to the tower legs using saddle clamps on each end.
> I would also mount lightning suppressers at that
> location.
Most arrestors will not stand up well exposed to the elements which I
saw already mentioned.
> I would then run short 20 foot cables into the shack via a buried
> conduit. What should I use for the conduit?
Depends on code in your area. I used 4" PVC
> Does mounting (and grounding)
> all the antennas to the Tower make sense, or should I do this just outside
> the house?
I do both, with the arrestors located at the bulkhead plate where the
cables enter the house.
http://www.rogerhalstead.com/ham_files/cablebox.htm shows my old
installation and the new with the smaller bulkhead box. The system has
changed again with larger boxes at each end of the conduit and two
entrances at the shop.
The second time I chose to go through the end plate instead of the
basement wall for two reasons. One, it maintains the basement wall
integrity whether poured or of concrete block. Second: mounting the
entrance box on the end plate makes for an installation that is easily
removable and repairable if you decide to move. Neither of which is easy
to do with a hole in a concrete wall. Now if I had brick veneer or a
true brick home the basement wall might be a much more attractive option
for the entrance and particularly molding the conduit into the wall.
As we are only talking a single installation with 5 coax for the
station, 4 RG-6 for the satellite and OTA TV, and 5 control cables
including one 8 conductor rotator cable I was able to get away with 4"
PVC. My feedlines are all LMR-600. from the stations to the junction box
at the base of the tower. From there they go to either the remote
antenna switches, or the grounding connectors at the base of the tower.
It's also LMR-600 from the base of the tower to the top and the 160 half
sloper. I will be using Davis Buryflex pigtails to the antennas in the
array at the top of the tower. However from the remote antenna switches
it's *sometimes* as small as RG-8X with shield plus foil, or CNT-240.
Two of the leads to the half wave slopers are BuryFlex and one is LMR-400.
I want the Polyphasers right at the house entrance. This does at least
two things. It means any induced voltage pulses at the tower will be
smaller by the time they reach the bulkhead at the house entrance and
the Polyphasers will have a less powerful pulse to deal with. It also
puts the protection close to the rigs so voltages induced into the house
are more effectively bypassed to ground.
73 and good luck
Roger (K8RI)
> Any and all input appreciated.
>
>
>
>
>
> 73 Jeff kb2m
>
>
>
>
>
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