Hi Bob
You may want to download the Motorola R56 pdf file online. Also QRZ dot com
has a 3 part forum on station grounding hosted by a PE who installs and
inspects cell tower sites. Both are a very interesting and informative read.
Whenever I pass coax or hardline through box enclosures or panels, I find 1/2”
- 1” J-cord connectors work great in keeping out the insects and moisture. Just
pick the size that suits your feedline diameter. They are available in standard
and Liqui-tite. Home Depot and any electrical supply house usually stock them.
Usually #4 solid copper wire is adequate for grounding.
Hope this helps you out some.
Bob Matthews KT3RR
Sent from my iPhone
> On May 30, 2018, at 15:07, Fred Keen via TowerTalk <towertalk@contesting.com>
> wrote:
>
>
> Hi Bob,
> I like the MFJ 4603 thru window approach. If your window is not wide or tall
> enough to get all the connections with it, you might consider making one with
> plexiglass,
> see one here: Building the shack - window feed thru panel done!
>
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> Building the shack - window feed thru panel done!
>
> Plexiglass window feedthru panel
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> Be sure to post some pictures of your antenna farm.
> Fred KC5YN
> On Wednesday, May 30, 2018, 1:04:14 PM CDT, Bob Shohet, KQ2M
> <kq2m@kq2m.com> wrote:
>
> I am planning to completely revamp my station placement and station ground
> and have been thinking about and researching different ways of doing this for
> several years. I have also studied what was done at many stations at which I
> have operated, but that only confuses the issue more as each house and
> terrain is different and every station owner has their own way of doing
> things. :-) I have also spend considerable time reading the Polyphaser
> material and W8JI and K9YC’s websites. So I have several questions and would
> appreciate your help.
>
> First, here is what I am planning to do:
>
> Install a metal Hoffman box at each tower and then ground the coaxial cables,
> rotator cables and control cables at the box (the control cables are already
> grounded to the tower) with a #2 Copper wire grounded connecting to multiple
> short ground rods (because of the ledge right underneath) and the tower.
>
> Then I will run all the cables to a larger metal Hoffman box grounded just
> outside the shack and a few feet from the utility ground, telco and cable
> grounds. Then, in a trench ~ 1’ deep around two sides of the house to form a
> perimeter ground, I plan to connect a series of 8’ copper clad ground rods
> culminating with a connection to the Hoffman box outside the shack and to the
> utility, telco and cable grounds, so that I will have a single-point-ground
> connected to a perimeter ground in the trench. I will then fill in the
> trench when done.
>
> Questions:
>
> 1) How far away should the trench be from the house foundation? 6”? A foot?
> more? I know that there should be some separation but do not know how far
> is best. I live in Western CT near the NY border where we get a lot of ice
> and snow and it has gotten down to –20 F; so frost heaves are always an issue.
>
> 2) I assume that the best and safest way to connect all the grounds would be
> to use #2 copper wire running between the Hoffman box and the utility/telco
> and cable grounds. Since these ground wires are all connected ABOVE ground,
> is there any risk to removing the wires and replacing them with a single #2
> Copper wire below ground? If there is risk with removing the utility ground
> temporarily to do this, then should I simply dig down and then connect #2
> copper wire to the same utility ground rod below ground – thus avoiding the
> need to remove the utility ground above ground to connect all the grounds?
> Is there a problem that could be created by having an oxidized copper clad
> ground rod of the utility ground with connection above ground and then simply
> sanding a spot lower on the same rod below ground in the trench and then
> connecting the Hoffman box to that below ground?
>
> 3) I need to get about 6 control cables, 6 rotor cables and 8 coaxial cables
> into the shack. How would you suggest that I do so without allowing critters
> and insects in?
>
> I see two potential options:
>
> A) There is a small window to the shack about 12” high and 24” wide – if I
> replaced the window with an aluminum plate (which would be grounded to the
> single point ground), I will use standoff coaxial connectors to get the
> coaxes inside, but I don’t think that I have enough room to mount everything
> on the plate, so how do I get the control cables and rotator cables inside
> without making another hole and allowing the critters in?
>
> B) If I don’t replace the window with a panel, then how do I get all the
> cables inside without allowing critters and insects inside other than making
> a big hole in the house above the top of foundation and then stuffing it with
> steel wool and other material? This would allow cold air and humidity to get
> into the basement as well and provides a potential way in for all kinds of
> insects and mice. Not a desired outcome.
>
> 4) Due to the extremely violent wx that I get at my qth I still like the idea
> of disconnecting everything when not in use. With this in mind, does it make
> sense to have another aluminum panel inside the shack mounted on wooden beams
> near the window (and grounded to the spg with #2 wire) to which I attach all
> the coaxial, control and rotator cables inside the shack and then simply
> disconnect them and move them away when not in use? These outside and inside
> cables would also be disconnected from all the equipment and outlets and
> ground inside the shack would be disconnected from the single point ground
> outside.
>
> I would appreciate any thoughts, suggestions or warnings about what I
> propose. Thank you for your help!
>
> 73
>
>
> Bob KQ2M
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