Hi Mark:
Congrats on your new undertaking. A few comments:
>
> Greetings,
>
> My wife and I are having a new house built. I'm looking for suggestions
for
> things that I can do (or have done) during construction to help with
setting
> up my ham station at the new house. We have almost 4 acres and I am
looking
> forward to having a real 'antenna farm.' I think I've decided on the
tower
> / (initial) antenna setup. I want to use a Glenn Martin 70' tower with
Hazer
> as I want to be able to work on the antenna with both feet firmly planted
on
> terra firma. I plan on using a Force 12 5BA for 20 - 10 m. I currently
have
> a Force 12 C4S and really like the construction and performance. I'm not
> sure about 40 - currently the C4S has a rotatable diope element, I would
> loose that with the 5BA. For 80 and 160, I'm thinking a trapped dipole
> installed as an inverted vee from the tower. I've got enough real estate
> for a full length 160 antenna.
I don't know what a "Glenn Martin 70ft tower" (Rohn?) is but make sure it's
located so there are no obstructions for maintenance or future upgrades.
Stay clear of buildings, structures, trees, fences, etc. as best you can.
Antenna selection is not critical at this stage as they can always be
changed later.
Needless to say, install the tower system per manufacturer's recommendations
and don't overload it. You may need an engineer's stamp and permit prior to
installation. Check with your local building authority.
>
> The areas I'm looking for ideas with are grounding and getting the cables
/
> wires from the house to the antenna. The shack will definitely be in the
> basement. I and considering burying some ground rods under the basement
> floor before the floor is poured. That way, I would have an extremely
short
> RF ground (which is good, right?). However, I don't know if that is a good
> idea. I'm wondering why the electric service is always grounded outside
the
> house instead of through the basement floor. Also, this house will have a
> septic system an leach field, which I understand will consist of about
2000'
> feet of buried plastic pipe. I'm considering burying some wire for ground
or
> counter poise radials purposes along with the pipe. I'm not sure which.
I'm
> currently not contemplating a vertical antenna, but I hate to pass up the
> opportunity to get some wire in the ground. If I use the leach field as a
> counterpoise, I would probably want to bury insulated wire, but if I use
it
> as a ground, I'd want uninsulated wire. If I bury either insulated or
> uninsulated, I can envision that the copper will be in a pretty nasty
> environment (moisture, salts and bacteria), are there steps that I can
take
> to keep it from corroding away?
MOST important: Get a copy of The "Grounds" for Lightning and EMP
Protection, 2nd edition by PolyPhaser at http://www.championradio.com
and follow the advise. This manual should be in every ham's library.
It plainly answers many of the questions you have asked above.
I think burying small gauge wire, insulated or not, is a waste of time.
Depending upon your local soil conditions, the wire won't last more than a
few years. Guess how I know?
Spend the money and bury 4/0 cable around your house connected every 10 feet
to a ground rod with Cadweld connections. Tie your electrical service
entrance to the ground loop and also your tower grounds and shack entrance
panel to the loop. The shack RF ground is attached to the shack service
entrance and then to the outside ground system. This is explained very
well in the "Grounds" text.
I think the main reason you don't see ground rods driven through a basement
floor is to keep lightning strike current out of the house and away from
the TenTec equipment.
>
> What's the best way to get signals in and out of the house and leave me
room
> for expansion. I am looking forward to playing with different antennas and
> hope to make it easy to run new wires, etc. The basement walls will be
> poured concrete. I'm thinking of having them embedd some PVC pipe during
the
> pour to serve as sleeves for smaller diameter pipe and conduit which will
> eventually be run to the base of the tower. Not wanting overkill, but
> wanting room for expansion, what size pipe should I use? I plan on using
an
> antenna switch at the tower; which will reduce the number of coax runs. I
> know it's not a good idea to run electrical service in the same pipe as my
> coax, so I will bury a conduit for that. I don't think I 'need' 120V at
the
> tower, but I think it would be nice to have - especially for powering
tools
> when working at the tower. What about control lines for my rotator and
> antenna switch? I suspect that these will be 12 or 24 VDC. Can these be
> safely run in the pipe with the coax or in the conduit with the 120V? Or
do
> I need a separate conduit for them.
The short answer here is figure what you need and double it. Provide
separate PVC conduit access for coax and control cable runs. Configure
the conduit such that coax and cabling can easily be pulled in or removed.
You don't want cabling buried in the foundation or walls. Use 3 or 4 inch
conduit with long radius elbows.
Provide for a separate AC service from your entrance panel to the shack.
Don't rely on 15amp service or lighting circuits. Consider a 240vac/20 amp
minimum for the amplifier. Talk to a knowledgeable electrician and tell him
what your requirements are. Don't skimp here, you'll regret it later.
A 120vac service for outside tower work is a good idea. Run a separate
conduit. Follow your local electrical code.
>
> Also, should I run the coax / eletrical underground all the way to the
> basement from the tower, or should I bring it above ground near the house
> and then go back underground?
Depends on how the XYL likes it. Above ground is always easier to maintain
but it is diffucult to mow grass through a conduit run.
Consider water/moisture drainage and rodents getting into the conduit and
take steps for prevention.
I became a real believer in proper grounding a few years ago when lightning
struck a power pole two houses down the street from me and blew the
transformer apart. My tower was the highest structure around and
fortunately was not hit and no equipment was damaged.
Good Luck
Greg, K7KJ
Portland, OR
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