[HCARC] Ditching and Electrical To Antenna Farm

[Gary and Arlene Johnson]

I have 600+ feet of 2 1/2 inch grey conduit my neighbor gave me that I can 
use - regardless of NEC Code they are going in Grey electrical conduit. 
That should be enough for running approx 3 conduit runs up the hill to the 
antennas.  I was going to dig one trench for the electrical and one for the 
Coax unless I needed to run either one for each of the 12 volt DC and 110V 
AC, or one for each run of coax (was planning to have 2 conduits for the 
COAX).  The conduit is not the problem - the problem is how many and what 
wires in each.  If I have to run 3 I will or 4 or whatever is the best for 
the system.  I'd just like to do it ONCE if possible - get all the ditching 
done in one weekend - make sure the planning is good.

Bill Tynan indicated he thought that I should also run cable for an antenna 
rotator and that makes sense too.  I assume that would run in the same 
trench as the electrical, but does it have to go in a separate conduit?? 
BTW, where does one get rotator cable and do each type of rotator use a 
different type of cable??  How good is a Yeasu G-800 DXA rotator.  I think 
it is big enough for a Cushman A4S Tribander type antenna for the tower. 
Does a rotator use AC or DC current??

Dale - I built my own home and did my own electrical (and gas for that 
matter) and learned early on that it's much easier to pull a set of cables 
through a 10 foot section vs a 100 foot run (I was using home sized 
electrical cables - the heavy stuff for 200 amps).  Did it twice, once for 
the house service and once for the shop/garage service.  Since I have the 
conduit already at no cost, it will be the size I use - it's a matter of 
figuring out which wires go in which conduit in which trench.  Better I 
should ask and do it right vs doing it twice - that's kind of been my motto 
throughout this whole "Ham Radio Thing".  Since I have a K3 and it will soon 
have both receivers there is a significant chance of using  multiple 
antennas so I guess at least 2 runs of Coax are in order.  I have a 1000 
foot spool of LMR-400 direct bury coming.  Yes, I know it is overkill for 
HF, but my cost was less than RG-8 and I know that Bill Tynan will be 
smiling.  I figure why buy a really great, sensitive radio, put up good 
antennas, on top of a good tower, and not take as good care of all of those 
DB's as I can.

As for connectors - my radio wants PL-29's, so does part of the antenna 
tuner, and currently some of the antennas.  Kerry indicates it's almost 
impossible to completely waterproof Pl-259's - I have heard this before and 
understand it to be true.  Would it make sense to use his recommended N 
connectors on all of the outside fittings and just use the Pl-29's in the 
shack or will that cause some problem I don't know about??  It will cause a 
problem at the antenna selector switch as it wants Pl-259's unless I can get 
one from the factoiry with N connectors.  It probably would cause a problem 
with connections to a remote tuner if I ever go that way too.

Thanks for the help in doing things right guys.  I truly appreciate making 
as few mistakes as possible.  I HATE to do things twice.

Gary J
N5BAA
HCARC Secretary 2013


----- Original Message ----- 
From: "Kerry Sandstrom" <kerryk5ks at hughes.net>
To: "Gary and Arlene Johnson" <qltfnish at omniglobal.net>; 
<hcarc at mailman.qth.net>
Sent: Wednesday, February 06, 2013 5:36 PM
Subject: Re: [HCARC] Ditching and Electrical To Antenna Farm


> Hi Gary,
>
> You've asked a bunch of questions and none of them have short answers.
>
> First, the coax cable.  There are two basic ways water gets in to coax: 
> one is through non-weatherproof connectors and the other is through 
> "pinholes" in the outer jacket.  I'm not sure how the coax is specified, 
> but there is coax that is rated to not have pinholes.  That is what you 
> need for a long run buried or in conduit that might leak.  For 
> weatherproof connectors, you need to use Type N or one of its cousins such 
> as Type C.  When properly installed, these connectors are weatherproof. 
> UHF connectors are never weatherproof.  If you are concerned, avoid them 
> and learn how to use Type N's.  There are plenty around surplus and they 
> really aren't any more expensive than good UHF connectors.
>
> I would never run an AC power line alongside my coax.  First, I think 
> there are some safety issues and I would certainly consult the National 
> Electric Code (NEC) if I was going to seriously consider that.  I believe 
> the NEC may also require that power lines be run in a specific color/type 
> of plastic conduit.  I know the NEC is not enforced out here, however some 
> of their requirements are based on safrety issues and should be followed.
>
> The reason I wouldn't run them together even if I could is because of 
> noise pickup.  Power lines tend to be noisy and some of that noise is at 
> HF and VHF.  With the lines running next to each other for 200 or more 
> feet, there will be a lot of coupling.  I believe the LMR cables have a 
> single braided shield and an aluminum foil shield.  These materials 
> provide good shielding at higher HF and VHF frequencies, however, they are 
> very poor at shielding lower frequencies.  The main problem is magnetic 
> fields.  Low frequency magnetic field shielding requires ferrous metal and 
> lots of it.  If I expected to listen to the AM broadcast band or lower, 
> I'd be worried about power line noise.  It may even be an issue at 160m 
> and 80m.  Because of noise, I'd be reluctant to even have AC power out 
> near the antenna.  An extension cord may be a nuisance, but at least its 
> not a noise source when you put it away.  My antenna is 100 ft away from 
> power and, no, I didn't run AC power out there.
>
> I don't think you should need any more than #16 or #18 wire for the DC.  A 
> relay should be less than an Amp of current.  Many guys use bias-T's to 
> carry the low voltage DC down the coax to the vicinity of the antenna 
> where the relay is.  Be aware that there will be noise on the DC lines too 
> unless you have filters to clean it up.  Once you contaminate the area 
> where your antenna is, there isn't much you can do to clean it up.
>
> Lets see what this generates!
>
> Kerry
>
>
>
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