The AM Forum

I've seen articles on the web but cannot find them.  I need advise on how to feed COAX cables into the shack.  Not through window or using that MFJ thingie -- through the wall.  One suggestion is use PVC pipe and use 45 degree elbow to divert water.  I'm at the pre-framing phase of shack (walls not up yet)

Help

al

I've done the PVC in the past, works quite well.  I didn't put a 45 in it, though, I just drilled the hole with about a 20 degree downtilt towards the outside, and then put a coil-o-coax choke balun outside...  This was twofold in purpose:  It allowed me to make a "drip loop", and kept any RF in the shack down (I use ferrite at the feedpoints, so ....   I don't really think I had much in the way of RF on the coax.. BUT, it doesn't hurt to do it if the losses don't add up from the additional feedline, IMHO.

--Shane

Mount a grounded plate in the wall and use coax feedthrough connector.
This will divert any common mode current on the shields to ground. Just like a test chamber.
I replaced a basement window with lexan and drilled holes in the middle to bring open wire line in.

I'm  with Frank on this,  and have used a perimiter ground wire,  around the building,  with each end coming out of the soil below the plate,  and attaching to it.  For me,  # 6GA solid wire seemed fine,  but IIRC,  Frank was using # 4 GA.  If you believe in lightning arrestors,  think that they belong on that plate.  YMMV     Looks great so far.  GL   Vic

use a piece of steel pipe to pass the coax(s) thru the wall and connect the outdoor end to your ground system ... on the outside side choke loop the coax cable (similar to a coax balun) before entering the building ... the combination of these two as well as making the penetration fairly close to ground level are straight from GE station engineering notes and are excellent lightning stoppers (or at least slower downers) .... it has worked here for 20+ years

Al

The grounded plate with feed-through connectors is what I use.  I have six 8ft ground rods in about a 30ft dia. circle all bonded together with 4/0 AL wire.  The station ground system is then connected to the building AC grounded neutral with #2 copper.  I leave the coax jumper cables from the feed-through connectors to the equipment disconnected (at the feed throughs) when the station is not in use.

Fred

      Hey, it's 51watt Freddy !

      You have some FMing on your modulation...

Ralph

It's your ears that are FMing

My station ground is 3/4 inc copper tubing buried approx three feet under
ground give or take and it's 1600 feet long from the house to the road pot.

Get-R-Done .. 8)

73

Jack.

 BANG! !  Lookie here!!

SQUASHED, JUST LIKE A BUG! !  :o  ;D  ;D  ;D  ;D


Hi, Fred  ;D

The grounded plate isn't a bad idea.  Along with a healthy ground buss connection on the outside.  If you are using hard line, you could use the clamp-on grounding kits at the entry point.  With regular coax you could also add a feed thru barrel connector and also ground the shield at the entry. I'm not using that here, but I think I might add something like that to the arrangement.  I'm using 2" PVC pipe thru the outside wall with elbows (pointed down) on the outside to keep the water out.  I used the type of pipe connector with a screw-on cap and drilled holes in the caps.  I also added connectors on the inside with screw-on caps.  I filled the void in the pipes with fiberglass insulation (after stringing the cables thru the pipes).

All-in-all this arrangement has worked well for me and provided plenty of extra room to feed thru several cables.  I just used a hole saw to cut the holes in the side wall and sealed up with clear caulking stuff around the pipes. YMMV

73,  Jack, W9GT

Make a 4 inch hole!!!!!!!
It fills up fast. ALL your cables will go through there. Grounds, rotator cable (Yagi?) , future aerials, beverages, yada yada

My 3 inch pipeline to the utility pole is 100 feet long and it is filled with just 3 RG- 213 runs and a control cable for the rotor.

Fred

I have a 4 inch black pipe from home depot. Two pieces. The outside turns down.  It took 30 seconds to drill the hole. 15 minutes to Drag out the vacuum to clean up the mess. LOL

After I ran everything through this pipe, I used spray foam to fill the end of the pipe to stop bugs and spiders from comming in the house.  When I need to run a new line, I just reach in, pull a hunk of the foam out and then reseal. 

I see no way to do this better.  If you use a plate with connectors, Then you have exposed connectors outside.  Plus the loss the TWO connectors for each cable.  Maybe if you built a hinged cover over the plate with a rubber seal? I just dont like ANY kind of solder or crimp connector outside.  If it is, I use coax seal and really seal it tight.

My OWL just comes straight through the wall.  A dap of sealant is all thats needed there.

I have a Friend that ran some nice LMR coax from his shack to an outside weather proof box, this box contained electrical coax switch.  He can select any one of 6 antennas for different bands. I really like this approach.  But for me, I like to have my 2m/440 rig on at the same time my 10/15 rig is on and maybe my 80 meter rig.  I often reach over and turn volumn knobs up to see whos on what band. That means all these wires need to come into the shack.

C

Building codes in most areas around here REQUIRE any wires entering the building to be grounded at the point they enter the building.

Not sure how they'd like open wire line.   :)

I know that TV antenna coax, cable tv coax, telephone wire, electric service, satellite dish coax  at least are all on the list....

Yes,  I use 4" or 6" convoluted black drain pipe that comes in big rolls to run underground from my house to the tower (180' run)  that works great, but not to run thru the wall.  Big job to trench it in, but allows a neat installation with all the lines out of sight.  Another neat trick is to use a dryer vent thru the outside wall. The little hood protects it from water and you can use fiberglass insulation or foam , as you mentioned, or even rags to fill in the void after running the cable through the pipe.  You can trim it out on the inside to look really nice.

73,  Jack, W9GT

We dont have those codes in AZ.  Or, if we do, Nobody builds by them. The cable TV company came out to install new runs of coax, The Drilled holes in the side of the house, poked the wire through and put two nylon locking Grommets in :(  They also Wrapped the entire house in Coax. I was kinda pissed when I saw this but later just gave in.  They refuse to go into attics now. It can be 160F in there.

C

Geeze,
         all of the good suggestions here, buy noone has mentioned the foam in a can spray foam insulation. Most of that stuff expands as it sets up. After you shove the coaxes through the entry point "a little dab 'll do ya".  Trim off the excess after it sets up and you have a weatherproof (and bug proof) entry point.

the Slab Bacon

Yeah..the foam was mentioned...just got lost in the QRM

73,  Jack, W9GT

Kinda like 51w Fred in an AM QSO  ;D  ;D  ;D