Antenna Feedline Interface Question

[W1RKW]

I'm trying to decide what to do with some antenna feedlines that enter the shack.  I'm trying to decide whether to go with a bunch of connectors on a plate mounted on the outside of the house sheltered by some sort of shroud or just run direct lines for antennas to the house through a hole.  Just curious what do you guys do? I'd like something that is clean and neat.  I'm thinking of going with the connector plate setup that way I can disconnect in the event of a T-storm.  Currently the 2 feedlines I have come up to the house underground and go underneath the bulkhead doors and basement door. I need to eliminate this mess of cables and create an airtight seal to my basement.

[K1JJ]

It depends upon how many cables you have coming in.

The individual outside junction connectors are FB for disconnecting during T-storms if you have maybe 6 or less.  Any more and I'll bet you get lazy and don't do it every time..  Since you have only two, I wud do it.. I mean, what the f**k?

I have close to 25 cables coming into the shack via underground 4" PVC pipe. It wud be impractical for me.  But over the years I've not had a problem with T-storms. I just disconnect the main junction coax jumper from the rigs and let the antennas snap to themselves when lightning flashes. Just one connection.  No problems.  I keep the rotator cables connected to the boxes. So far so good.

I know Chuck/KW has disconnects on his and lets them lay on the ground during T-storm periods.  Do it if ya have the motivation.

Some guys go the Polyphaser route too.

T

[KL7OF]

I went the simple route and bored a hole thru the wall with a  holesaw and lined it with PVC pipe.  I cut a couple trim rings from aluminum and used silicone caulking to seal the trim rings to the outside siding and inside sheetrock.... The coax cables (I have 11) run thru the pvc lined hole and I use a piece of stiff foam to keep the cold air and critters out.  It is easy to pull in a new cable ......I disconnect the coax at the antenna switches when lightning threatens.  Good luck...Steve

[WA1GFZ]

I removed the glass from a basement window and installed a 1/4 clear plexiglass type plastic.  Open wire line comes through the center small holes and coax and grounds through corner holes.

I ran open wire throught the walls with ceramic feedthroughs with long 1/4 threaded rods covered with a number of layers of teflon tubing.  there was a good gap around the conductors. Before that I set the wall on fire just shoving them through a 1/4 inch holes. good thing I spotted the smoke...after showing off QRO mode to a friend

[W1RKW]

Thanks guys. I think I have my solution.  It'll require rerunning buried cables but it's a project that can be done with another project that is looming for spring time.

[Glenn NY4NC]

Hi Bob;

I'm curious as to why the airtight seal?... I'm asking because I need to do the same thing... my reason? reduce the radon level in the basement before I start building the shack..

At my last QTH, I did the same thing Steve did, hole in wall, PVC pipe.. but the new QTH has cinder block (inside) and stone (outside) foundation. Not sure what I'm gonna do    How do you make an opening for coax cables in that! 

I need to eliminate this mess of cables and create an airtight seal to my basement.

[W1RKW]

Hi Glenn,
We didn't have an issue with radon which I'm happy about.  When the house was built the builder installed a nice weather tight door from the basement to the outside bulkhead. Having this door helps retain heat in the basement and makes the floors on the 1st level warmer. Some of the homes which were built by the same builder don't have these doors and our neighbors basements are much colder during this time of year. I'm also glad we have the door for security purposes as I don't trust the goofy locking mechanism on the bulkhead door and our backyard is pretty isolated from view.  All I need is for someone to break in and clean me out.  For extra security I added brackets to hold two 2x4's across the door.  The only way anyone will be able to get in is with a saws-all.

Right now I have my feed lines running underneath that door and out through the bulkhead defeating the purpose of the door gasket.  It's also a PITA when I need to go outside from the basement and having to move cables around.  During the winter it gets chilly in the basement and I can feel cold air at my feet when I stand next to the door so I want to get the threshold gasket sealed up and save a few more BTU's.

I 've sealed all the other penetrations and air leaks in the basement. I discovered all the leaks by help of several thousand ladybugs the first October we were here. With the leaks sealed up it's a bit warmer now but still gets pretty chilly in the dead of winter. Right now I'm looking at 56 degrees. Come February  it'll probably get down to 48 degrees without any supplemental heat.  It does warm up quickly when I run the radio equipment, computers and an electric heater.  I plan on heating the basement and the garage during the winter next year with supplemental solar heat, another of many future projects.  I only have one concern and that is getting the house so air tight the furnace can't "breath".

So to make a long story longer, I need to move the cables out of the way permanently. I just never got around to blowing a hole through the rim joist and run the wires out, mainly because I was in the middle of a construction project in the back of the house and wasn't sure how I wanted to do this. Now that the construction is done the cables can be easily placed.

Have you been tested for radon?  Is the level significantly high?

Bob

[W3SLK]

The notion of radon resonates pretty loudly here. I found out from my father-in-law, that after we left our previous QTH, (he was renting it to us), that the radon levels in the basement, (then the radio shack)were 48 picoCuries. I believe industry standard to be 4 picoCuries. I haven't had my new house tested for radon yet since it has only been a year since its been built. I may just get one of those kits for $15 just for some piece of mind. What prompted my in-laws to do this is that there had been about 4 people within a 5 square mile area that have passed away from cancer. None of them smoked or had high exposure to chemicals. By the way, the in-law's house was 42 pico Curies

[W1QWT]

For my 450 ohm transmission line I have a strapping knife switch outside my shack window in an enclosed box that switches the feedline to ground or into the shack. The feedline goes through ceramic tubes which are installed in the wall of the house. The co-axial antennas connect to a metal plate in the wall that have 6 inch long UHF bulkhead connectors that I bought from Cable Experts.
This way I can disconnect everything before it enters the house during thundering boomers.




Merry Christmas.
Q

[Glenn NY4NC]

We've been tested a couple of times before we moved in... Previous owners, home inspector and last owners... different readings every time. Once it was 3.8 another time it was 12, then 8.  I thought the average was high until I read Mike's post where his in-laws had a level of 42!!! Just to be sure I decided to buy an electronic radon meter and do my own testing. It just arrived two days ago and it's now setup in the basement right where the shack will be. This thing is pretty slick... updates level readings every hour and records short and long term averages. An alarm will sound if the long term levels get over 4 pico curies. $79 isn't bad for some piece of mind..
It needs to run for 48 hours the first time you plug it in before it gives the first level reading... should get my first reading by tonight. 

Hi Glenn,
We didn't have an issue with radon which I'm happy about.  Have you been tested for radon?  Is the level significantly high?

Bob

[W3SLK]

Yeah Glenn, the in-laws had both their house and the rental, (the one we were in until May) renovated by a contractor. His system, which is bored under the basement slab, vents the gas out to the atmosphere. There is a strip recorder installed to monitor radon build-up. Guaranteed to be below that of 4 pico Curies. Cost him about $900. I thought that was pretty good price for peace of mind.

[Steve - WB3HUZ]

Glenn sed:
".. but the new QTH has cinder block (inside) and stone (outside) foundation. Not sure what I'm gonna do    How do you make an opening for coax cables in that!"

HILTI


http://www.us.hilti.com/holus/modules/prcat/prca_navigation.jsp?OID=-12373

[Glenn NY4NC]

It says for "Wet coring in reinforced concrete".... I wonder if they will work through stone? 
We'll see if I can find a rental place around here...Probably mucho expensive to buy

Glenn sed:
".. but the new QTH has cinder block (inside) and stone (outside) foundation. Not sure what I'm gonna do    How do you make an opening for coax cables in that!"

HILTI


http://www.us.hilti.com/holus/modules/prcat/prca_navigation.jsp?OID=-12373

[Glenn NY4NC]

Thats exactly the type of system I will install here if the long term levels turn out to be above 4. That's actually a pretty good price from what I've heard... is that the system where a fan is installed in the vent pipe?

Yeah Glenn, the in-laws had both their house and the rental, (the one we were in until May) renovated by a contractor. His system, which is bored under the basement slab, vents the gas out to the atmosphere. There is a strip recorder installed to monitor radon build-up. Guaranteed to be below that of 4 pico Curies. Cost him about $900. I thought that was pretty good price for peace of mind.

[W3SLK]

Glenn said:

Thats exactly the type of system I will install here if the long term levels turn out to be above 4. That's actually a pretty good price from what I've heard... is that the system where a fan is installed in the vent pipe?

I believe so Glenn. The idea from what I gather is to bring the gas to the vent pipe before it can perculate through the basement slab and into living spaces.

[Steve - WB3HUZ]

It will go through stone too - even rebar if you are patient.

[WA1GFZ]

Then there is the issue of concrete. Say you live in a area where there is radon. The local concrete company uses local rock to make concrete.
I think you want to move air in the basement even vertical pipes to the attic to move a bit of air by convection so the concentration never builds up.
My concrete guy used 6 mil plastic under the slab so it is fairly well sealed. This is not a problem in either place but some friends have had to add circulation in their homes. one guy pulled air from under his basement slab to drop his levels below spec.

[Glenn NY4NC]

That's what a typical Radon mitigation system does.. a pipe through the slab into the dirt, with a fan mounted inside the pipe that sucks the air from under the slab...

You don't want to ventilate air out of your basement because that creates a low pressure area in the basement, just the opposite, if anything, you want air blowing into the basement to keep the pressure higher than the surounding earth.....but that creates other problems with your heating and air conditioning. The best way as you mentioned is to vent the gas to the outdoors from under the slab.

I got my first readings last night... a reading of 2 pico curies... Today it was up to three...
What I decided to do before investing in a mitigation system is to first paint the concrete floor with several coats of sealer, paint the bare cinderblock walls with waterproof sealer paint, silicone cauk all the floor to wall joints and seal any openings in the foundation or floor (drain pipes, etc..) then monitor the levels for a while.

 

This is not a problem in either place but some friends have had to add circulation in their homes. one guy pulled air from under his basement slab to drop his levels below spec.

[W3SLK]

My house is too new so it would behoove me to wait and let things settle first. I may be lucky since the the ground all around my house is loose shale. That is pretty porous ground. But it won't stop me from getting a test kit.