[SBE] "modifying co-ax" to drain moisture

[Rod Zeigler]

Dean,
You have at least one, if not a number of issues here. First, heating 
and cooling over the day will draw in atmospheric air which has water in 
it. This condenses and collects at the lowest point. Drilling the hole 
was "first aid". Losing a bottle in an hour indicates a VERY large total 
leak, assuming you are only pressurizing the line to 1 or 2 PSI. If you 
have put a large pressure on it, you may have blown seals. Also, make 
sure you seal your weep hole after you have drained your co-ax. Rubber 
material and hose clamps should work temporarily.
A dehydrator (compressor and dryer) is life support. It can get you by, 
but you now have another system to maintain, and they WILL quit if used 
with a heavy duty cycle, which it sounds like you will have.
The only way to really fix the problem is to have an experienced person 
climb the tower and inspect the line AND antenna. Hopefully they can 
take patching materials along with them to temporarily stop the leaks. 
After this is done the climbers report will give you the information you 
need to make the decisions necessary.
You mentioned nothing about age. That can be a factor, but with a leak 
the size you mentioned, it seems that you have a big problem that will 
not go away any time soon without some TLC to your antenna and feedline.
Rod
On 10/3/2012 11:38 AM, Dean wrote:

>

> I have a 300 foot run of 1-5/8" air-filled coax up one of our towers 

> that apparently has a bad seal at the top end, and it seems to be 

> admitting water ...

>

> I can give the co-ax a blast of compressed nitrogen, and after about 

> 15 seconds the water is "forced out" through a small drain hole we 

> have drilled in the co-ax jacket and outer conductor,...

>

> My problem is:  I cannot leave the co-ax pressurized or the leaky 

> seals at the top will bleed down my bottle of nitrogen in a short time 

> (about an hour or so).  So, whenever it looks like a rainy siege is 

> coming, I give the co-ax a "blast" of nitrogen, and hope it will keep 

> the water out for the duration of the rain storm.

>

> What if I increased the size of my co-ax "weep hole" to about ½ inch 

> diameter.

>

> What if I coupled a small air compressor (with a dryer attached) 

> operating off 120 volts to the co-ax and left it running (cycling on 

> and off on pressure)?  Would this work?

>

> I'm looking for a long range answer, without having to climb the 

> tower, replace the co-ax, etc.

>

> Any suggestions?

>

> DEAN SPENCER

>

> *WBIW/WQRK/WPHZ*

>

> dspencer at hpcisp.com

>

> P.O. Box 1307

>

> Bedford, IN.

>

> Ph.812-275-7555  Fax 812-279-8046

>

> Cell 812-797-3612

>

> wbiw.com  superoldies.net

>

>

>

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-- 
R. V. Zeigler, Dir. of Eng.
Nebraska Rural Radio Assn.
KRVN-KTIC-KNEB
Newsletter: http://tinyurl.com/RRNnews


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