Anybody ever run coax down vent pipe????

[rasputen246]

:shock:

I am considering running my LTR-600 from the pvc vent mounted antenna down the vent. Naturaly I will do drip loops on both ends & seal it good on the bottom.

This will give me a straight drop to where I can go under the house & right back up to my "shack" (bedroom).

Am I missing some glaring error in this idea??
I will bring the coax out of the vent at a 90 on the lower end & will seal it well so the gas will not enter the house.

It will cut ~30' off my cable run & should get me within 6' of where I bring it back up thru the floor. :?

 

[TeRayCodA]

I did run a piece of 75ohm coax w/300 ohm balun outside the garage to the gutter,and the other end to a tv antenna mast,and it worked good!

 

[rasputen246]

I was lying in bed thinking "I can't do a 90 bend on LTR-600!".

But I will get gentle angle pvc "T" & pipe it up then reduce it down & black RTV the cable exit.

I envision cutting vent, dropping cable, instaling trap or 45 "T" then union then connecting it all back up. :roll:

 

[N_Jay]

you do not want the cable hanging vertically without support.

The weight will streach it!!!

 

[rasputen246]

you do not want the cable hanging vertically without support.

The weight will streach it!!!

I'm not that familar with LTR-600, but are you saying 20' verticle inside a pvc pipe away from wind & sun will stretch it that much???

Never considered that :roll:

OK, I'll ty wrap it to a 10' fiberglass fishing pole & J hook the top to the PVC . Do you think it could support 10' of it's own weight???

Second opinion on LTR-600 20' verticle stress???

 

[rasputen246]

DOH! LMR LMR LMR LMR

Don't know where I came up with LTR???

 

[jastx]

FWIW

When the house I am living in was built, a PVC vent pipe was punctured by a drywall screw. The flaw was not found until a heavy rain caused a large puddle to form on the floor. Fortunately, this happened before construction was complete. The builder spent a lot of time trying to figure out what was causing the puddle before finding and fixing the actual problem.

Just be aware that it is not unususal for rain to travel down the inside of these vent pipes and mix with the wastewater.

 

[rasputen246]

FWIW

When the house I am living in was built, a PVC vent pipe was punctured by a drywall screw. The flaw was not found until a heavy rain caused a large puddle to form on the floor. Fortunately, this happened before construction was complete. The builder spent a lot of time trying to figure out what was causing the puddle before finding and fixing the actual problem.

Just be aware that it is not unususal for rain to travel down the inside of these vent pipes and mix with the wastewater.

Thanks jastx,
Yeah I realize/planned for the rain that goes down the vent/drain.

I am planning on using a 45 or some low angle "T" fitting several inches above the drain + extending up & sealing it well with reducer/drilled cap & good ole RTV.

Thanks for pointing it out.

What ya think about the hang weight of 20' of LMR-600???
I really didn't consider that as an issue. :roll:

 

[N_Jay]

you do not want the cable hanging vertically without support.

The weight will streach it!!!

I'm not that familar with LTR-600, but are you saying 20' verticle inside a pvc pipe away from wind & sun will stretch it that much???

Never considered that :roll:

OK, I'll ty wrap it to a 10' fiberglass fishing pole & J hook the top to the PVC . Do you think it could support 10' of it's own weight???

Second opinion on LTR-600 20' verticle stress???

Most professional installations support the cable every 5 to 6 feet.

 

[rasputen246]

OK,
The weight of LMR-600 is 0.131 lbs/ft.
That works out to 2.62 lbs for 20 ft.

Sorry, I really dont think 2.62 lbs is gonna stretch it enough for it to make any difference for RX only use.
No reason to use such high quality cable except I will have it if I really need to try to get telemitry from Mars (joke) :wink: .

Now, IF I was talking 100 ft tower with wind you are correct. That would dammage it in both respects (weight&wind).

Maybe I didn't mention I am replacing a 50' RG59 B/U with a 30'(total run) LMR-600. Also new Scantenna replacing RatShack discone. Think I can live with it.

I thank you for your actuall correct advice, but as I am only hanging 20' & RX only I think I will chance it. :roll:

BTW: Heres a nice Coax Attenuation calc I found @ Times Microwave...My 30' run@860MHZ=0.7
http://www.timesmicrowave.com/cgi-bin/calculate.pl

 

[k0pwo]

Your idea is sound and will work fine. I have installed several pvc pipes in hew and existing homes that are used for coax runs for various types of communications systems. The only difference between what you are doing and what I have done is that the pvc on top of the roof was installed with several 90 degree bends in it so that the actual opening was facing down toward the roof so that water would not enter the pipe. All of these systems had at least 20' vertical unsupported runs and none have ever failed. In your case, make sure that you put a t like you propose in the pipe above the elbow so that your water will continue on towards the waster water pipe. Seal it really good and you will be fine.

Dave

 

[rasputen246]

Thanks Dave.

 

[Thayne]

One thing to consider is that plumbers sometimes run a snake down those vents to access drain lines where there are no clean outs easily accessible.
That would certainly snag your coax--then you wouldn't be considered a "plumber's friend" anymore

My plumber friend *****ed at me for connecting an air conditioner condensate drain into a vent pipe, but he got over it