Drilling holes in the underside of the conduit puts this into the realm of French drains. Therefore, you need to lay the coax on a bed of coarse gravel (at least 1 inch of it) so that (a) water can escape, and (b) so that the conduit and holes don't silt up with mud.
@105d112 жыл бұрын
There is also the concern that roots might get in through those holes looking for moisture. I would not put as many holes as Dave suggests. One or two at the low point is sufficient. Also, use cable rated for direct burial (e.g. LMR-400DB), even if in conduit. Direct-burial cable has water-blocking grease in the shield. Conduit is classified as a wet environment - even if there is no direct water input, you will ALWAYS get condensation accumulating water in the conduit because it's always cooler underground. Your conduit will always accumulate water.
@davidsradioroom96782 жыл бұрын
I learned something. Thanks.
@josephrogers53372 жыл бұрын
In any area I would but an elbow in the pvc and bring it above ground. Seal with silicone but you eventuly will have water in side the pvc with temp changes causing it to sweat. A possible solution to that is some sort of tube inside to suck out any moister with a pump. then seal it back up.
@TahitiChris2 жыл бұрын
I built a 1/4 wave inverted L for 160 meters using a 4:1 balun and about 50' of RG-8 for the feedline. The antenna has an SWR of 1:1 on most of the band with an SWR of 1.2:1 at 2 MHz. When I tried to bury the coax, the SWR went above 3:1. Just an example of when burying the feedline may not work.
@albisasky7662 жыл бұрын
Well, Dave, like the Old Pillar of All Wisdom & Knowledge once told me, "The only thing that is completely waterproof is a frog's rear envd.
@dalekeener25332 жыл бұрын
like some other folks on this thread I have found water finds its way into the PVC . I had to lay a layer of gravel first and drill a couple small holes. worked great.
@W9HJBill2 жыл бұрын
I dug a 2 foot ditch and put in 2" PVC pipe and sealed it, then pulled 3 runs of DXE 400MAX coax in (which is direct burial). The coax has no connections and I put 90 degree elbows at the end then ran a 3 foot pipe going straight up and out of the ground and then on that put 2 90 degree elbows back to back (so that the coax come out the bottom above ground). It's been in the ground for 2 years now and no issues.
@RogerBrenon3 ай бұрын
Exactly.
@donaldsmith30482 жыл бұрын
Use electoral PVC and ues the sweeps, and lube. Glue it all together. Use a vacuum and pull line with something that the vacuum can suck through the PVC. Big PVC will make it easier to pull in. Try to get the PVC well above where water can stand. And if you can get where the ends will not get rain in them. There is a trick I use sometimes, Glue it all together, let it set in the sun. It will get hot and will bend as you put it in the ground, you will not need the sweeps to get the ends to come up and it will be a softer bend and easier to pull! DO NOT PUT THE PVC TOGETHER WITH THE COAX IN IT! YOU WILL GET THE PVC GLUE ON THE COAX AND IT WILL EAT THE OUTSIDE OF THE COAX!
@freddie3159 Жыл бұрын
Thank you for explaining in details. Easy to follow you.
@BowWowPewPewCQ Жыл бұрын
I'm not sure what kind of conduit you're running but I don't have water in my underground conduits. Of course, I put elbows and short stubs up out of the ground then another elbow and a cap with the correct tight fitting hole sealed with RTV. Maybe I'm missing something.
@larryfields26522 жыл бұрын
i have similar thoughts on this. I have mine running along side my house but thought of sending the coax through my wall but my son advised against it due to 2 things. 1 critters coming inside, Bob Heil mentioned using a shield like those stainless steel pads and 2 rain water coming inside.
@wildbill12 жыл бұрын
I dug a trench a few inches deep, layed down a bed of pea gravel, then a length of corrugated perforated drain pipe and ran my LMR 400 db in that. Been over a year now and has no issues
@DaveTheBigTomato Жыл бұрын
The conduit will NOT leak if you seal all connections and use weather heads on each end. It wil not fill with water and will not compromise the cable. I am in Florida. The water table is literally the ground. I use this method all the time.
@Robnord1 Жыл бұрын
That works for a while, but long term the conduit will have water intrusion. Did you know that plastic is a permeable substance...both PVC and ABS ? A surgeon who insists on nothing but old fashioned glass syringes clued me in to that fact years ago. On a molecular level, plastic is not impermeable.
@daviddurflinger31042 жыл бұрын
I run underground utilities all the time, I would suggest sealing your conduit at both ends with silicone after gluing the sections together with the whole thing assembled and dried place in a trench deep enough not to be disturbed by any thing, if it is sealed properly you should not have any problem.
@rgbailey2 жыл бұрын
check out leach line pipe, big enough for several cables, two rows of holes pre drilled. place several cords through it to pull additional cables, etc. Richard, KB7SGM
@richardjones12172 жыл бұрын
Dave, I have a Buckmaster DX off center fed dipole antenna with LMR400 Coaxial cable. Once buried, the cable will cross both my house supply electric line and the Comcast line. Will this be a problem? Thanks, KO4PHM
@anthonymarino42603 ай бұрын
thanks I will try that
@aaronfultz66532 жыл бұрын
Great video Dave. I'm setting up my first base station and needed this info. I have lmr-400 cable. Isn't lmr-400 direct bury? I bought mine at dxe, and their site says no in the specs, but other places say yes. I'm going to use conduit anyway, but was curious if you could bury the lmr directly. Thank you sir, you inspire and teach me. Aaron
@Robnord1 Жыл бұрын
Those who say yes are ignorant or pushing product to the ignorant. Only IMR 'DB' designation coax is suitable for direct burial.
@williambarrett702 жыл бұрын
I'm in Louisiana. In a rural part of Caddo parish (no counties in LA). My QTH has the blessing of being 280' above sea level. This helps my DX'ing beau coup! Thanks and 73.WW5MB
@davecasler2 жыл бұрын
For Louisiana, that's like being on a mountain top!
@00Klingon2 жыл бұрын
What if you fill the conduit with waterproof silicone grease? Would that be worth the expense and mess?
@RogerBrenon3 ай бұрын
LOL, NO, absolutely not, don't drill drainage holes in your pipe. You can connect as many pipes as you want and easily water seal them. Just elbow the ends up and down and your fine.
@richgolfs2 жыл бұрын
How about using a trench and expansion foam in the ground?
@timbacchus2 жыл бұрын
Make sure conduit has drain holes on the bottom.
@k8byp2 жыл бұрын
can and should. Just use Lmr 400 DB Good way to decouple lightning strikes. Sink them to ground Bad if it intercepts lightning earth currents though. VERY......
@barryinn17782 жыл бұрын
I disagree with you on that, now your allowing water moisture to seep in. I would seal up pvc conduit on all seams and run conduit up a wall to the overhang then seal up each end with silicone or similar after running coax. You could install a cap on each end with a hole just big enough to run coax through it.
@K2CTC2 жыл бұрын
Learning a lot here, thank you. Does it need conduit if it is in sand and very dry climate?
@K2CTC2 жыл бұрын
Cool! Just left you a message. Thanks much for all you do.
@alanhughes12622 жыл бұрын
i used flex poly water pipe seal the ends one comes up under my house the other just a little up the tower seal it up .
@Calico5string19626 ай бұрын
This is an older video, but I'm gonna comment anyway... You DO NOT want to drill holes in your conduit. BAD IDEA! This would allow water IN (as well as out) of your pipe/conduit - which is exactly what you are trying to prevent! Furthermore, don't bury the ends of the open (or sealed) pipe in the ground... the pipe needs to come out ABOVE the ground level. With an underground conduit run, you would need to use 90° "sweep" elbows at each end (specifically made for electrical conduit) - and NOT regular "pipe" elbows - to bring the ends of the conduit out above the ground at each end of the run. These sweeps are made with a roughly 10-12 inch radius (depending upon the pipe size) which allows for easy pulling of wire/cable/coax. Each end of the conduit run should then (ideally) be terminated into some type of a box or enclosure, to further prevent the entry of moisture, with the coax then exiting that sealed box and going on up to your antenna or into your shack. Another option is to use a "weatherhead" at one (or both) ends, where the conduit comes out above ground. These are readily available at electrical supply and home improvement stores (i.e., Lowe's, HomeDepot, etc.), and are specifically designed to let the wire(s) exit the pipe without the entry or rain (they can also be sealed with silicone, etc., if necessary, for extra sealing). Use a conduit or pipe that is sufficiently larger than your cable diameter. This will make the pulling - or pushing - of the cable much easier (and allow the addition of an extra cable if ever needed). I have two runs of buried conduit (each about 100'), from my antennas to my "entry box" where the grounding & arrestors are, and then the coax's enter the shack. I used 2" dia. PVC conduit, with a weather-head at the antenna end. The conduits have remained virtually dry for 4 years...
@201-Ryan2 жыл бұрын
Thanks Always Mr. David! I always enjoy you videos you teach a lot on things most don’t understand I’d say use pvc pipe or threaded pipe because they can be water sealed but even then the pvc can break a joint and leak in and threaded pipe best but more expensive but in my opinion would be best water tight pipe to run coax thru underground and not worry with water intrusion as much but probably would still be an issue no matter what you use water will always find a way in eventually
@201-Ryan2 жыл бұрын
Ki5TJL
@the1spyderryder2 жыл бұрын
That is really not a good answer drilling holes in PVC is a sure way for the coax to turn to mush. Water proof the pvc pipe and bring it above ground by 2 to 3 feet before bringing the coax out of the pipe. And seal it very well or bring it out inside an enclosure. One could use silica jell to keep the inside of the pipe dry. Another thing one could try is a moisture detector run the full length of the pipe inside these can be built using a FET. To alarm if moisture gets inside the pipe.
@buzzsah2 жыл бұрын
They sell direct bury coax. I did the same thing but with data lines, and 75ohm tv cable, they were both direct bury. Now, I was only running 35 ft, so I used 2-inch s40 PVC, 2, 45deg elbows, 2, 2-inch traps without the cleanout plug. At 35 ft, I ran it with a 3 inch slop with a 2ft deep x 1ft round hole filled with 3/4 stone on the low end. I used the 45's on the PVC underground came up then up from the 45 to 1.5 ft above ground using the traps up-side-down, keeping the rain out. It has been 12 years and still good. However, this year I will be redoing it, I think its time. lol Good luck.
@buzzsah2 жыл бұрын
O, ps, its 12 inches deep and at 6 inches I ran yellow caution tape, in case someone starts to dig.
@slowLFX2 жыл бұрын
Yes, yes you can. Dish technicians do it daily.
@HamRadio2002 жыл бұрын
mine is buried in conduit. it will fill up with water. I will vaccum it out in a couple years.
@AC3HT2 жыл бұрын
Dave, thanks for the good video. I really like the white board explanations/illustrations, as well. 73, AC3HT 📻🗼🎙️
@chirepia2 жыл бұрын
¡Muy buen video!, saludos desde Uruguay. Great video!, greetings from Uruguay.
@serve-Christ2 ай бұрын
Can coax go around the corner of my house
@aggie18712 жыл бұрын
Can i bury my ground radials under the ground? Someone told me no and someone said yes
@Robnord1 Жыл бұрын
Of course you can. Get good reference books like ARRL Antenna Book or others to verify for yourself. It's costly and a lot of work. My dad did it on only one of his many HF antenna setups, and swore to never do it again.
@pipedreams572 жыл бұрын
DAMN !!! Get on with it! Put it in 1/2" CPVC and caulk the ends with silicone.
@KE5ZZO2 жыл бұрын
Dumb question answer. If it says u yes u means underground ie rg-58u
@Spike-sk7ql2 жыл бұрын
Does it mean underground, or ultraflex? I just use direct burial cable. They make it in all kinds of cable. Milspec rg213, dxe rg8x is direct burial I think.