I'm going to bury my coax soon under ground, at the present I'm using RG 213 coax and have a barrel connector inline as well......it's roughly 160ft coax on this antenna........I'm sure I need to go with a solid piece of coax, for this, would you use RG 213 coax, inside a pipe or direct bury coax ?......thanks in advance..
Coax cable ?
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Use PVC seal the splice just like it was going up the tower if you have no other options just leave it can be removed and replaced as a last resort. You would be better off replacing your coax now also seal every joint in the PVC to keep water out and use better coax than you plan.
What radio and antenna is this coax going to connected to?
What radio and antenna is this coax going to connected to?
prcguy
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I would not bury coax without conduit, rodents love to chew on it and if its not direct burial rated the outer jacket will deteriorate in the soil. I would also be careful about a splice, you would have to seal it as if it were going to be under water because the conduit will fill with water over time. Even non direct burial cables last a long time in conduit sitting in water, I've pulled out 30yr old cable from buried conduit and it still looks new after sitting in water for years.
gtaman
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If your going to bury coax is needs to be flooded or in conduit.
I plan on changing the coax out and use a solid piece.....what is the name of this conduit, really need something that will protect the cable, when it rains water runs off the hill out there where it is have a under ground stream ......also going to route the cable a different way than it is too, be a straight shot then....
prcguy
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PVC electrical conduit, the grey stuff at Homee Depot.
mmckenna
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Yeah, what he said^
If you are going to run all new cable, get the direct bury rated stuff. It'll last longer. Times-Microwave LMR-400DB. Eventually, may be several years into the future, the jacket will break down on the other stuff and your coax will fail, even if in conduit. Any water that gets in might contain chemicals, fertilizer, oil, all things that can break down the jacket.
Also, go larger than you think on the conduit. While you may be able to get LMR-400 into 1/2" PVC, it's going to be a pain to pull. The real labor/cost is in digging the trench. Lay in something bigger in case you ever decide to add more coax. Last time I did this, I put in 2". Didn't cost that much more, and the shovel made the trench plenty wide enough.
RidingDownUnder
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Yes I wouldn’t go less than LMR-400. With the length you described and if you’re going to be receiving 800MHz up to 1.2GHz then 400 would be ideal.
iMONITOR
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At 160 feet I would think loss would be a serious consideration even with LMR400. I'm curious why does the run need to be that long? No work-arounds, alternatives?
mmckenna
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He says he's using it for an end fed 10 to 40 meter antenna.
At 10 meters, loss is pretty low, a bit over 1dB.
At 40 meters, loss is really low, 0.5dB.
iMONITOR
Silent Key
I missed that somehow.
Good idea on using a continuous length without an underground splice to worry about.
Otherwise, unless you see a need for removing and replacing the coax in the future, just bury the coax and be done with it.
Either way you would have to use direct bury rated coax... water is going to get into the conduit regardless.
No need to dig a trench, just slit the earth with a spade and stuff the coax into the slit.
Had some direct buried RG8 here that was removed after over 20 years in service and it looked in better shape than the portion
that was exposed to UV all that time.
If you insist on using conduit, get electrical PVC at least 1 1/4"... yes, that big.
Otherwise, unless you see a need for removing and replacing the coax in the future, just bury the coax and be done with it.
Either way you would have to use direct bury rated coax... water is going to get into the conduit regardless.
No need to dig a trench, just slit the earth with a spade and stuff the coax into the slit.
Had some direct buried RG8 here that was removed after over 20 years in service and it looked in better shape than the portion
that was exposed to UV all that time.
If you insist on using conduit, get electrical PVC at least 1 1/4"... yes, that big.
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Regular coax is not direct bury.
iMONITOR
Silent Key
Gas or electric powered grass edger is great for cutting a slot in the lawn for coax. Stuff it down into the slot. It will close up in a couple of days!
Correct, "regular" coax may not be direct burial rated.
If you use coax underground be sure it is rated direct bury.
If your doing a "proper" direct burial, don't forget other things that might be buried there (ie power, gas etc...) the edge trimmer technique should be fine, do you have to use coax? for 10 and 40 meters maybe a different feed might be more efficient.
We used to do a lot of work with cables that were properly rated and had been buried, including 50 year old 12C12 (12 conductor 12 gauge) weather cables.
If you do decide to go with conduit, may I respectfully suggest you also plan for any future expansions you may decide on i.e. another antenna, maybe a couple of receiving loops etc... Give yourself space for expansion if you decide on it. Just an idea.
Also, if you are using a trench, it's "nice" to have it slightly sloped with a pit and a way to clean it out on each end (to drain water, and without the coax, to run a brush through to get rid of mold etc..).
As mentioned, the effort and cost of trenching is well in excess of the cost of enlarging the system to deal with future wants.
Also, a little on the crazy end of things, is 100'+ of conduit is a great earth tube length if you wanted to experiment with natural air conditioning and heating.
A little rambling, but I hope this was helpful.
Thanks
Joel
We used to do a lot of work with cables that were properly rated and had been buried, including 50 year old 12C12 (12 conductor 12 gauge) weather cables.
If you do decide to go with conduit, may I respectfully suggest you also plan for any future expansions you may decide on i.e. another antenna, maybe a couple of receiving loops etc... Give yourself space for expansion if you decide on it. Just an idea.
Also, if you are using a trench, it's "nice" to have it slightly sloped with a pit and a way to clean it out on each end (to drain water, and without the coax, to run a brush through to get rid of mold etc..).
As mentioned, the effort and cost of trenching is well in excess of the cost of enlarging the system to deal with future wants.
Also, a little on the crazy end of things, is 100'+ of conduit is a great earth tube length if you wanted to experiment with natural air conditioning and heating.
A little rambling, but I hope this was helpful.
Thanks
Joel
That is pretty far for coax. Long time ago I put a tower behind my house for 2M it was close to 200 feet of coax. It was strongly recommended I at least went to base of tower with heliax. I waited until I was able to scrounge some and was not disappointed with result.
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