lmr 400 or lmr 400db
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Punkin Head
lmr 400 or lmr 400db
I am putting up a HF antenna and I am going to run the coax under ground from the house to the antenna, it will be about 150 ft from transceiver to antenna and maybe 100 ft under ground. I was told to get lmr 400db and some say that the lmr 400 is fine also. which do I NEED? I know that the lmr400db is almost double what regular lmr400 is. I dont mind paying that if I need to but if I dont need to then I dont want to. within the next year I will also have the ability to push 1kw thru it so that will be a factor at some point in the near future. Thanks guys.
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drdx
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Get the cheaper and use that cheap gray plastic conduit to house it in under the ground. It is like $2 for 10 feet and comes in bundles at home depot. Bury grade or not, the conduit will protect the coax from shovels and weedeaters better. Use that brush on glue for the section joining, and when it comes up out of the ground, make it come up and bend over like a cane where the coax comes out to prevent water. Buy several of those preformed curves for that part. Then, foam the end with that Great Stuff foam to keep everything out.
100 foot of conduit,fittings, and glue will run maybe $30-40, way less than the difference in the coaxes, and more durable.
-drdx
100 foot of conduit,fittings, and glue will run maybe $30-40, way less than the difference in the coaxes, and more durable.
-drdx
Yes it's me, Dollar-98, drdx, the original all maul, shot cawla on workin this no-fade technology.
-drdx
-drdx
why didnt I think about that -
SARGE
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linx
For the price difference (double) I'd get the strait LMR 400.
Call me a redneck, but wax-type center conductor insulator + heavy duty PVC outside coating = Good enough for me, lol. I don't have any of my coax under ground, but this stuff has a 20 year UV protection coating. It must be ok for under ground use. Yeah, it may get broke by the lawn boy, but just put it under ground far enough that they can't mess with it.
I have never experimented with the "off brand" LMR-400, but you can get a 500 ft spool on eBay for $185. I think that LMR-400DB (Times Microwave) is around $1.00 ft. The TM LMR-400 is around .50 cents a foot. I've heard good and bad about the cheap stuff, but most of the bad is just hear-say from folks saying "buy the name brand". Is mine name brand? Yes. Why? The nay-sayers scared the heck out of me before I purchased the off brand, lol.
Call me a redneck, but wax-type center conductor insulator + heavy duty PVC outside coating = Good enough for me, lol. I don't have any of my coax under ground, but this stuff has a 20 year UV protection coating. It must be ok for under ground use. Yeah, it may get broke by the lawn boy, but just put it under ground far enough that they can't mess with it.
I have never experimented with the "off brand" LMR-400, but you can get a 500 ft spool on eBay for $185. I think that LMR-400DB (Times Microwave) is around $1.00 ft. The TM LMR-400 is around .50 cents a foot. I've heard good and bad about the cheap stuff, but most of the bad is just hear-say from folks saying "buy the name brand". Is mine name brand? Yes. Why? The nay-sayers scared the heck out of me before I purchased the off brand, lol.
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Punkin Head
gonna go to home depot and get the conduit this weekend and make the measurements to where the antenna will be and get coax ordered (gonna go with lmr400 and run thru conduit) and hopefully my next weekend off in 2 weeks I can get "project get **Censored** off and cuzz at the antenna and everything around me until antenna is up or broke into a million pieces" under way lol. anybody wanna join in on the fun 
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linx
It won't be that bad. It's a fairly simple antenna. Looks like just some traps and tubing. You'll probably have to get the measurements down to a tee but that's probably all.
I just looked at the assembly instructions. I'm right...lol With all these HF antennas it's all about measurements. Get the wrong traps the wrong distances and you're screwed. Get 1/8" off on spacing between 1 trap and another and you're likely not to be able to tune those bands.
Plus, it's similar to my CushCraft beam. You gotta install the center conductor and shield physically on the antenna. There's no SO-239 to just screw into...which really shouldn't be a problem b/c that'll just be one less coax connector to install.
Have you installed coax connectors on this big coax before? This is for RG-213 but applies fairly similar to LMR 400.
Brought to you by the folks that sell $10k rigs...
[youtube][/youtube]
I just looked at the assembly instructions. I'm right...lol With all these HF antennas it's all about measurements. Get the wrong traps the wrong distances and you're screwed. Get 1/8" off on spacing between 1 trap and another and you're likely not to be able to tune those bands.
Plus, it's similar to my CushCraft beam. You gotta install the center conductor and shield physically on the antenna. There's no SO-239 to just screw into...which really shouldn't be a problem b/c that'll just be one less coax connector to install.
Have you installed coax connectors on this big coax before? This is for RG-213 but applies fairly similar to LMR 400.
Brought to you by the folks that sell $10k rigs...
[youtube][/youtube]
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'Doc
Running cables through conduit.
A very, very nice idea is to string a loop of string/rope/whatever through that tubing along with that cable. Makes changing or adding additional cables later much easier. Sharp bends and stiff cables don't mix well. Larger tubing is almost always better (more cables, and oh yes you will!). Weather resistant cable is better than non-weather resistant cable. That tubing will get water in it, count on it. And bugs, and animals, count on that too. Connectors/splices inside tubing is not a good idea, it will leak and you will have to get to it eventually (where that 'pull loop' comes in handy, right?).
Nothing here that's new, just something you may not have thought of yet.
- 'Doc
A very, very nice idea is to string a loop of string/rope/whatever through that tubing along with that cable. Makes changing or adding additional cables later much easier. Sharp bends and stiff cables don't mix well. Larger tubing is almost always better (more cables, and oh yes you will!). Weather resistant cable is better than non-weather resistant cable. That tubing will get water in it, count on it. And bugs, and animals, count on that too. Connectors/splices inside tubing is not a good idea, it will leak and you will have to get to it eventually (where that 'pull loop' comes in handy, right?).
Nothing here that's new, just something you may not have thought of yet.
- 'Doc
