Posted: 4/29/2010 5:24:36 PM EDT
Time to get that Carolina Windom antenna in the trees. Antenna will be 35-50' high and 100' from the shack. The last 75' to the shack will be under the fence and through the back yard. So the coax will need to be direct bury. I've got a little money to spend on this now, but I don't want to break the bank. I need the most bang for the buck coax. Opinions, please?
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you'll be sorry if you don't just bite the bullet and put 2" dia schedule 40 electrical conduit in the ground and leave a string running through the conduit. really sorry. trust me! 
buying 80' of 2" schedule 40 electrical conduit is peanuts compared to the amount of cursing you will do when you want to run a second coax. you don't even necessarily have to poke the conduit through the house, although putting an LB on the foundation or through a side wall makes it really clean. at home depot/lowes you can get 10' lengths, but at an electrical supply place you can get 20' lengths which are usually cheaper on a per-foot basis. or you can just skulk around construction sites in nearby developments... 
ar-jedi 
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Don't get plumbing PVC, get real electrical conduit. The elbows are larger radius, for one thing.
On the Windom, don't forget the Ferrite Beads on the feedline. You can get beads sized for 0.240" (RG-8X, LMR-240) or 0.400 (LMR-400, etc). For lowest band = 40 meters, you need 5 beads. |
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you'll be sorry if you don't just bite the bullet and put 2" dia schedule 40 electrical conduit in the ground and leave a string running through the conduit. really sorry. trust me!
THIS Since you're using a non-resonant antenna with a tuner, you need a good cable. Would recommend one of the LMR-400 types. |
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you'll be sorry if you don't just bite the bullet and put 2" dia schedule 40 electrical conduit in the ground and leave a string running through the conduit. really sorry. trust me!
buying 80' of 2" schedule 40 electrical conduit is peanuts compared to the amount of cursing you will do when you want to run a second coax. you don't even necessarily have to poke the conduit through the house, although putting an LB on the foundation or through a side wall makes it really clean. at home depot/lowes you can get 10' lengths, but at an electrical supply place you can get 20' lengths which are usually cheaper on a per-foot basis. or you can just skulk around construction sites in nearby developments...
ar-jedi http://www.farmtek.com/wcsstore/EngineeringServices/allbizunits/prodimages/full/lj1810a.jpg http://www.zpipedragon.com/Home/The_Shop/New_Garage/Phase_VII/electricalin2.jpg Exactly. At frequencies below 30 mHz your coax choice isn't too critical as long as its power handling capability is sufficient. |
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coax discussion (good read, INCLUDING COAX RECOMMENDATION TABLE) http://audiosystemsgroup.com/Coax-Stubs.pdf conduit discussion http://www.eham.net/ehamforum/smf/index.php/topic,58293.0.html ar-jedi |
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you'll be sorry if you don't just bite the bullet and put 2" dia schedule 40 electrical conduit in the ground and leave a string running through the conduit. really sorry. trust me!
buying 80' of 2" schedule 40 electrical conduit is peanuts compared to the amount of cursing you will do when you want to run a second coax. you don't even necessarily have to poke the conduit through the house, although putting an LB on the foundation or through a side wall makes it really clean. at home depot/lowes you can get 10' lengths, but at an electrical supply place you can get 20' lengths which are usually cheaper on a per-foot basis. or you can just skulk around construction sites in nearby developments...
ar-jedi http://www.farmtek.com/wcsstore/EngineeringServices/allbizunits/prodimages/full/lj1810a.jpg http://www.zpipedragon.com/Home/The_Shop/New_Garage/Phase_VII/electricalin2.jpg Looks like I'll be going by lowe's tonight after work to buy some 2" schedule 40 electrical conduit. Thanks for saving me from myself. 
ETA: I just printed out the PDF above, thanks. |
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Looks like I'll be going by lowe's tonight after work to buy some 2" schedule 40 electrical conduit. Thanks for saving me from myself. the 3" is in the next bin over. and the 4" is in the next bin past that. ... 
ok now i am going to tell you the bad part. see that white stuff on the ground in the picture above? well that's snow, my friend. and, our colleagues to the south are not aware but snow means cold as well. and, if you don't put the conduit down far enough, it is going to frost heave. in other words, as the ground freezes it will push up the pipe. it's just physics. per the NEC, for NM (non-metallic) PVC electrical conduit carrying AC voltages you have to bury it 12" down. in this case (antenna connections only) i don't think that would apply. however, i suggest that you get it down 12" to prevent it heaving from the ground freezing. ar-jedi ETA forgot one thing. without *perfect* sealing at the ends of the conduit, there is no possible way to prevent water from accumulating in buried conduit. the air in the conduit is colder than the air above the ground, so if the ends are "open" any moisture in the air will condensate inside the buried part of the conduit. so... take the lowest length of conduit and drill a couple of 1/2" diameter holes in it. when you bury it, wrap that section in landscape fabric (also called weed barrier, drainage fabric, etc) so that dirt can not block the holes and bugs/roots can not get into the conduit. a couple of shovel-fulls of gravel *inside* the wrap would be useful as well. it should look something like the pic below when you are done, minus the huge amounts of drainage gravel. 
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i suggest that you get it down 12" to prevent it heaving from the ground freezing. ar-jedi Can you come over and show me the proper technique of using a spade? 
I'm just glad the ground is still a little moist from the rain here lately. This ought to produce some good action photos.... stay tuned.
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http://home.comcast.net/~gregbell/Conduit Shack View.jpg http://home.comcast.net/~gregbell/Conduit Rev View.jpg 1) get a mark out done first.
2) the slide is going to have to go. 
3) lay a length of #6 bare copper wire in the ditch as well, makes a very good station ground. ar-jedi |
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1) get a mark out done first. Just a test fit.
2) the slide is going to have to go. YOU tell my kids that! Temporarily OK.
3) lay a length of #6 bare copper wire in the ditch as well, makes a very good station ground. Great idea! ar-jedi See if you can picture this.... This out in the woods, painted camouflage, protruding from the ground in the middle of a blackberry thicket. With the coax from the antenna slipping inside. The HOA Nazis don't know with whom they're dealing. (so far).
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The HOA Nazis don't know with whom they're dealing. (so far). i can't find the "you gonna get raped" jpeg right at the moment... lol. 
ar-jedi Just as long as it isn't like the Pulp Fiction - Ving Rhames violation. Butch: You okay? Marsellus: Naw man. I'm pretty f@#&*n' far from okay.
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Since you're using a non-resonant antenna with a tuner, you need a good cable. Would recommend one of the LMR-400 types. Quoted:
RG213 direct bury cable is available. I'm not sure if LMR is or if they offer a direct bury coax. I think this is what I'm going to use. Does anyone have any experience with LMR400DB (Direct Burial)? It costs $0.11/FT more than standard LMR400. I think I read somewhere that it is also called LMR400 "flooded". I'm probably going to get around 200' of some type of LMR400, and use any extra length for jumpers. |
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The HOA Nazis don't know with whom they're dealing. (so far). i can't find the "you gonna get raped" jpeg right at the moment... lol.
ar-jedi Got Your back dude! Here ya' go!!! 
(Finally there was something helpful I could contribute to this board, instead of just asking questions all the time.LOL! )
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Since you're using a non-resonant antenna with a tuner, you need a good cable. Would recommend one of the LMR-400 types. I think this is what I'm going to use. Does anyone have any experience with LMR400DB (Direct Burial)? It costs $0.11/FT more than standard LMR400. I think I read somewhere that it is also called LMR400 "flooded". I'm probably going to get around 200' of some type of LMR400, and use any extra length for jumpers. It is a good idea to use "flooded" bury grade coax, even if in a buried conduit. I selected DavisRF's Bury-Flex for outdoor and from another vendor have SuperFlex jumpers (with the clear jacket) for most indoor use. LINK TO Davis RF BuryFlex Page Since you are setting up from scratch, consider use of N-Connectors where possible. When you scan cables with a TDR (article on my TDR ) the N-Connectors are trivial impedance changes, where the typical PL-259 show an impedance bounce. The N-Connector is electrically connected even if the shield isn't mechanically tightened, which is a very nice feature that isn't there on the PL-259. Wherever possible I have used N-Connectors (including my remote antenna switch) and it has worked very well for me. I've had less luck using N-Connectors with the gear in the radio room, given the ubiquitous presence of PL-259 connectors, some die-cast in place, on Amateur Gear. So I have a mix in the shack itself. Units like the Alpha-78 were converted to N-Connectors (both RF in and out) when Alpha overhauled the amp for me. Some items I have been lazy and haven't changed over to N-Connectors yet (the Palstar AT4Km tuner, PowerMaster SWR/Watt Meter and the Flex-5000A). They will get changed eventually. On buying Coax, consider buying more - much more if possible - than what you think you need. It always comes in handy. I pulled doubles (Two BuryFlex, Two Rotor Control Cables, Two CAT-5 (Marine Grade) Remote Switch Control Cables) and a pull-line for future additions when I cabled in. Yes it cost a couple hundred more in materials, but I have easy redundancy and expandability in place. (article on my Coax & Cable installation saga ) YMMV, but set your shack standards (no point in spendy low-loss coax for UHF bands when you are going HF, that sort of thing) with a focus on performance rather than convention and brand name. Look at what commercial installations use, and serious contest stations spend their money on. 73 Steve K9ZW BLOG: With Varying Frequency - Amateur Radio Ponderings |
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looks like a downspout at the corner of the house? do you have standing water after a heavy downpour? with the trench open you could pick up some 3" schedule 20 pvc and route that water out the back as well. ar-jedi 
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looks like a downspout at the corner of the house? do you have standing water after a heavy downpour? with the trench open you could pick up some 3" schedule 20 pvc and route that water out the back as well. ar-jedi Yep, on both rear corners. Planning on trenching them out back as you suggested.
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looks like a downspout at the corner of the house? do you have standing water after a heavy downpour? with the trench open you could pick up some 3" schedule 20 pvc and route that water out the back as well. Due to the cold and frost depth, we had to go 6" drain tile 4-6ft deep. A neighbor has some at 2-3 ft down, and he has had them freeze. A bit confused on "Schedule 20" which would be a very light wall? A little more familiar with EB and DB PVC. 73 Steve K9ZW BLOG: With Varying Frequency - Amateur Radio Ponderings |
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A bit confused on "Schedule 20" which would be a very light wall? A little more familiar with EB and DB PVC. = DWV (Drain, Waste & Vent) I thought DWV was usually dual-marked Schedule-40 which would leave something like 3-1/16th Inches out of a 3 inch nominal (which if I remember right is around 3-1/2in OD)? Does DWV have flared ends? My underground run was short, but if I had made the "big arc" route (rather than loft space) I had been looking into 4in Sewer pipe to providing the segmentation to do a long radius and the ease of working with gasketed bell-flared mating ends. Anyone use Sewer pipe for their shack? 73 Steve K9ZW BLOG: With Varying Frequency - Amateur Radio Ponderings |
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It is a good idea to use "flooded" bury grade coax, even if in a buried conduit. I selected DavisRF's Bury-Flex for outdoor and from another vendor have SuperFlex jumpers (with the clear jacket) for most indoor use. LINK TO Davis RF BuryFlex Page On buying Coax, consider buying more - much more if possible - than what you think you need. It always comes in handy. 73 Steve K9ZW Upon further review, I ordered 200' of DavisRF's 9914F Bury-Flex for this application today.
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Is the windom one of the Radio Works ones? No, it's a home-brew I copied from one AFM made for a friend in college. Here's a direct link to the antenna building part of the thread. |
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1) get a mark out done first. Just a test fit.
2) the slide is going to have to go. YOU tell my kids that! Temporarily OK.
3) lay a length of #6 bare copper wire in the ditch as well, makes a very good station ground. Great idea! ar-jedi See if you can picture this.... This out in the woods, painted camouflage, protruding from the ground in the middle of a blackberry thicket. With the coax from the antenna slipping inside. The HOA Nazis don't know with whom they're dealing. (so far).
http://home.comcast.net/~gregbell/PVC Service Entrance Cap Side View.jpg http://home.comcast.net/~gregbell/PVC Service Entrance Cap Underside View.jpg I don't know if I would camouflage it or paint it to look like the head of a big snake sticking up from the ground....that might keep them away as well. 
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I don't know if I would camouflage it or paint it to look like the head of a big snake sticking up from the ground....that might keep them away as well. 
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Oh, btw, I'm getting ready to make this run myself.....so good learning material here. Great! Be sure to take pics....Everyone loves pics.
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I don't know if I would camouflage it or paint it to look like the head of a big snake sticking up from the ground....that might keep them away as well. http://img.dailymail.co.uk/i/pix/2008/02_03/snakehead_468x278.jpg
that should do it! |
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Quoted: Quoted: I don't know if I would camouflage it or paint it to look like the head of a big snake sticking up from the ground....that might keep them away as well. http://img.dailymail.co.uk/i/pix/2008/02_03/snakehead_468x278.jpg Quoted: Oh, btw, I'm getting ready to make this run myself.....so good learning material here. Great! Be sure to take pics....Everyone loves pics. DAYUM....that looks a lot like my ex-wife!! 
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That thought crossed my mind also!
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i must say that is nice work. you're coming with on my next elephant hunting safari –– they will never see us approaching if we each hold one of those up. ar-jedi |
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i must say that is nice work. you're coming with on my next elephant hunting safari –– they will never see us approaching if we each hold one of those up. ar-jedi Watch out for that tree! 
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| Well, the coax is inside the conduit and most of the conduit is covered back up. The last 10-15 feet to the shack are still uncovered to put in the grounding rods for the antenna and shack grounding system in this thread: Station Grounding / Lightning Protection Pic Thread. |
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