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#1
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I've read some Q&A about ladder line and I didn't see exactly my
question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg |
#2
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James barrett wrote:
How do I physically attach the ladder line to the house? I use electric fence insulators. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? No RF ground required. -- 73, Cecil http://www.w5dxp.com |
#3
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Some have tried using 1-ft lengths (or so) of PVC at the corners of the
house. Cut a slot in one end of the PVC, put a nail-hole or two near the other end - secure the line in the slot of the pvc using nylon ty-raps. "James barrett" wrote in message ... I've read some Q&A about ladder line and I didn't see exactly my question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg |
#4
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On Tue, 6 Jan 2009 14:00:43 -0800 (PST), James barrett
wrote: How do I physically attach the ladder line to the house? http://www.fishock.com/energizedFencing/insulators.htm http://www.fencesafe.com/insulators.html http://www.redhillgeneralstore.com/efwoodins.htm etc. Search for "electric fence insulators". If you want to be really creative, you could just build a spacer from ABS or PVC pipe, using a flange mount at one end, and a hole drilled in the pipe to support the wire. Maybe a plastic "T" at the end to support both wires on one insulator. Be creative. No ground required for a balanced system. However, methinks it's a good idea to ground the radio and the antenna tuner case. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#5
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James barrett wrote:
I've read some Q&A about ladder line and I didn't see exactly my question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg Use coaxial cable to get through the wall, then a BalUn outside to transition to the balanced transmission line. |
#6
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![]() "Dave" wrote in message ... James barrett wrote: I've read some Q&A about ladder line and I didn't see exactly my question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg Use coaxial cable to get through the wall, then a BalUn outside to transition to the balanced transmission line. -------- I'm running a Van Gordon All Bander dipole. It utilizes 450 twinlead from the dipole, thru the barrier into the house and connects to the 4:1 balun in my MFJ-989C manual roller inductor tuner. Instead of drilling a hole through the cinder blocks of my basement wall (finished), I made up a barrier insert from a piece of 2x4" lumber to fit under the lip of my window. I drilled two holes through the 2x4" lumber spaced at the same distance as the conductors in the twinlead. I then used a router bit to connect the dots. A very thin router bit. In fact, I think it was the bit from my cut in any direction saw that I bought several years ago and can't think of the name of it at the moment. They were all the rage on TV. It rotates like a drill bit or router bit. I hope you can follow me. I made the cut in the barrier board for the twinlead tight enough that I haven't even bothered to silicone up the gap, it is that tight. I haven't had any problems with it at all. No fires, no arcing, no scorching the wood. I think it would take a lot more power to do that than my 1kw Ameritron AL-80A can produce. Is it a PITA (Pain In The Ass)? Yes. But it gets me any band that I want, including six meters (in fine fashion too). If you go the coax route, you'll end up with a G5RV that won't take more than 200 watts without frying the twinlead, or you'll end up with a trapped doublet that only gives you a few kilohertz operating bandwidth on most bands. Chances are that some bands will be unusable unless you have a good tuner (no, not an autotuner - they don't have enough "swing"). Running a piece of coax into twinlead with an antenna with high SWR can generate high enough voltages to punch a hole through the coax' dielectric. After that hole has been made, the voltage needed to jump that arc from then on will be much lower, meaning that your signal will sound crappy and you may have problems with your rig. I put up with the 450 ohm twinlead all of the way into the house because it provides me with the most bands in the smallest space. It will also handle a kilowatt without protest. Oh, I haven't seen a 4:1 balun that is worth what it costs to ship to your door that sells for less than $139. I've gone through three brands lately. Brands that were supposed to be (and used to be) top shelf. Makes me wish I had held on to the good one that I bought years ago. That'll learn me. Good luck. Ed, N2ECW |
#7
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James,
Since it's been a while since ladder line has been in common use, there aren't many 'standard' ways of doing things in common usage anymore. So, as long as you keep a few things in mind, your imagination will supply you with any number of 'ways' to do things. Sharp bends, being close to metal things, and 'deforming' the feed line's shape too much are things to avoid. After that, it's more or less whatever you can think of, sort of. Lot's of 'wiggle' room in that, your millage may vary, etc. Good luck. - 'Doc |
#8
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In message , Dave
writes James barrett wrote: I've read some Q&A about ladder line and I didn't see exactly my question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg Use coaxial cable to get through the wall, then a BalUn outside to transition to the balanced transmission line. Baluns don't like 'funny' impedances. Better to use 75 ohm twin through the wall. If you don't have any lying around, maybe a bit of domestic twin power cable/cord could be pressed into service. -- Ian |
#9
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On Wed, 07 Jan 2009 13:22:19 +0000, Dave wrote:
James barrett wrote: I've read some Q&A about ladder line and I didn't see exactly my question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg Use coaxial cable to get through the wall, then a BalUn outside to transition to the balanced transmission line. I've had good luck bringing 450-ohm line through the window using MFJ's 4602 window feed through board. It has ceramic feed through insulators for the balanced line, more feedthrough's for a random wire, three coax lines and a ground wire. Even includes weather stripping and a burgler bar. Bob k5qwg |
#10
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On Tue, 6 Jan 2009 14:00:43 -0800 (PST), James barrett
wrote: I've read some Q&A about ladder line and I didn't see exactly my question. I want to run 450 ohm ladder line into the house. my tuner has a built-in balun for a ladder line so I think I can just run the ladder line all the way to the tuner. How do I physically attach the ladder line to the house? All I can think of is to nail it right through the spacers onto the side of the house. But I don't know if the nails will interfere with transmission at all. A second that comes to mind when considering this setup: if I run the ladder line all the way to the tuner, how do I ground it? Thanks, kb1odg James, You don't mention whether your antenna is resonant or not. Nor do you mention where your feed line enters the house. I use 600 ohm ladder line to feed my 220 foot dipole from Antenna tuner to Ten Tec L Tuner located near a basement window. There are a number of problems that I have solved since my antenna is between two trees about 300 feet apart. I support it using Dacron rope at both ends. One end is fixed. the other goes through a pulley to a 40 lb sealed box of cat litter. This helps to prevent the destruction of the antenna by wind- whipped trees. The antenna may be overkill: #10 copperweld and W7FY feed line. However, 40 lbs does not keep the antenna from flexing +-6-8 feet.. You need spring action of some sort to prevent the feed line from being ripped loose from the house or point to which it is first attached. I use plain string/twine to make an attachment from house to a spreader in the line. The string is adjusted so that the line is straight to the point where the string is attached to the house entry point and so that the line above where the string is attached is "draped" providing the ability for the antenna to go up or down 6-8 feet from its normal position. Under NE ice conditions it does drop that much and in high winds it can go up the 8 feet. I bring the line into the house through a basement window in which a Plexiglas insert has feed through insulators for external ground and the feed line. The string limits tension and flex on those insulators. Feed line from the insulators goes to the tuner when operating and to ground when not. There are feed line lightning arrestors that use spark plugs as grounding elements. I have not used these as I am worried that standing wave voltage nodes that I have on the line might trigger the spark plugs when running high power since I use the antenna from 160-10 on CW and SSB. If you have questions about my arrangement, I'll be happy to try to answer them. Ed, N5EI |
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