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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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Ed Cregger wrote:
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. MFJ offers six window-mounted feed through panels for such. Their numbers are 4600-4605. MFJ-4600 has four balanced and two coaxial feed-throughs. 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. If one doesn't know what magnitude of impedance is being encountered by the balun, the best balun solution is a husky 1:1 current (choke) balun, not a 4:1 voltage balun which is designed to deal with 200 ohms, not 2000+j2000 ohms. -- 73, Cecil http://www.w5dxp.com |
#8
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![]() "Cecil Moore" wrote If one doesn't know what magnitude of impedance is being encountered by the balun, the best balun solution is a husky 1:1 current (choke) balun, not a 4:1 voltage balun which is designed to deal with 200 ohms, not 2000+j2000 ohms. -- 73, Cecil http://www.w5dxp.com ----------- I used to be good at this stuff, Cecil, but that was long ago. The only balun that has worked with any success so far has been the built-in balun (4:1 allegedly) in my MFJ-989C. That I can get to work. When hooking up other baluns and using the coax output on my tuner, none of the other baluns work worth a hoot with one exception. I have an LDG 1:1 200 watt balun that will tune my Van Gordon All Bander from one end to the other of the HF spectrum, using just the internal tuner of my Yaesu FT-890AT. Go figure. I used to be a fairly sharp cookie at this stuff, but those days are in the past. Got a serious case of "brick brain syndrome", if you know what I mean? To my way of thinking (which is probably incorrect), using the 4:1 balun would broaden the impedances that I could match versus the 1:1 balun. What you are saying is just the opposite. Please elaborate. I will be most grateful. Ed, N2ECW |
#9
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Ed Cregger wrote:
I have an LDG 1:1 200 watt balun that will tune my Van Gordon All Bander from one end to the other of the HF spectrum, using just the internal tuner of my Yaesu FT-890AT. Go figure. If this is the 80m dipole with 100' of ladder-line, one can look at my notuner all-band-HF antenna to see why 100' is a good fixed length for the ladder-line. 100' is near a current maximum point (loop) on all HF bands. If one varies the length of the ladder-line from 90' to 115', one doesn't even need a tuner and a 1:1 current- balun-choke is ideal. http://www.w5dxp.com/pnts130.gif To my way of thinking (which is probably incorrect), using the 4:1 balun would broaden the impedances that I could match versus the 1:1 balun. What you are saying is just the opposite. Please elaborate. I will be most grateful. A 4:1 balun is a very good transformer over a narrow range. Most are voltage baluns that do not balance currents and therefore do little to discourage common-mode currents. Test a balun looking into 2000+j2000 and see what happens. One of my 4:1 baluns got so hot I couldn't touch the case. The best balun design, IMO, is one where flux in the ferrite is caused only by common-mode current and not by differential-mode current. Here's some useful information: http://www.dxengineering.com/TechArticles.asp?ID={3E5220F7-2D0F-45B5-85F7-3B654F804C4F} -- 73, Cecil http://www.w5dxp.com |
#10
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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 |
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