And in another video Peter explained, that the ladder line is very touchy about any metal i passes on it's way into the house. The Coax overcome that problem. Thanks for your channel Peter. I learn a lot. And I don't have any interest in antennas (I like to build the radio), so it is nice to get that knowledge so easy.
1. Make a home-made doublet from wire and rose clips. Drill two holes through the wall and feed wires through. 2. Use the same two holes and use threaded rods to go through the wall. Will also work with 450 slotted line. Space the holes at same distance as the width of the line you use. 3. Use 450 slotted line and squeeze through one hole. Impendace variances over short distances will not matter. With all 3 options, best use a symmetrical matching unit ie with the balun on the 50 ohm end.
Hi Tim, yes sometimes it is a better option but for my setup 4:1 works well. Either options solve the problem of terminating ladder line close to the entry point. 73s Peter.
@Tim can you help me here - I thought a 1:1 doesn't do any impededance matching - I thought it just attenuates any common mode currents? I thought a 4:1 would perform a 4:1 impedance match but *might* not attenuate common mode currents depending on the design. So if I had Z=50Ohm at the end of my ladder-line then using a 4:1 would generate an unnecessary impedance bump (at least that's what I thought)! Could anybody enlighten me please?
Kevin Polston it all depends on the impedance at the end of the ladderline. Tuners (auto especially) often struggle with low impedances which 4:1 could cause. That said, 4:1 often work well. It’s all down to the length of your doublet and ladderline.
@@M0XYM No "true" (ie not a choke) balun can prevent common mode current on the coax if the antenna is significantly unbalanced. Your feeder will really be part of the antenna and radiate, and if this causes problems, the only solution would be to run the balanced feeder into the shack and use a link-coupled ATU to do the balun transformation and balance correction. (edit) Or of course "do something" to the antenna to make it balance!
Anyone know how to use a vna with open wire? I want to be able to use the vna at the feedpoint of an inverted V. I have the MFJ Versa Tuner III which has terminals for the open wire on the rear. Perhaps i'll cut a hole in the wall the size of the tuner. lol
Okay, well that's it? Just use an MFJ-923? Well there's other options but they all cost a hundred bucks. What if I wanted to build one? What's in the black box? Is it such a mystery or does anyone know? Or do I have to buy a $100 MFJ-912 to and crack it open to find out?
How to pass Balanced line through brick wall - Answer: convert it to Coax and then do it. Not the answer I was expecting based on the title. Still looking for a way to pass balanced line through brick wall.
Oh dread! How to get the ladder line thru that brick wall? Buy an MFJ product & coax from him, of course! Now one has to get that coax thru that brick wall! And im sure he has an MFJ product to sell you for that... Is this the new Monty Python Show?
And in another video Peter explained, that the ladder line is very touchy about any metal i passes on it's way into the house. The Coax overcome that problem. Thanks for your channel Peter. I learn a lot. And I don't have any interest in antennas (I like to build the radio), so it is nice to get that knowledge so easy.
Thanks for the info
1. Make a home-made doublet from wire and rose clips. Drill two holes through the wall and feed wires through.
2. Use the same two holes and use threaded rods to go through the wall. Will also work with 450 slotted line. Space the holes at same distance as the width of the line you use.
3. Use 450 slotted line and squeeze through one hole. Impendace variances over short distances will not matter.
With all 3 options, best use a symmetrical matching unit ie with the balun on the 50 ohm end.
Thanks Peter. A simple solution re ladder line to the shack. 👍🇬🇧👍
73s Peter
this is how my brain read the title of the video: "Another brick in the wall" lol.
Nice one! 73 Peter
I find a 1:1 current Balun often provides a better match but have used 4:1 too. 73
Hi Tim, yes sometimes it is a better option but for my setup 4:1 works well. Either options solve the problem of terminating ladder line close to the entry point. 73s Peter.
@Tim can you help me here - I thought a 1:1 doesn't do any impededance matching - I thought it just attenuates any common mode currents? I thought a 4:1 would perform a 4:1 impedance match but *might* not attenuate common mode currents depending on the design. So if I had Z=50Ohm at the end of my ladder-line then using a 4:1 would generate an unnecessary impedance bump (at least that's what I thought)! Could anybody enlighten me please?
Kevin Polston it all depends on the impedance at the end of the ladderline. Tuners (auto especially) often struggle with low impedances which 4:1 could cause. That said, 4:1 often work well. It’s all down to the length of your doublet and ladderline.
@@M0XYM No "true" (ie not a choke) balun can prevent common mode current on the coax if the antenna is significantly unbalanced. Your feeder will really be part of the antenna and radiate, and if this causes problems, the only solution would be to run the balanced feeder into the shack and use a link-coupled ATU to do the balun transformation and balance correction. (edit) Or of course "do something" to the antenna to make it balance!
Anyone know how to use a vna with open wire? I want to be able to use the vna at the feedpoint of an inverted V. I have the MFJ Versa Tuner III which has terminals for the open wire on the rear. Perhaps i'll cut a hole in the wall the size of the tuner. lol
Okay, well that's it? Just use an MFJ-923? Well there's other options but they all cost a hundred bucks. What if I wanted to build one? What's in the black box? Is it such a mystery or does anyone know? Or do I have to buy a $100 MFJ-912 to and crack it open to find out?
How to pass Balanced line through brick wall - Answer: convert it to Coax and then do it. Not the answer I was expecting based on the title. Still looking for a way to pass balanced line through brick wall.
Would think you have to waterproof it pretty well Peter...from g4vvq
The inner is pretty well imprgnated - but extra might help. I have never bothered! Peter.
@@watersstanton I would be installing on a SW facing wall that gets all the weather, so would be better with a fully weatherproof Balun.
I’m after a 2m radio. Do you do a second hand range? Or something that won’t break the bank. Big fan of the videos. Thanks.
Harry, call Paul on 01702 206835 - he will help you. As an over 70, I am locked in at home!! Peter.
Thanks Paul. Hopefully catch you on HF sometime if you are at home ?
Over 70 Peter! Get away, at least we are benefitting from your time. Keep well 73 M0AZE
Thanks Mike.
Please double check, looking at the specs, this is not weatherproof
Yep...Install instruction #1. THE MFJ-912 IS NOT WATERPROOF.
I do not trust MFJ anyway
@@mauricewilkes826 It is a load of crapola
Oh dread! How to get the ladder line thru that brick wall? Buy an MFJ product & coax from him, of course! Now one has to get that coax thru that brick wall! And im sure he has an MFJ product to sell you for that... Is this the new Monty Python Show?
I am not sure that MFJ sell holes in walls! So maybe you can save the cost and make your own hole!