• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

New to HF and looking at antenna options.

graywoulf

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Another thing occurred to me. Which is better, a north south orientation or east west orientation? Or does it matter?
 

W5lz

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On antennas lower than about a 1/2 wave length, antennas aren't too directional. At the typical heights for HF antennas, that 1/2 wave length height just isn't too practical. For HF antennas it's orientation is sort of dependent on the trees/poles/etc you have available to mount the thing. I've got one tree in my yard (and two or three in neighboring yards) so I use whats available and take whatever comes of it.
 

graywoulf

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Well, it took me a while to gather the parts and finally decide on a design but I now have a DIY ZS6BKW dipole antenna. My first ever antenna build at that. After looking at many designs and looking at other DIY antenna builds, I made my own version using (if you can believe this) a nylon cutting board I bought at the DT store. I used MFJ 450 Ohm ladder line and 14 Ga. stranded and insulated THHN wire. I also used brass bolts for terminals and all of the wire terminals were soldered on. I sealed it all with a combination of shrink tubing, silicone sealant, coax tape and electrical tape. I made a choke using 6 4" turns of the Wireman low loss RG-8X coax which I will cut to length as needed after the installation. This was fun to do and I do really appreciate everyone's information and encouragement in getting this done. Here are a couple of pictures. One is the strain relief/connection boards before I sealed them up and the other is the finished antenna. Now to wait out the rain to install this sucker. :D
 

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prcguy

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Looks fantastic! Great workmanship. But loose that coiled up coax choke, it will do a little less than nothing for that antenna. You need a very good and effective choke balun at the coax/ladder line junction.


Well, it took me a while to gather the parts and finally decide on a design but I now have a DIY ZS6BKW dipole antenna. My first ever antenna build at that. After looking at many designs and looking at other DIY antenna builds, I made my own version using (if you can believe this) a nylon cutting board I bought at the DT store. I used MFJ 450 Ohm ladder line and 14 Ga. stranded and insulated THHN wire. I also used brass bolts for terminals and all of the wire terminals were soldered on. I sealed it all with a combination of shrink tubing, silicone sealant, coax tape and electrical tape. I made a choke using 6 4" turns of the Wireman low loss RG-8X coax which I will cut to length as needed after the installation. This was fun to do and I do really appreciate everyone's information and encouragement in getting this done. Here are a couple of pictures. One is the strain relief/connection boards before I sealed them up and the other is the finished antenna. Now to wait out the rain to install this sucker. :D
 

graywoulf

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Looks fantastic! Great workmanship. But loose that coiled up coax choke, it will do a little less than nothing for that antenna. You need a very good and effective choke balun at the coax/ladder line junction.
Thank you for the complements!

I installed that coax choke as it was used in the YT video I got my plans from. It was said that it would keep any flowing currents from straying outside of the coax. I don't understand the theory of it but it was also said that the antenna may work with or without it. What kind of choke balun do you suggest that I use?
 

prcguy

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The wound up coax can reject RF at a particular frequency or fairly narrow band but you need something that is effective from 3.5 to 29MHz and that antenna can also be used on 6m, so maybe up to 54MHz. The wound up coax also reflects the problem back to the source, which is not ideal.

The only way to really fix the problem is with ferrite and that will absorb the RF instead of reflecting it back to the source. The best commercial 1:1 chokes I know of are made by MyAntennas. If you don't mind spending a few $$ this would really choke off the RF and isolate the coax from the ladder line: CMC-130S-3K - MyAntennas.com

If you want to roll your own, for about $7 to $9 buy an FT-240-31 ferrite toroid and wrap 9 turns of your coax through it right at the coax/ladder line junction. That should give a good 25dB and up to 30dB isolation between the coax and ladder line. You need this because a ZS6BKW or G5RV or similar will light up the outside of the coax with hot RF unless you provide a really good choke and both examples I gave will work fine.

Thank you for the complements!

I installed that coax choke as it was used in the YT video I got my plans from. It was said that it would keep any flowing currents from straying outside of the coax. I don't understand the theory of it but it was also said that the antenna may work with or without it. What kind of choke balun do you suggest that I use?
 
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graywoulf

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Well. I learned something new today. I found a FT-240-31 ferrite toroid core on eBay for around $14. Now, if I undo the coil I made and disconnect the coax from the connection point do I just wind the RG-8X around the core and leave it like that or do I need to build an enclosure to keep it dry? Or can I seal it up in another way without an enclosure? Thanks for your help.
 

K5mow

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I would put up a wire antenna like a G5 RV. Get yourself a manual antenna tuner. This will work very well on all bands.

Roger



Sent from my iPhone using Tapatalk
 

W5lz

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Just for grins...
Got an old TV laying around, the kind with a picture tube? Get in there and take the yoke off of the neck of that picture tube. Strip all the copper wire of off that yoke and you will find a ferrite core. No idea what mixture it is, but it's big. Easy to wrap gobs of coax through.
If you have infinitely more patience than I do, un-wrap that itty-bitty copper wire instead of cutting it off. No idea what you'd use it for but there's gotta be miles of it! I'd say un-wrapping that stuff would keep you out'a the bars, but when you're finished you will take up residence in said bars...
 

graywoulf

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I would put up a wire antenna like a G5 RV. Get yourself a manual antenna tuner. This will work very well on all bands. Roger Sent from my iPhone using Tapatalk
Hi Roger,

The ZS6BKW I built is an upgraded multi band dipole version of the G5RV. I do have a MFJ-949E tuner I will be using with it. I just need to get the balun choke right first.
 

graywoulf

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Just for grins...
Got an old TV laying around, the kind with a picture tube? Get in there and take the yoke off of the neck of that picture tube. Strip all the copper wire of off that yoke and you will find a ferrite core. No idea what mixture it is, but it's big. Easy to wrap gobs of coax through.
If you have infinitely more patience than I do, un-wrap that itty-bitty copper wire instead of cutting it off. No idea what you'd use it for but there's gotta be miles of it! I'd say un-wrapping that stuff would keep you out'a the bars, but when you're finished you will take up residence in said bars...
Well, two things about that suggestion. First, I don't have any old TVs to rob parts from and second, there are no bars where I live. :rolleyes: :D
I will have to order a core to get this job done. BTW, we do have a few places around that serve craft beer though. (y)
 

prcguy

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Here is one of the best prices I've seen on the FT-240-31 ferrite core at $6 each. Every year at Dayton I stop by Howard's table and get about $200 in ferrite products. Fair-Rite 2.4″ Toroid Core - Pro Audio Engineering

If your going to roll your own make two and put the second one at the radio end. You can sometimes lower the noise level into your receiver doing this.

On taking ferrite out of an old TV, that's ok but you need to at least measure its permeability or wrap some turns around it and see if it gives the needed choking impedance or isolation. That takes test equipment to figure out.

Well, two things about that suggestion. First, I don't have any old TVs to rob parts from and second, there are no bars where I live. :rolleyes: :D
I will have to order a core to get this job done. BTW, we do have a few places around that serve craft beer though. (y)
 

W5lz

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Don't know about Ma., or Ca., but if you can't find beer in Texas you just ain't look'n!
I have no way of testing for permiability so don't have the slightest idea of what it may be with that ferrite choke from an old TV picture tube. To be honest, I don't really care either. It's got to be somewhat effective at the least, and is only a "make do" thingy anyway. If it works in a particular situation.... Good! If not, then nothing lost.
 

graywoulf

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Thanks prcguy for the link to the cores. One thing I still need to know though. Will I need to build an enclosure for the core that will be outside? Or can I wrap it with coax tape and electrical tape to seal it from the weather? Thanks.
 

prcguy

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I've had several coax wrapped cores up for years with no enclosure, the ferrite doesn't seem to care about weather. They are fragile and will crack if they hit something hard, so use that as your guide.

Thanks prcguy for the link to the cores. One thing I still need to know though. Will I need to build an enclosure for the core that will be outside? Or can I wrap it with coax tape and electrical tape to seal it from the weather? Thanks.
 

graywoulf

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I've had several coax wrapped cores up for years with no enclosure, the ferrite doesn't seem to care about weather. They are fragile and will crack if they hit something hard, so use that as your guide.
Thanks for letting me know that. I was thinking that after I get the coax wrapped around the core and secured, that I would seal it with Plasti-Dip spray. I think that would seal it good and offer some protection otherwise as well.
 

prcguy

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I use small Ty-Raps to secure the coax to the core but if you do that be careful not to pinch off the coax and distort it. I use two Ty-Raps at each end criss-crossing the coax in an X pattern with just enough force to hold it in place. If you pinch off the coax you can make a filter that can have a frequency suck out that will reoccur at harmonically related frequencies.

Thanks for letting me know that. I was thinking that after I get the coax wrapped around the core and secured, that I would seal it with Plasti-Dip spray. I think that would seal it good and offer some protection otherwise as well.
 

graywoulf

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I use small Ty-Raps to secure the coax to the core but if you do that be careful not to pinch off the coax and distort it. I use two Ty-Raps at each end criss-crossing the coax in an X pattern with just enough force to hold it in place. If you pinch off the coax you can make a filter that can have a frequency suck out that will reoccur at harmonically related frequencies.
Thanks for letting me know not to over tighten the Ty-Raps. That is definitely good to know. Learned something new today. :)
 

prcguy

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To beat this topic to death, I had a contractor install a couple of small Ku satellite dishes years ago. The installation was beautiful and they tied the RG-11 coax down with stainless steel Panduit zip ties. They were perfectly spaced about 2ft apart and really tight. The end result was a satellite downlink with 20dB suckouts every 80MHz or so. The zip ties were crushing the coax and creating a filter. Placing a bunch of them at exact intervals reinforced the same frequency suckout and made it worse and worse with every zip tie.

The entire coax install had to be torn out and done right to fix the problem. I see a lot of the same thing in amateur antenna installs, so just be aware.

Thanks for letting me know not to over tighten the Ty-Raps. That is definitely good to know. Learned something new today. :)
 
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