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Archy
04-02-2022, 12:00 AM
25375x 63mm Fair-Rite #43 toroids with four passes of RG213. Choke is fitted to a newly built Moxon antenna.

JesseJamesDallas
04-02-2022, 08:46 AM
think I would used metal hose clamps instead of those plastic pull straps to hold things together...A year from now you will be taking it down to replace broken pull straps when those rot from the Sun and start braking...

Archy
04-02-2022, 09:22 AM
Using metal would be a really bad idea. The loops are spread out on purpose for stray capacitance, for one. The heavy duty cable ties are of commercial quality, they are UV stable. You would be surprised how long they will last. This is a practical solution for a very effective coaxial choke. The only thing I can see that could go wrong in the near future, is if the Cockies got stuck into it. Then again, they can destroy just about anything if they take a liking to it, and they are very intelligent. I'm talking about Cockatoos here in Australia of course.

Archy
04-02-2022, 09:34 AM
And by the way, I have had a wire Moxon up with a similar arrangement for over 2 years without a problem. In fact, the wire of each corner of the fibreglass spreaders is attached by a pair of much thinner cable ties than this. The Australian sun is some of the harshest in the world. We have summer temperatures well over 100 Fahrenheit. We have frosts here too below 40. So I am going to suggest that you do not know what you're talking about.

JesseJamesDallas
04-02-2022, 11:23 AM
And by the way, I have had a wire Moxon up with a similar arrangement for over 2 years without a problem. In fact, the wire of each corner of the fibreglass spreaders is attached by a pair of much thinner cable ties than this. The Australian sun is some of the harshest in the world. We have summer temperatures well over 100 Fahrenheit. We have frosts here too below 40. So I am going to suggest that you do not know what you're talking about.
Can tell you never been to Texas...:300 (97): That's Ok...If it works for you then great...

Alabama Buckeye
04-03-2022, 04:04 PM
#1 Ugliest Award "Ugly Balun" goes to Archy of Australia. A 5-30W Stout will be swallowed on your behalf. Congratulations.

Might I inquire the toroids used, should I endeavor to duplicate?

Archy
04-03-2022, 06:26 PM
Fair-Rite 5943003801 61mm toroid.
https://au.mouser.com/ProductDetail/Fair-Rite/5943003801?qs=Ca1fAiqt1aqdvI%252B3p7fLXQ%3D%3D

GobblerK5
04-05-2022, 10:17 AM
Nice idea and if it works, it works...who's staring up at the antenna anyway to care about appearance?

Sent from my motorola one 5G UW ace using Tapatalk

Archy
04-05-2022, 06:00 PM
It works. I think he was making a joke on ugly baluns, which this is not.
Innovantennas like to do this as a sleeve balun, but even if you put 25 ferrites on the coax, it won't have the choking impedance of this. You'd probably need more like 50, and then you'd be out of pocket. Each time you loop the coax, you square the impedance.

Alabama Buckeye
04-06-2022, 12:14 PM
Actually I presenting an award, a 5-30W stout to you Archie. Cheers. I'm exploring ugly baluns though I wish to adorn them and make them of minimal wind load. I want to place them right at the 8' antenna input where bracing is marginal.

I'm most interested Arhie with why mix 31 over 43 is a preferred, if so? VHF and UHF principally?

I brace my masts at 10'.

Archy
04-06-2022, 06:37 PM
Mix 31 will cover the lower amateur bands as well as 10/11m. 43 performs better from 10 and up, how high up, I do not know. I know this is vague, but I am not a ham, I'm strictly CB only. I don't even use UHF.
The other reason for #43 in that particular ferrite is availability, #31 is harder to source. Unless the ferrite fairies just delivered some for Mouser. By the way, the price of those has gone up dramatically, I previously bought them for under AU$7. Must be covid and the shipping the container crisis. Look at Element14 instead.
If you want to know how they perform at various frequencies, try YouTube. I believe there are some videos testing baluns and ununs using different mixes. The SWR curve may be directly relative to choking impedance??
The other way to find out is to read the article I was talking about. He did some fairly extensive bench tests, and there's a table on ferrites and windings for each band. The number of windings is frequency dependant, more windings is not better for optimum choking impedance.
I'll dig up that link, it's a must read for all radio operators.

Archy
04-06-2022, 06:43 PM
From page 34 there's the tables. Plenty of graphs to analyse too.
Enjoy the read!
http://www.w9joz.org/RFI-Ham.pdf

Alabama Buckeye
04-09-2022, 06:53 PM
Thanks Archy for the feedback. I too am most interesting in 11M band though I listen to VHF/UHF, for the most part, and 10M as well. I'm GMRS licensed, only need to pay the goobermint do do so, so a smidgen of UHF chatter is exchanged. GMRS license price also sky-rocketed, must be the increased shipping as well.

Anywho, what can anyone tell me about 9:1 Baluns; specifically what sort of antenna are they used with? I'mtrying Utube.com and find no explanation of what a single wire antenna is. I might assume a monopole like a 102" CB whip;
which wouldn't be the first time I'm wrong?

I've seen talk oflong wire antennas where a 9:1 Balun is spoken of meanwhile the Uboob speaker keeps moving the attachment point until finally he's end-feeding the wire and speaking of reaching 1000 ohms or more. What is the 450 ohm antenna that the 9:1 is translating to 50 ohm coax?

Archy
04-09-2022, 08:15 PM
I'm no expert, but I was talking to a bloke in Western Australia just yesterday about this. He was using a 40 odd foot inverted L antenna with a 9:1 voltage balun to a tuner. The antenna also had some ground radials/counterpoise.
9:1 and other ratios are typically used for high impedance end fed wires over a quarter wavelength long. In this guy's case, I think the aim is to step the impedance down to a region that is manageable with an antenna tuner. Also maybe to flatten the SWR curve for multi band use?? It means for a more flexible, usable antenna.
I have watched a YouTube video where they hooked up an analyser to various baluns and ununs. They recommended using a 1:1 current balun in conjunction with a 9:1 or 49:1, the 1:1 being after the voltage balun, radio side.
By the way, the guy in WA was using three of the 43 mix ferrites that I suggested, stacked together for good power handling.

mjd420nova
04-11-2022, 09:32 PM
One trick I learned over the years was that when the coax terminations are made, wrap them with the plastic electrical tape, then apply a coating of silicone around everything. That seals out moisture and a quick slice with a knife to split the tape to remove it, but when done properly, it will last twenty years in the harshest environment. I did hundreds aboard ships that were still intact after thirty when scrapped.

Archy
04-11-2022, 10:23 PM
This is wrapped with rubberised self fusing tape specifically designed for this application.