Multi-band, Low-loss, works without ATU. ZS6BKW: is it my new POTA antenna?!

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This is ZS6BKW antenna. Ham Radio antennas for HF portable use need to be unique , in a way: easy deployment, high efficiency, simple construction, less various baluns and transformers and coax cables as possible. There is not so many such antennas. ZS6BKW is one of those. It’s a cousin of well known G5RV antenna but with much better specs, as it’s design based on computer-modeled best lengths of 450 Ohm windows-line feeder and the dipole arms. The idea of using transmission line as an impedance transformer was anticipated by Louis Varney, G5RV back in 1950’s, and then developed with much more precise computer calculations by Brian Austin , G0GSF, in some 1980’s and was named ZS6BKW Antenna, as such was a callsign of B. Austin at that time. The ZS6BKW project is kept on developing constantly by other hams. My version is based on an article in the www.dl9nbj.de blog and is adopted for the 450 Ohm window-line use.
My field test shows that this antenna can (in my particular location and configuration!) work good or satisfactory without the tuner on 40,20,17 and 12m bands, and with the ATU it can tune all the bands from 80-10m with no problems. The best results were achieved when used together with the 1:1 Balun. The tuner used was an in-built Elecraft KX-2 ATU. Some further experiments will be conducted to test the manual Z-match or similar , balance-line-ready tuner. Stay tuned!
I designed my own 3D-printed Dipole Centre for this antenna. STL file is available on my printables.com account:
www.printables.com/model/6213...
Here are some links to my other videos, explaining some aspects of this video:
Spiderbeam 10m mast
• New Spiderbeam 10m Min...
My favorite knots in ham radio
• Knots for Ham Radio. M...
Please consider subscribing if you like my videos.
Please hit the Thanks button under the video, or Buy me a coffee if you want to support this channel:
buymeacoffee.com/ly2h
73! @Linas_LY2H

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Опубликовано:

20 окт 2023

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Комментарии : 26

@davidshermanlittle919 Месяц назад

Thank you for your knowledge and opinions.

@jamesttk488 8 месяцев назад

I didn’t know that it is not necessary to connect a coax to this antenna and now I know. Thanks very much.❤

@ronjoseph7973 7 месяцев назад

I’ve been using a commercially built ZS6BKW for over a year. There are a few things operators should be aware of. Ideally, the feedline should remain perpendicular to the feedpoint and high enough so that it doesn’t touch the ground. If this is not possible as in my case, you will not achieve a SWR lower than 2.5:1 across 40,20, 17, 12, and 10 meters. I can tune it to 80 meters, but 10 meters goes up proportionally. The antenna also becomes easily “unbalanced” if placed close to metal or in rain or snow resulting in wild swings in SWR. This condition allegedly can be improved by using 1 twist in the 450 ohm window line per 4 feet. I did connect and is recommended to use a 1:1 choke balun between the ladder like and coax to prevent common mode current in your equipment. There are a few vendors who recommend 52’ to 70’ of coax to get an acceptable match. All this does is attenuate RF and reduces effective radiated power. Use the shortest coax possible with something like RG-213, LMR400, LMR240, or RG-8x for very short runs.

@Linas_LY2H 7 месяцев назад

Thanks for sharing your practical experience, certainly useful for many ! 73! Linas LY2H

@DK5ONV 8 месяцев назад

I love ZS6BKW...my first home made Version was with a 300 Ω TV Line Feeder. Worked great for me as she supposed to for over 4 Years. 3 Month ago I built my 2nd Version of ZS6BKW this time with CQ-553 Wiremen 450 Ω Feedline. I left the Feedline at 12,35m to make sure it's long enough in case I need to shorten it. Havren't worked with my new ZS6BKW yet but it's on my soon To Do List. Tnx for Your great Video Linas, keep up the good Work. 73 de Your Friend Günter 💯🙋‍♂

@Linas_LY2H 8 месяцев назад

Thanks Guenter, and good luck with your new ZS6BKW! 73! Linas LY2H

@Davejazz 8 месяцев назад

Like World War 2, mose Code is getting contacts to the residents in France 🇫🇷 😊. Good job

@fotografm 8 месяцев назад

Excellent video. I really appreciate your clear and professional approach ! I need to find out more about the balun you used at the end.

@Linas_LY2H 8 месяцев назад

Hello, thanks for watching! The balun I used is the simplest form of the 1:1 balun :), it is wound on a FT-240-61 material ferrite toroid and consists of 16 turns of the RG-58 coax cable. The number of turns not critical, more, the better, 16-17 being just the number of turns which fits on this core. The method of winding doesn’t matter either, there is no electrical reason , for instance, to wind the turns in a “cross-over” way (when direction of winding is changed in the middle, and the end of the winding ends up on the opposite side of the toroid than the beginning). Simple 16 turns works just as fine as 2X8 in “cross-over”. So, one end of such a transformer is terminated then to the PL-259 or BNC connector and goes to the radio/ATU, the other end (comprised of the central contact and the shield) is connected (by whatever means you know, banana-plug, etc) to the windows-line cable (doesn’t matter, which goes to central contact and which to the shield of the coax cable). HTH, GL! 73! Linas LY2H

@fotografm 8 месяцев назад

@@Linas_LY2H Thank you for your informative reply, Linas ! Will give it a go.

@fotografm 8 месяцев назад

@@Linas_LY2H By the way, where is a reliable place to buy such ferrite materials in UK or Germany ? Buying the chinese stuff on Amazon seems like a bit of a lottery.

@Linas_LY2H 8 месяцев назад

@@fotografm good question! The best place, for me, in Germany is the Friedrichshafen Ham Radio Messe :), also, smaller ham radio events. Big Ham Radio dealers like Wimo usually also have some toroids to offer, others who make/sell antennas also should have toroids. In the UK, I remeber ordering toroids, among many other good things, at Sotabeams. The other time, I found some toroids at Farnell, big international components company. Local branch was pretty quick. My generall approach is to buy from well known electronics companies, or from companies who are in Ham Radio business anyway. I'm not saying there all fakes around on e-bay or Amazon, not at all, just it's just a bit of a lottery :), you need to choose and evaluate carefully the seller, at he extent it's possible. HTH, 73! Linas LY2H

@fotografm 7 месяцев назад

@@Linas_LY2H Many thanks, Linas for your detailed answer ! I was at Friedrichshafen this year for the first time and was amazed at the quantity of interesting items available in the halls of private traders. I will definitely go again ! It was even bigger than the hamfest in UK last year (which was unfortunately cancelled this year). 73 de Simon G4EYR/DL1EYR

@alainbibi0047 Месяц назад

Hey the coolest way to go in nature. Don't forget to put WD40 on the bicycle chain ? (ZS6BKW Antenna Review: My Review After 1000 QSOs K0LWC)_73👍

@45auto 8 месяцев назад

I do not have a tuner at all. I was hoping for more than 40m and 20m but we all want a simple antenna that gets every band under the sun.

@Linas_LY2H 8 месяцев назад

Hello, my version of the ZS6BKW works without a tuner ( but with 1:1 balun, it's in the second part of the video) on 40, 20, 17 ( on the limits) and 12m bands, so , 4 bands, actually :) Reports of other experimenters include 1 or 2 bands more , like 6m which I haven't even tried this time ( no 6m in KX2 :)). More scrupulous pruning, different configurations might improve the result even more. I like this design for its brilliant idea and big room for experimenting, and an excellent efficiency, that's what I want. But there is hundreds of other nice antennas which are multiband and need no tuner. One of my favorites- a linked dipole. You can have a full, real, extremely effective dipole on each band you want! If only your situation allows you to lowering the antenna down each time you change a band. In the field operation it's not a big deal. Also, there are antennas, loaded with resistors and , thus, providing a 1:1 SWR accross the entire ham radio HF spectrum. The price for that- you loose up to 50% of radiated power, but you gain a rapid deployment and care-free operation on all bands with the rest 50% of power ( like still solid 50W of a 100W). It could be the most important thing if you need to provide an emcomm service and your task is a reliable and quick link between points A and B on the best band of that moment. So, the choice is great, and it yours! GL! 73! Linas LY2H

@KG5IF 8 месяцев назад

Linas, I'm new to your youtube channel and enjoyed this video very much. Looks like a antenna that will work on many bands without a tuner. I usually run a doublet in the field and at home fed with a balanced line. Of course I need a tuner. What's your thoughts on efficiency between this antenna and a doublet? Thanks Rich KG5IF

@Linas_LY2H 8 месяцев назад

Hello Rich! Thank you so much, I'm glad you find something useful for you on my channel! I was not comparing yet my doublet ( 2X13m with 10m feedline) with the 'BKW in A/B test. General impression, the BKW works better on QRP on the bands where it needs no tuner, it looks like I'm getting better reports compare to what I recall from operating the doublet in simillar field deployment. Actually, both are low-loss due to symmetrical feedlines. The full-dipole size doublet would probably work better on 80m band, which is understandable, as BKW is much shorter. If operating with tuner, much depends on the tuner. My random length doublet does not tunes so nicely with a non-symmetricall ATU , as BKW does. It could be that the feedline acting as a transmission line transformer, tolerates better all this "balanced-unbalanced" thing. So, thanks for a good question, and let's keep on experimenting! 73! Linas LY2H

@KG5IF 8 месяцев назад

Linas, Thanks for the time writing your reply. I'm going to try the ZS6BKW based upon your experience. I do have the 10m fiberglass mask which I got from Vibroplex in my country and it's gone with me on several outings.

@Linas_LY2H 8 месяцев назад

@@KG5IF Cool! I’d love to hear your experience with this antenna! Good Luck! 73 Linas LY2H

@alexjh47 3 месяца назад

Very interested to know how you chose to cut the ladder line vs shorten the wire ends. Is there a way to observe that on the nanoVNA?

@Inkling777 8 месяцев назад

Is there a shorter version tuned from 20 and up? With the higher bands become more active, something shorter for those of us with limited space.

@Linas_LY2H 8 месяцев назад

Hello! It's already short an antenna, only some 27m overal length! :) And it works extremely well on higher bands. I've heard nothing about even shorter version, but I've red an article by the author of the ZS6BKW antenna Brian Austin (UK callsign G0GSF) where he describes the updated version of his antenna with the dipole legs bent for 90 degrees or so, and thus making the overal length of horizontal part almost twice as compact and the hanging ends only need some 7m hight. Accordingly to Brian, there is no feasible difference in performance compare to the full size. I don't have the link at hand now, but simple search should find it. Actually, I think, any form of bending or zig-zaging of this antenna would make no harm and would allow to fit even in a postage stamp property keeping, at the same time the necessary overal lengths of wires and feeder line. GL! 73! Linas LY2H