HAM Radio: 2M ZL Special 7 Element YAGI build, (Kitchen Projects)
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- Опубликовано: 14 июн 2020
- The construction of a shop purchased, ZL Special 7 element Yagi antenna for the HAM Radio 2M band. This no frills antenna boasts a 11.5 DBd Gain, is simple to build and works straight out of the box (once put together). Great bit of kit at a good price. Brilliant :)
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Cheers
Mike M0MSN
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Brings back happy memories of when without a morse certificate VHF and UHF bands were all we had. I came across the ZL at the same time as the Slim Jim, both highlighted in a publication called "Out of Thin Air". Title says it all. When Jaybeam and Cushcraft were the only popular antenna manufacturers around. The 'Ringo-ranger" collinear! How it all comes flooding back. Thanks for posting its a great aerial but do as Roly suggests - mine used to fill up with water. 73 de M0AZE Mike.
Nice detailed build Mike, along with adaptation of less than desirable components. Good to see little to no affect from the metal mast being behind the reflector. 73
Made my first 5 ele ZL in around 1985, a year after getting my ticket...courtesy of Fred Judd (G2BCX). Then my pal and I made Freds '2BCX' which was basically a 16 ele ZL..which he took all over Scotland on holiday on the roof of his landrover. We used trimmer caps for the SWR. Hope you sealed the end of the stub open to the weather.
I'm new in ham radio world, I started a few months ago but I loving this world and it's satisfying see building antennas
Nice build - and very nicely done video, sir! Thanks for sharing that.
"Fiendishly clever" huh :) Nice build Mike. I use a little bit of RTV around all the cable entry points to stop water from getting into your nicely soldered joints. Cheers.
Thanks for the upload; I appreciate your efforts!
That's a versatile antenna! I love the idea of being able to switch polarity so simply; just lovely.
I am having a 12m mast installed in 2 weeks; have an 11 element beam for 2m and a Diamond X6000 going up. Two feeds, but c'est la vie! 😊
Best,
John
Newly minted 2E0SVB
Thanks 👍
Nice looking installation. Well done Mike. I hope you get many years of service of what looks like a well designed antenna. 73 Joe
Thanks 👍
Great build like always. Keep up the great work and the fantastic videos.
Thanks,
I have a 5 element one which I bought back in about 1987 or so. Mine has a variable capacitor rather than a length of coax to match it.
Hey, another IC-706MKIIG user! I still have mine in service, bought it new when it first came out. Antenna looks intriguing! Interesting, running a second driven element 180 degrees out of phase from the first. Thanks for the vid!
Yes great radio. :)
Thanks for the video Mike. In all the years being into radio i've never dabbled with beam antennas on 2m. Maybe I should give it a go! 73, Matt, M0DQW
Great idea Matt, I can recommend these ZL's brilliant bit of kit.. ;)
Another informative video Mike.
It's great to see what others get up to and to see what I can only hope I can fit in my attic! 😂
Cheers Paul
I have a 5 element in my attic, I've had it since 1987 or so and moved house with me. 🙂
Ooo I do like a build. Well done Mike 👍🏻
Thanks Ian
nice one mike
Hi Mike- Very well explained vid for the Moonraker 7ZL! Yes, a pain the ass doing the connection box connecting and not recommended if you are tired ! Surprised they haven’t modified the design in all these years. I have used one extensively (along with 9 ele OWL, 11 Tonna etc) and it has its place in the collection - I do hilltop DX and Contesting from the middle of U.K. (IO93, sigs all directions) and it’s wide beamwidth with multiple ‘petals’ suits for maximising number of contacts ( but not necessarily overall furthest distance). Indeed in Feb this year I managed to exceed 200 contacts in a 150 minute contest for my first time ever. I got a ‘rally special’ price approx 10 yrs ago at £40 (vs £79 reg) so defo worth the purchase AND it conveniently sits fully assembled in large car boot or motorhome bunkbed so its an ‘easy up’ on rotator on cold or damp nights. That said, for longer period, ‘distance-based’ contests I tend to use a larger, sharper beam (in conjunction with horiz ZL and a vertical (sometimes combined via coax power splitter)) so I chose my antenna depending on the rules, the weather and my state of mind! I particularly enjoy a day out on 2m FM having rag chews vertically polarised. The ZL is a great all-rounder for that. Even flat-side, fixed position it will probably still give better geographically omni performance than a big-wheel with added advantage of its front gain too. One of my driven folded elements is getting a bit weak now and so if it finally became irreparable then I would probably get another. As a final point, like you I too added a couple of feet RF58 coax to the feed box (anything larger very difficult to fit) and then run Westflex back into motorhome shack. Hope my waffle is useful to others and thanks again for documenting its construction! 73 Nick, M1DDD
Cheers Nick. All good stuff.
@gm4dhj it wasn't the best Bond film, :)
Thanks for this Mike, the measurements will be really useful. It certainly works well and looks of good quality. I wonder how it is now, as it's a while since you made the video and built it?
Nice antenna Mike.
thanks
Mike, I must say I would have never guessed it would have worked, first crack out of the box !
Strange you had to modify the housings?
I particularly like the end mount design !
Congrats, from the U.S. !
Cheers, and '73
Thanks 👍
11.5 ISOTROPIC bananas 🍌. Not falling for that one again..
Lol
That’s one nice antenna Mike. Nicely done. 73
Cheers Tim
I have a similar commercially made one but I found the measurements/lengths etc somewhat different to rex judds original article.
Hi Mike hope you enjoy the new beam I had the 12 element when I passed still got it old qth was Derby quite high in derby antenna height about just above apex of roof using my tm751 25watts had many qso's in to Isle of White all the best Adi G7MUY Ingoldmells
Waiting for the rotator. :)
Good video and shows the ways round the laziness of the makers. Why didn't they provide better instructions and the extra bits you needed. I had to do a similar job with mine. Its very hard if using larger coax
Great build vid Mike as they all were, just back to backed all your lockdown antenna builds really like the non-split dipole you did for 6m not seen that design before.
I was just thinking " I need to ask for the dimensions of this yagi-uda" when in the true spirt of amateur radio you did just that - Awesome,thanks.
lovin the coil builds ,as that's what I'm doing at the moment.
What I would like to ask Mike is - I also have a IC706 mk2 and cant work out if i need a peripheral component to access CTCSS for repeaters, cant seem to spark them up even though iv'e put in the offset and tone frequency.
Anyway, Great Channel Mike. Job Done - Well Done.
Barnie M7PBX.
Thanks, may do a quick video on programming the 706.. :)
You are the hands on amateur radio stuff, very practical, must have a understanding wife as well lol MIKE M1KEY M0FCG
I purchased one of these cant get the swr down below 3 in any part of the band tried several changes and meters of coax trimming later still no good gave up on it for time being :(
Good video Mike. That antenna clearly has decent gain, would be good on 2M SSB. 73 Chris M0RSF
SSB : )
Thank you for this video sir. I have used ZL specials on and off on 20M for years (no directors) I wonder why you use such lossy coax on 2M?
cool content keep it up
Looks like the last (farthest from the driven) parasitic element is wider than the others? That's ass backwards from other Yagis such as my Arrow? Something to do with it being a loop with no reflector?
Bagus antena db besar👍👍
Thanks for that 😊 Do you think it’s light enough to use handheld?
Light yes but a bit big maybe???
Where do you get the poles from? Great informative video de M0ODZ
Local Aerial installation shop ( AJL Electronics - G6FGO)
I found the the solder tags on this antenna were way too small . Very difficult to connect rg213 to this antenna . Would have liked to see a pl259 connector pre installed for the money.
Yes I agree, but you can connect a short length of coax with an SO239 on it.
Nice antenna.
73 de
Aiden EI8HJB.
can you say what are diimensios of the boom (square)
yep, 2 x 2 x 178cm
Id be interested in where you bought it. Im in the need for a 2m high gain directional antenna and Im just starting out. thanks :)
A HRO or eBay
A great demo but where do you get them from? I'm in ZL. NZ
eBay
Hi Mike. I have the 12 element version that I bought secondhand. It looks brand new. I do have a problem though, very high SWR, in the region of 2.5:1 t0 3.0:1 I've tried everything, new coax (Ultraflex 7) redone the stub and carefully cut it, best SWR above is with no stub. Any ideas?
Try a different length of stub start long and cut it back to get best VSWR... good luck
hi Mile I am in Brasil.,and I am doing the your antenna.I would like to know if directors are connected to the boom or no.
Yes all directors are connected to the boom.. good luck
You forgot a link to the antenna for purchase
Local Aerial installation shop ( AJL Electronics - G6FGO) or local Radio shop
Another nice build (& a few more scratches on the kitchen work surface) Mike, good going 👍 What’s your plans for it, install at home or /P ?
Not sure yet
@gm4dhj Don't let my wife hear you say that......If I damage the worktop I will replace it, it is that simple.
Hi Mike .... My nearest repeater is about 50 miles away - this I can access with my home-brew three element beam. I would like to be able work into another 2M repeater about 100 miles away. In your opinion would a ZL special + rotor or a Diamond X 510 be most beneficial ? Thanks ☘️
Sorry there are to many unknowns, line of sight, height of the antenna to repeater, if both are in line of sight the ZL may do it.
@@mike-M0MSN Thanks for taking time to reply Mike ... I’m afraid neither repeaters are in direct line of sight but I’m near the coast on an elevated site Approx 400’ above sea level with clear take off in all directions ....
Hi Mike I also have a ZL special but it is a 12 element I’m not that impressed by it? I found the SWR to be 1.5 to 1 whether I have the stub or not. I fitted the stub and reduced it millimetre by millimetre and it made no difference and was better removed. Can you give me your thoughts on that? I have now added an amplifier also coax to make it fit, it now reads 1.7, 1.9 to1 can you give me your thoughts.
Regards M0uhf
I would do a re-build personally and increase the start point of the matching stub (make it longer).
@@mike-M0MSN Test each element for short to boom. Should be open.
I like the antenna, send it to Indonesia..🙂🙂
Its on eBay
@Mike-M0MSN Where can I find one of these? 73
Got mine from Moonraker via the internet
@@mike-M0MSN thank you, 73!
It brakes my heart to see one uses a pipe wrench to assemble nuts and bolts...
Sorry Mate, Its what I had... :(
@@mike-M0MSN No worries, I've a big heart...
Where you twisted that piece of ribbon cable.. the twist should have been made over it's exposed length on its way to the next element. Why? So the conductors maintain their spacing. It's a piece of balanced transmission line remember...
Dazzwidd I do not think it is that important as the antenna is working wonderfully....
@@mike-M0MSN Just giving you something to consider... It might have been even a little better in some way is the thought, as the fact is it was designed to use that impedance of balanced line to phase the two driven elements. Bringing them crossing together like that is not a good thing.
Anyway I remember reading the article about this antenna in the practical wireless magazine back in the 70's.
I was a teenager and had inherited a lot of radio/electronics magazines.
Some were very old. I had issues of The radio constructor from the late 1950's!
Dazzwidd I do enjoy reading and value your input, many thanks. 👍
@@mike-M0MSN Your playing around with some interesting antennas. I wish I had a yard at the moment to be able to put antennas outside.
Lately I have had to mess around indoors.
In the past 9 months I have made some interesting ones for inside.
For 27mhz I started out with a loop of 3.4m circumference which I was getting out on the DX with but then upgraded to 4.2m circumference... so basically a halo that was shortened. I had a capacitor at the top made from two copper tabs hanging down. The matching was a copper strap gamma. I was getting a dead flat SWR at resonance. Recently I trailed taking the capacitor off the loop and adding two aluminum stubs, one going up and one down (both 1m long) and it resonated again with low SWR, but giving circular polarization- I REALLY want to get this outside! I also have made several fm broadcasting band aerials such as the slim jim and a ring and stub antenna that was adapted from an fm broadcast band halo, which was the inspiration to try it on 27mhz. This hobby is all about experimental trial for learning as it's the most fun!
My girlfriend would go ballistic if I did “radio stuff” on the kitchen worktop...
Top banana in the kitchen
Oh yes
it is “meter” (like in Peter) and not the French word “metre“ !
Sorry Paul, its a French word and my wife told me to spell it that way.. LOL
@@mike-M0MSN Yep, it's metre. C'est vrai!
A meter is a thing with a needle on it which moves to tell you how many thingies it's measuring.
That would be the seven element ZL Special for 2 meters as developed by G2BCX and as featured in the Practical Wireless publication " Out of thin air " also featured is the 12 ele and 16 ele ZL special for 2 Meters . Kind regards Chris @ G4MXC