144Mhz yagi designed for backpacking portable.

G1YBB

Member #381
New member
I've just finished a 9 element DK7ZB 144Mhz long yagi designed especially for backpacking portable.
Nearly all my operating is done portable but it used to be from drive on sites and the yagis on a roof rack. With LiFePo4 batteries and FT-817s around now I plan to operate from my favourite summit that I have always had my eye on.
So needing to pack a yagi down to carry really meant the elements coming off. Usual method of screwing elements on is slow and time consuming so I got the thinking cap on and the 3D CAD out and designed (mechanically) a way to achieve this simply and easily.

Finally finished now and glad to say I can fit the 9 elements in 90 seconds.

finished-DK7ZB-yagi.jpg


Video fitting the elements:
https://youtu.be/oUqktapm10g

Full description is here
http://g1ybb.uk/portable-9-element-144mhz-dk7zb-long-yagi/
 

G1YBB

Member #381
New member
Seems to work pretty good. Used it in the UKAC last week and looking at claimed scores 2 more UK squares that I should not have missed would have given me top spot in my section.
Very pleased with it
 

M0LMK

Member #2
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Staff member
Very good. I like your method of mounting the elements. Very quick and easy.

Great that you can supply the element mounting plates and I see the guy ring which also looks good. May have to add a few of them for my 12M pole!

Shame that company doesn't produce your HF wire dipole spools.
 
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G1YBB

Member #381
New member
Very good. I like your method of mounting the elements. Very quick and easy.

Great that you can supply the element mounting plates and I see the guy ring which also looks good. May have to add a few of them for my 12M pole!

I'm hoping to re-use the element plates for future projects. They would certainly be big enough for 28/50/70MHz yagis I reckon, if there are clips out there to suit the elements.
For the 10mm elements when not windy you probably don't need to snap the locking 'flap' closed. That does add a tiny bit more pressure on the elements. All in pleased how it turned out.

And the guy rings. The plastic is amazingly strong really. It's used in some medical application where they things go through the autoclave many times through their life. Quite easy to drill out the 20.5mm hole bigger with a step drill for bigger poles, or would file easily. I leave the rings and guys tied to them on the mast (the red bag in picture above contains the top two sets, bag is just for containment and protection for the guys) makes it pretty quick to deploy.
If you do get some be cool to see some pics of them in action.
(disclaimer-I make no money from any sales. My 'reward' is getting just what I want for my projects for free)
 

G1YBB

Member #381
New member
dug up some pics from the trial UKAC contest on the 5th.

The entire setup carried solo:



Setup


Sunset
 
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G1YBB

Member #381
New member
Shame that company doesn't produce your HF wire dipole spools.

Just spotted this edit.
Interesting comment, I expected to be in the minority not liking the kite style winders for the wire.
The wire spools are downloadable if you have a 3D printer, which is how mine were made. Injection moulding tooling for them would be a fairly expensive investment if take up was low.
 

M0LMK

Member #2
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Staff member
I don't have a 3D printer but would be happy to buy a couple of printed ones ;)
 

M0LMK

Member #2
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Staff member
Ordered some of your element holders Steve.

Now I just need to find somewhere local to pick up a 3M length of 20mm x 20mm box section....
 

G1YBB

Member #381
New member
Nice one on the plates.

I have a spreadsheet at work where I have compiled suppliers I have found. Not so easy to get metric in UK but there are some.
I can share what I have found tomorrow.
 
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M0LMK

Member #2
Full Member
Staff member
Not sure what design i'm going to build. I'm edging towards a 9 element LFA at the moment.
 

G1YBB

Member #381
New member
The LFA seems to be one of the popular 'newfangled' designs. (I'm still catching up from the DL6WU and DJ9BV era :) )

But I am really loving the performance of the DK7ZB. Seems to work amazingly well compared to others I have had.
 

2E0IEH

Member #498
New member
Very interesting. Guess i'm a bit late to the party ! Guess you had a few hours of use with this since you original post !
 

G1YBB

Member #381
New member
Very interesting. Guess i'm a bit late to the party ! Guess you had a few hours of use with this since you original post !

Hi Tim. Yes the yagi is serving me very well in contests. I have since followed it up with a 6 element on 6m and another 6 element on 4m.

But the 2m one is really doing the business for me. I won last year's backpackers series with it, and doing well this year, and also have won my section sessions in the UKACs so far this year with it. Highly recommended!
 

G1YBB

Member #381
New member
Not sure what design i'm going to build. I'm edging towards a 9 element LFA at the moment.

Well I never did come back to you did I!

Probably long since built yours but I got more 20mm box from metals4u.co.uk who do up to 6m lengths which is handy!
 

2E0IEH

Member #498
New member
Hi Tim. Yes the yagi is serving me very well in contests. I have since followed it up with a 6 element on 6m and another 6 element on 4m.

But the 2m one is really doing the business for me. I won last year's backpackers series with it, and doing well this year, and also have won my section sessions in the UKACs so far this year with it. Highly recommended!

Great to hear. Will listen out for you on the next 2m UKAC ! Regularly have myself & another member of local Hinckley Club operating /P but not as portable as you ! Keep up the good work !

Cheers

Tim
 

M0LMK

Member #2
Full Member
Staff member
Well I never did come back to you did I!

Probably long since built yours but I got more 20mm box from metals4u.co.uk who do up to 6m lengths which is handy!

Ha! We've all been a little busy!

That's where I ended up getting mine from. I'll pop some pictures up next time I have it out.
 
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