2M 70cm 3x5 Dual Band Yagi

VK3YNV

Administrator
Staff member
I liked the one that Hayden VK7HH posted, so after a bit of searching on line and modelling a few different ones using EZNEC, I found one I liked and modified it.
I think the original might have been DW1ZWS. This is not going to be the final design, this is just to try out the construction methods, and see how accurate the modelling is. If it all works out I'll be doing another version. I'd like to tweak it to get better VSWR on 70cm.

The feed is direct coax with a pawsey stub balun.
The driven element is mounted on aluminium angle plates with hydraulic pipe clamps and a machine teflon spacer in the center.


Wombat3x5_2M_VSWR.png

Wombat3x5_70cm_VSWR.png

Here is the wires list.

EZNEC Pro/2+ ver. 7.0

Wombat3x5 22/06/2022 9:25:49 PM

--------------- WIRES ---------------

No. End 1 Coord. (mm) End 2 Coord. (mm) Dia (mm) Segs Insulation Wire Loss
Conn. X Y Z Conn. X Y Z Diel C Thk(mm) Loss Tan Cond(S/m) Perm
1 -524, 250, 0 524, 250, 0 10 31 1 0 0 0 1
2 -168, 298, 0 168, 298, 0 10 29 1 0 0 0 1
3 -464, 557, 0 464, 557, 0 10 27 1 0 0 0 1
4 -159, 587, 0 159, 587, 0 10 27 1 0 0 0 1
5 -149, 693, 0 149, 693, 0 10 25 1 0 0 0 1
6 -145, 826, 0 145, 826, 0 10 25 1 0 0 0 1
7 -139, 999, 0 139, 999, 0 10 25 1 0 0 0 1
8 -374, 1058, 0 374, 1058, 0 10 25 1 0 0 0 1

The ez files are in the attached zip file.



IMG_4675.JPG
IMG_4676.JPG


IMG_4677.JPG
IMG_4682.JPG
 

Attachments

VK3YNV

Administrator
Staff member
A few people asked at the meeting where I got the pipe clamps. I got them from here. I got the ones to suit 10mm tubing.


Price seems to fluctuate, so might be worth searching aliexpress to see if there is a better deal.

This one seems cheaper, but you don't get free shipping

 
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