DIY 3 element yagi

[Buffalo]

Hi guys. I slapped together a 3 element yagi knowing the very minimum of what I was doing.
Goal: something super light weight that I could put on top of my 11 guage telescopic flagpole
Construction materials:
Boom: aluminum painters pole
Hubs: 3/4” 4 way pvc fittings + 6-5” pieces of 3/4 pvc
Elements: cheap fiberglass telescopic fishing poles
Wire: 14AWG solid copper wire.

Right now it’s up about 26’ on the pole with no adjustment beyond the original cuts. It is direct feed with no matching network. Or Balun. As expected resonance is on the low side. Like 1.2/1 on 26.800 thru Channel 20 and swings up to 1.5/1 on 27.405. So it is completely usable as is. I don’t know if it was Mother Nature smiling on me but when I first got it up I made more contacts across the pond than I ever have in one day. With one station in Ireland comparing it to my Sirio 2016. Hard to quantify in actuality because of so many variables but I was pretty jazed. Needless to say.

Another reason for the goal of super light weight was so I could use an inexpensive rotor.

All that said I want to bring resonance higher up the band and don’t know exactly what to do. Do I just shorten the driven elements? All of them in proportion to my original cuts? Or something different like just the reflector and driven? I suspect an inch or two will be the end result but the copper wire is internal to the frame with only the tips exposed for now for tuning. So I will cut very small and be patient. Very easy up and down on that flag pole and my guess the antenna is maybe 6-7 lbs. any input appreciated!!!! Image taken it was very dark a couple of nights ago when I first pushed it up there.

 

[Cable Guy]

Imagine the waves you can catch with that Shakespeare rod array. Idk about the details but it sounds like you got it going on with that match and them dx contacts. I'd like to see the connections and build one too. I have a maco 3 and it looks like the elements are spaced a little closer between the driven and director elements than yours. Good job.

 

[sp5it]

What is F/B ratio?

 

[Buffalo]

What is F/B ratio?

I have no idea. The best I can say is there is a difference front to back. I’ll know better when I can turn it.

 

[Buffalo]

Imagine the waves you can catch with that Shakespeare rod array. Idk about the details but it sounds like you got it going on with that match and them dx contacts. I'd like to see the connections and build one too. I have a maco 3 and it looks like the elements are spaced a little closer between the driven and director elements than yours. Good job.

Yes I noticed that on the Maco 3 just today looking at a video. I was looking at a Sirio 3 element when I made that choice. Ref- driven if I remember on mine is 4’5”… driven to director 5’. Fee point is an SO239 bulkhead connector mounted in the pvc fitting W/ rubber gasket. Driven is isolated from boom others are not.

 

[Riverman]

Any detailed sketches or notes you can share that show all of the dimensions?

 

[Buffalo]

Any detailed sketches or notes you can share that show all of the dimensions?

Here is what I used only difference is the spacing between the director and the driven element I made 5’. 4’5” between reflector and driven element.

 

[Buffalo]

Just some notes I cut the wire as precisely as possible measuring from the center of the boom.
Don’t know if you can see it in this image but the 5” pieces of pvc that are glued in the hubs were heated and bent slightly upward to compensate for some of the sag I knew I would get from the poles. I did this with the antenna assembled and upside down and let gravity pull them downward as I heated the pvc. Not perfect but as close as I could get.
The solid copper wire was anything but straight so I straightened it using a vice and a drill. A process I found on the net that was pretty cool and worked well.

 

[Buffalo]

Imagine the waves you can catch with that Shakespeare rod array. Idk about the details but it sounds like you got it going on with that match and them dx contacts. I'd like to see the connections and build one too. I have a maco 3 and it looks like the elements are spaced a little closer between the driven and director elements than yours. Good job.

LOL forgive me i’m a little slow just got the joke!!!

 

[Buffalo]

Having a lot of fun here and learning a lot in the process. Tuning was not responding as expected so I decided to add a 1:1 Balun just to see what happened. Seems to have made tuning a breeze. Tuned it close 2.5 feet off the ground and nothing changed to my surprise when I put it up. Resonance is still around channel 1 according to my VNA. Easy enough to adjust it a little more.

 

[Buffalo]

Wish I had made it with flexible wire in which case it would be completely portable. Not so with the solid wire.

 

[Buffalo]

I ended up changing the spacing and lengthening the boom. 6’4” between the reflector and driven element and 4’1” between the DE and director. I was having issues with the match the higher I went up. The changes I made seemed to help with that. Correct me if I’m wrong but I think the match looks better on the VNA also… 1.2 on 1 and 40 and flat around 20. 38 is still 1.1… much easier to tune with a Balun. It’s definitely talking. I do realize even a poorly performing antenna can do some amazing things with the help of Mother Nature!!!!

 

[Buffalo]

Dropped the antenna due to high winds and the fact I have no guy wires on the flag pole. Decided to do a hair more tuning.. I’m actually finding my results a little difficult to believe. But I’m not complaining. Sweep from 26.805 to 27.555. VNA, MFJ, and radio meter all agree!!! Except
VNA reads a little wider banded.