Feeding and Matching my Beam

Thanks for the reply Henry.

I was thinking this thread was trending the discussing toward and idea for why a yagi antenna with a gamma was a bad idea and that the beta match was much better choice.

In this case I was remembering your bent driven element 11-4 F antenna and I thought it was pretty good idea to consider. I goofed up and did not explore the CMC issues fully, and Shockwave's comments brought light to my error.

I'm sorry I posted the misleading information above. That said however, I think maybe some folks may have benefited with some better understanding for this issue on CMC, as a result of my mess up and Shockwave coming to my rescue.

 

Is your email still working ?
Ill send you some "f" yagi designs.
(F = folded dipole)
(V= v shape bent radiator)
For your comparisment.
Ill send the SWR plots of the "F" version to as NEC2 doesnt like closed spaced wires that much.

Tnx fr ur fast reply.
73. H

 

Yes Henry, but I'll PM you the address to confirm.

 

Thank u for the confirmation.

The pg0dxhenry (at) gmail account is still used here.
Hoping to see it tomorrow morning. (2200 local now...dog allready calls... and need early rise for greyline dx hi)

Enjoy the weekend, kind regards Henry.

 

Henry, I just remembered what I did. I was thinking about the issue in the thread. I had a recollection that maybe you once presented this idea as a model on your Website. I went there and saw the 11-4 F. I could not see the antenna well but the description sounded about right, so I looked up on my list of Eznec models for 11-4F. I found nothing, so I took a Maco 104-C horizontal model I had made and I applied the isolated direct feed idea with an angled back driven element toward the reflector.

The model worked out nicely for the match and I got a perfect Average Gain = 1. I realized the boom was about 30+ inches longer than your 11-4 F model and I intended to fix that. However a day or two later when I got back to this idea...I forgot to fix the model and then I got lazy and didn't want to take the time for the fix.

It wasn't so much the antenna I was thinking about...it was the idea of another method to direct feed a yagi without a matching device, and I wanted to give you credit for the idea.

No excuses, I just got lazy and goofed it all up.

 

couple files have been send Marconi.
Let me know if i can help in any other way...im not much on forum.

Your "mind set" to "direct fed" is perfect !....

If you have a "beam" and you like it on computer, just play with only the radiator and 1st director in order to make it resonant.
I often did that by inserting them in 4NEC2 and just let the optimizer do the work.

Bringing the radiator closer to the reflector will lower the impedance and improve gain (as there is more boom in front of the radiator remaining).

A director close to the radiator can be used to "balance" things out. Like a 4el on a 6 meter boom can do the same in gain as a 5el on that same boom....but that 5el (an extra director just in front of the radiator) will bring up the impedance and make it wide band (stable) and usable for QRO in all situations. "us" old guys would say....that 4el on a 6 meter boom is the "long john" (name comes from Hygain) and that 5el is an "OWA".

Though "long john" sure sounds nice.....and certainly was "best" and there is absolutly nothing wrong with it, fine antenna !
These days it migth be better to add an element for overall "stable" performance.
I would do that, but guess its a bit what the user wants hi.
If the user things its great, well its going to be hard to beat that thougth hi.

Kind regards,
H.

 

Henry, have you ever worked with an antenna similar to the one I posted? I never had such an idea.

 

U mean with a bend radiator ?
Yes, that is a well known concept.
although he doesnt really wants credit (I believe?) we all give credit to K6STI for having it made commenly known,

if send you a couple files of "V" yagi's too.
One of the early verions was known as the "jungle job" antenna (google it).
two versions, one with the reflector bend and one with the radiator.
Must have been in the 50s/60s when they first showed up.
Infact TV antennas have used that concept in the past too.

Overall...the impedance goes up, and again over a wide frequency remains stable. It more or less has the bennefits of the OWA and has the high gain of a traditional low impedance yagi. (best of both worlds hi).

If you are reffering to another idea ? please post it again tnx !

73 Henry

 

Yes Henry I was talking about a bend radiator designed antenna.

I'm still trying to figure out exactly how I got the idea for the bent radiator that I modeled.

My curiosity and the question I asked you above...is not important to our discussion. I'm not on some campaign for giving credit to anybody.

I was just trying to add another antenna design idea to this thread, and I knew it was not my idea.

 

Hi Marconi !

I was just "speaking out' what i knew about the bent radiator.
Im not on a capaign either...just providing information..

Well, where did you get it from ?
Maybe i have posted one of these antennas here in the past ?
I think i did, using a few MACO designs ?
I tried to search the forum, but seems V-yagi isnt "searchable" hi.
Maybe you saw it at cb-antennas.com ?
http://cb-antennas.com/?page_id=461 or at the other site you mentioned...

Perhaps of use:
...since a while they are more commenly used in the HAM world.
People see the bennefit, some good designers like:
DG7YBN has them on his site, and i believe DK7ZB G4CQM as well. (google them for the websites) Perhaps there is where u saw it ?

They are sure fun to play with !
Im rather confident it is amongst the "top" of present modern yagi's.

Enjoy the sunday, Kind regards, H.

 

I understand.

When I thought about this idea and this thread, your model came to mind. So, I don't forget everything. I Googled your acronym "HPSD" and apparently got another of your Websites.

This is your Website where I saw this antenna.

I agree Henry. My problem is...sometimes I can't quite get my memory of more current happenings to working right.

Good to hear from you again.

 

Marconi , does my almighty Antenna God Have a Clone ( Henry ) also can't forget Mog . ? Can this forum get any better ?