Parasitic lindenblad

[VK2FAK]

Hi all....

Wonder if anyone has built one of these.....feed seems a lot simpler than the original , even though this antenna is not strictly a Lindenblab...

[VK3XL]

I presume this is the design you are referring to
http://ww2.amsat.org/wordpress/wp-conte ... aLindy.pdf

Ive not built one, but it looks like an interesting idea.

[VK2FAK]

Hi all....

Yes one feed point and not having to feed all the elements...is very interesting idea...its been around for a while..

[VK5EI]

Hi John, I made several contacts with alan, vk6tdf on the ssb satellite birds and he was using a similar antenna and he was happy about it. What is you plan with this antenna ??

[VK2FAK]

Hi all...

Just for the moment I am looking for something that I can grab satellite telemetry with....as this antenna is Circular Polarized and has some reasonable gain, compared to other antenna's of this type...I was looking at making one...have bits and pieces here...so should not have to buy much if I give it a try....some parts look like a pain to make or find....the little hub section mainly...

[VK5EI]

Should be ok, make sure the coax feed is good quality and short length to radio.

A 70cm Helix design that is being used at Southhampton Uni, England, on their sdr radio is working well. More info at http://g8jnj.webs.com/currentprojects.htm

[VK2FAK]

HI all....

Interesting idea and design....have not seen the helix used like that before.....and yes seems to be working ok for them.

[VK2FAK]

Hi all....

Have made one of these now....and run one through NEC2

The swr is good....not quite as broad as I thought, but it good for the use suggested for the antenna..have not tested it for circular polarization at this time, but on air testing...seems to show no fading ...Had to make it with 6mm ali rod...so with shortening length ideas from Bob zl1rs....its worked out fine..

The measured swr goes from 433.0 1:1.5 to 439.5 1:1.3 436.5 1:1.05 These measurements apply to my setup and to be taken with a small grain of salt...
I tried an end cap on the top of the Vertical...it did not change the min swr much...but the outer values rose up..2 points of so....so used a plug type to go inside and not outside the element....this showed no changes to the original values..

the pattern looks like this....