Jaybeam Q6-2 6 element quad for 2 metres

The place to talk about specific amateur radio equipment and all types of accessories, fixes, repairs and modification.
Post Reply
qrz45
Regular
Regular
Posts: 19
Joined: 13 Dec 2014, 21:26
Call Sign: 26KR102

Jaybeam Q6-2 6 element quad for 2 metres

Post by qrz45 » 02 May 2018, 07:54

Hello everybody. I would like to ask if anybody has any info on this antenna.

What is the gain of this antenna? I have read that it is 10.9dbd . But I have also seen a simulated diagram which is in German, that gives a figure of 9.26dbd.
I have 2 of these antennae and so am trying to get a rough idea what the effective vertical stacking distance is likely to be.

Also what is the feedpoint Z of this antenna? This I can find out myself but I thought I would ask first.

I have read mixed comments on this antenna regarding poor f/b ratio. So I am fully aware that there may be better antenna systems to choose from. However seen as they cost me very little in comparison, I would like to have a play for 2 metre ssb work mainly Sporadic e and Tropo.

Any info that you can give would be very much appreciated. Even if you have had experience using this antenna please tell me. I am interested to know.

Many thanks

Regards

Lee

qrz45
Regular
Regular
Posts: 19
Joined: 13 Dec 2014, 21:26
Call Sign: 26KR102

Re: Jaybeam Q6-2 6 element quad for 2 metres

Post by qrz45 » 02 May 2018, 10:07

I have since managed to find some figures for -3db measurements for E and H plane beam widths . From this I get figures of between 2.71 and 2.85 metres according to 57÷E or H.

Please comment if you have any other input regarding this.

paulears
Radio Addict
Radio Addict
Posts: 688
Joined: 10 Jun 2007, 22:41
Call Sign: G4RMT
Location: North East Suffolk
Contact:

Re: Jaybeam Q6-2 6 element quad for 2 metres

Post by paulears » 02 May 2018, 14:02

When I first got licence in 1980, I had two stacked tonna antennas, and my friend who did the RAE with me did the quad route. The practical difference was really that the quads did allow signals off the back of the beam to be heard, and useful, while my yagis had a pretty deep null at the rear.

We did a contest from the top of a 200ft grain silo - working into Holland, Belgium and Germany. The two yagis and four 4 quads (although we had 2 x 4 elements and 2 x 6 elements, through a 4 way power splitter, and they were really good - found an old picture. Looking back I've no idea how the radiation patterns of different types of antenna combined properly, but they did!
You do not have the required permissions to view the files attached to this post.

qrz45
Regular
Regular
Posts: 19
Joined: 13 Dec 2014, 21:26
Call Sign: 26KR102

Re: Jaybeam Q6-2 6 element quad for 2 metres

Post by qrz45 » 02 May 2018, 14:42

Interesting. Thanks for the pic and your comments. Not sure how that would work either as it goes against general stacking principles and theory. Yes I have read that the F/B ratio is poor on the quad. But it can improve by stacking which reduces the side lobes and increases the size of the main forward lobe. It would be interesting to put the elements on a longer boom and play around with the spacing which could improve F/B.

However seen as 2 metres is very quiet these days then the issue of poor F/B isn't really a major concern these days.

I am going to start with the figures I have mentioned and see what happens.

Thanks again for your comment and great archive picture.

Regards

Lee

paulears
Radio Addict
Radio Addict
Posts: 688
Joined: 10 Jun 2007, 22:41
Call Sign: G4RMT
Location: North East Suffolk
Contact:

Re: Jaybeam Q6-2 6 element quad for 2 metres

Post by paulears » 03 May 2018, 07:24

Sorry - just re-read. 2.7m as in vertical spacing between them? That seem extremely excessive. People used to stack and bay at quite smaller distances than that. The university of Surrey used 4 stacks of 16 element tonnas and they were no more than a metre apart as I helped cable them up many moons ago. No idea what formula they used, but spacing was not huge and these were mounted on two rotators for pan and tilt.

qrz45
Regular
Regular
Posts: 19
Joined: 13 Dec 2014, 21:26
Call Sign: 26KR102

Re: Jaybeam Q6-2 6 element quad for 2 metres

Post by qrz45 » 05 May 2018, 11:44

This just helps us to understand how techniques have improved. Check out M2 antennas and see what their recommended stacking distances are. The distances become greater as gain increases.

The formula 57÷ -3db(e or h) seems to be something to work from. However like always it has to be tested out.

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests