CJU Antenna

[JohnUK]

Could anybody give me some details on the CJU antenna.
How much gain in dbd does it have.
Is the gain of the antenna achieved by the dimensions of the radiator or the spacings of the elements.
Is it possible to add a director to it.
If the radiating element is used without the reflector and fed with a balun,will I still get some gain.
I have spent 6-9 months looking on various sites,but as yet,I have been unable to find the gain figures.

Regards,John

 

[prcguy]

I don't recall seeing a full wave loop with a reflector on one edge end before but I would estimate the gain to be slightly more than a 2 element Yagi at best. No reason why you can't add directors for more gain like a conventional Yagi.

 

[JohnUK]

PrcGuy.
Thanks for the reply,I have delayed in answering to allow any more members to reply,but nothing.
The CJU is used mainly for satellite coms,for example ao51.There is a 2 band version called the IOIO.
The CJU is supposed to give the gain of a 4 element beam.

Regards,John

 

[kb2vxa]

"Is it possible to add a director to it."
Yeah it's doable but the bigger it gets the more it gets out of hand. It's compact design is for hand held operation and can easily be connected directly to an HT just like the common rubber ducky. Using a speaker-mic it's just point and shoot.

 

[JohnUK]

Warren.
Thanks for the reply and photograph,I like the way that you have enclosed the UHF section within the VHF section.Do you find that there is any interaction between the elements,as they are in the same polarisation.
How would you rate the antenna in terms of dbd gain.Nowhere can I find any reference to its gain,only that it is comparable to a 4 element beam.
I am only interested in the UHF side of the antenna,as I want to rescale it to cover 446mhz,that is the same as your FRS.
If you have a spare moment,visit our web site,

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Regards from the UK,John.