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Old May 30th 06, 05:39 AM posted to rec.radio.amateur.antenna
Sal M. Onella
 
Posts: n/a
Default Interlacing 2 meter and 70 cm beams


"VK3XL" wrote in message
...

Hi all, I am currently building a new 2 meter beam for SSB. I am using
the DL6WU design on a 6 meter boom. While working on the antenna last
night a thought struck me "why not interlace a 70 cm beam on the same
boom"?
so here is the question, does any one have any data on interaced beams
in particular the degredation of performance of the equivelent monoband
yagis.
There are a number of reasons that this interlaced beam idea is
appealing to me (mostly mechanical) but I am not sure how badly the
gain may be effected. Does anyone have real data on the issue?
many thanks
Mike
VK3XL


Some help: I saw one for sale at HRO a few years ago. Might have been this
one:

http://www.eham.net/reviews/detail/3297

Note also that many VHF TV antennas are this way; the low-band elements for
55 - 88 MHz share the boom with the high band elements for 172 - 216 MHz.

These two bands are approximately in a 1 : 3 ratio, as are 2M & 70cm.