[Antennas] antenna question

2003年12月13日 12:12:48 -0600

>What happens, gain wise, to a signal if I use my 
>12/17M 3 el cushcraft beam on 15M?

Bob,
Perhaps the reason is the wording of your query ...
"Gain wise"? As in does the 12/17m 3L yagi have a 
similar amount of GAIN due it's design on 15m? 
NO ... at best ... it will function as a dipole that you can 
rotate, with some possible skewing ... but GAIN as in
a pattern with F/B and F/S like the yagi was designed
for on 12/17m ... NO
>My rigs auto tuner flattens the SWR, 

Wonderful ... but has NOTHING to do with gain. Example?
My dummy loads here for each rig show a 1:1 SWR, but
they don't radiate worth a hoot. B-)
>How would that sig compare to if I just used a regular 3 el 
>15M beam. How much am I losing? Is it worth getting a 3 3l
>15 M beam, or should I just use the 3 el 12/17?

See above ... if you operate a lot on 15m, and really want as
good a signal as possible, then I would suggest the 3L 15m
yagi ... or going to another multiple band yagi, that includes
all the bands that you operate on there. If you only operate on
15m a small amount of your time ... and you can "work what
you can hear" with reasonable success, then run what you have.
BTW, if you ADD the 3L 15m to the same mast as the present
12/17m ... you may have some interaction between the 2 yagis.
Just another point to ponder there
Hopefully the above will answers you questions, if not please
ask for any needed clarification.
Happy Holidays to All ..
73 Billy AA4NU