Baluns & tower project
 

Any advantage to having a B&W balun on a yagi vs "6 coils of feedline?"

Reason I'm asking is that the B&W 5K I happen to have specifies "SWR
less than 3:1". I know over almost any and every one of the five bands
my new beam covers (10, 12, 15, 17 & 20M), it'll be higher than that at
many points.

I'm putting up a 7 element full size Mosley Pro 57B I got from W5KDG in
Spring, TX a few months ago. What a job!

It's going on a 50' Glen Martin HD aluminum "Hazer" tower. The hazer
includes the Yaseu 1000 rotator and 8' mast for antennas, and cranks up
from ground level. I also have a Cushcraft (6M, 2M & 440) beam at the
top of the mast. (Mast reaching above the tower is about 4'). The Mosley
will be 5-6" above the top of the tower to clear when turning. Probably
have some interaction with the tower and guys being so close? Three 3/8"
stainless steel guys are fastened at the very top of the tower and
broken up with insulators. I figure the height will probably be the
biggest factor for stronger signals.

I'm now in the process of running five cables: 4 of RG/213 coax, plus
one for the rotator, down a "messenger line" (also 3/8" stainless cable)
from the hazer and into my shack. The coax lines are for the UHF, VHF
and HF beams, plus an Alpha Delta DX-A: 1/4 wave slopers for 160, 80 &
40M. FWIW: 50' of coax X 4 is pretty heavy!

For anyone's info: this is my "retirement project." Been licensed since
1957 while in high school, shortly after Sputnik was launched, but was
busy raising a family, and never had the space for antennas like this.
Also most neighbors here are horses which never complain. Hi!

Marv
W5MTV

Baluns & tower project
 

"MTV" wrote in message
...
Any advantage to having a B&W balun on a yagi vs "6 coils of feedline?"

coiled feedline chokes are not as consistent over a wide frequency range as
ferrite chokes. i don't know what is in the b&w balun, do you??


Reason I'm asking is that the B&W 5K I happen to have specifies "SWR less
than 3:1". I know over almost any and every one of the five bands my new
beam covers (10, 12, 15, 17 & 20M), it'll be higher than that at many
points.

i would expect a pro 57b to be well less than 3:1 across those bands..

Baluns & tower project
 

Dave wrote:
Reason I'm asking is that the B&W 5K I happen to have specifies "SWR
less than 3:1". I know over almost any and every one of the five bands
my new beam covers (10, 12, 15, 17 & 20M), it'll be higher than that
at many points.

i would expect a pro 57b to be well less than 3:1 across those bands..

I would expect the 3:1 SWR limit is at the rated power.
Reduce the power level and the balun will survive an
SWR higher than 3:1. If it is rated 3:1 at 5 kW, hams
shouldn't have a problem with a slightly higher SWR.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com