Just follow the suggestions on the web page that was suggested and you'll be fine.
But I am curious as to where did you find the 1.25" fiberglass riod?
Joe
MM wrote:
Thanks for all of the good information.
I am going to rebuild my Sat array this spring (its time for a routine overhaul). I have a M2 436CP42UG and the M2 CP22 at opposite ends of a 12’ (1.25”) solid fiberglass pole. I am converting over to a 1.5” sold 14-foot fiberglass pole to give me better clearance for other antennas on the tower. Kenpro 5500 AZ/EL
I never liked hanging the coax off the back since is throws off the balance. When you slide the U-clamps Backward on the M2 boom to compensate for the coax weight on the back, you end up with the clamps on Thinner section of the Boom.
Based on the theories, if I follow the coax routing and avoid the half or full wave points I may be able to run the coax down the boom?
Would this work on the 70 cm too?
Thanks Miles
--- On Thu, 4/23/09, Jim Jerzycke kq6ea@pacbell.net wrote:
From: Jim Jerzycke kq6ea@pacbell.net Subject: [amsat-bb] Re: Cross Boom To: "Jeff Yanko" wb3jfs@cox.net, "Joe" nss@mwt.net, "Billy Simpkins" bsimpkins31@dishmail.net, "Edward Cole" kl7uw@acsalaska.net Cc: amsat-bb@amsat.org Date: Thursday, April 23, 2009, 1:41 AM It's here on Howard's site: http://www.g6lvb.com/fibermetalboom.htm
--- On Wed, 4/22/09, Edward Cole kl7uw@acsalaska.net wrote:
From: Edward Cole kl7uw@acsalaska.net Subject: Re: [amsat-bb] Re: Cross Boom To: "Jeff Yanko" wb3jfs@cox.net,
kq6ea@pacbell.net, "Joe" nss@mwt.net, "Billy Simpkins" bsimpkins31@dishmail.net
Cc: amsat-bb@amsat.org Date: Wednesday, April 22, 2009, 10:39 PM The coax shield coming off the antenna boom at a right
angle
looks like another parasitic element being added to the
antenna
causing severe distortion of the antenna pattern. But if one installs the antenna in the X configuration and attach the cross
boom in
a location away from any of the elements one can tightly
run
the coax across the metallic cross boom with little effect.
This
was tested by WA5VJB and is a published article.
I have my M2 436CP42UG mounted in this fashion and it preforms well.
73, Ed - KL7UW maybe someone else can point to the link to that
article.
At 11:41 AM 4/22/2009, Jeff Yanko wrote:
OK, I see where this is coming into play. So
it's
possible that the coax
shield could react to the feedpoint system and
pattern.
Now this raises a
question. If this is the case, has anybody tried
a
broadband choke balun to
limit this potential problem? If you think about
it,
the bigger issue with
coax effecting the radiation pattern is improper
decoupling of the fed
point. If the outside shield is hot with RF it
will
radiated and effect the
pattern big time. If the coax is properly
decoupled at
the fed point the
outside shield will ideally have zero rf current
on it
and ideally have no
impact on the pattern.
Thoughts?
73,
Jeff WB3JFS
----- Original Message ----- From: "Jim Jerzycke"
To: "Joe" nss@mwt.net;
"Billy
Simpkins" bsimpkins31@dishmail.net;
"Jeff
Yanko" wb3jfs@cox.net Cc: amsat-bb@amsat.org Sent: Wednesday, April 22, 2009 11:09 AM Subject: Re: [amsat-bb] Re: Cross Boom
Because the shield of the coax
"looks"
like a piece of pipe, and has the
same effect on the antenna pattern that
you're trying to eliminate by
going to a non-metallic cross-boom. Jim KQ6EA
--- On Wed, 4/22/09, Jeff Yanko
wb3jfs@cox.net wrote:
From: Jeff Yanko wb3jfs@cox.net Subject: [amsat-bb] Re: Cross Boom To: "Joe" nss@mwt.net,
"Billy Simpkins"
Cc: amsat-bb@amsat.org Date: Wednesday, April 22, 2009, 10:55
AM
Hi all, I found this line confusing....
"But then if you go insulated
then do
not run the
feedline along it either or you just defeated the purpose of the
insulated
boom."
My question is if you run the coax along
an
insulated
crossboom, ie. fiberglass, how could that affect the
coupling of the
transmission line when the object it is being attached to is "insulated"?
73,
Jeff WB3JFS
----- Original Message ----- From: "Joe"
To: "Billy Simpkins" bsimpkins31@dishmail.net Cc: amsat-bb@amsat.org Sent: Wednesday, April 22, 2009 7:06 AM Subject: [amsat-bb] Re: Cross Boom
>It all depends on how the elements > >
are
mounted.
>If at 45 to 90 degrees from the > >
crossarm, no propblem
and use anything,
>But if in the same plane then need > >
insulated
crossboom,
>But then if you go insulated then > >
do
not run the
feedline along it
>either or you just defeated the > >
purpose
of the
insulated boom.
>Billy Simpkins wrote: > > > >>Is a fiber glass or some other >> >>
non-conductive
material necessary for a
>>cross boom? What or the >> >>
advantages
and
disadvantages versus a metal one?
>>Thanks, >>Billy KF0CK >> >>
>>Sent via AMSAT-BB@amsat.org. >> >>
Opinions
expressed are
those of the author.
>>Not an AMSAT-NA member? Join now >> >>
to
support the
amateur satellite program!
>>Subscription settings: >> >>
http://amsat.org/mailman/listinfo/amsat-bb
>> >> >> >>
>Sent via AMSAT-BB@amsat.org. > >
Opinions
expressed are
those of the author.
>Not an AMSAT-NA member? Join now to > >
support the
amateur satellite program!
>Subscription settings: > >
http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions
expressed are those
of the author. Not an AMSAT-NA member? Join now to
support
the amateur
satellite program! Subscription settings:
http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed
are
those of the author.
Not an AMSAT-NA member? Join now to support the
amateur
satellite program!
Subscription settings:
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb