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
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
Indeed, my M Squared cross polarized Yagis need to be on a fiberglass boom. The coax from each of them heads straight back into the air and forms a loop down to the mast several feet below the elevation rotor. E mail me direct and I'll send you photos if you want. You'll be happier with a fiberglass boom. 73, Pete WA6WOA
--- On Wed, 4/22/09, Joe nss@mwt.net wrote: From: Joe nss@mwt.net Subject: [amsat-bb] Re: Cross Boom To: "Billy Simpkins" bsimpkins31@dishmail.net Cc: amsat-bb@amsat.org Date: Wednesday, April 22, 2009, 7:06 AM
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
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" nss@mwt.net 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
Because you now have a metal object (the coax) running along the fiberglass boom, and this WILL effect the radiation pattern of the antenna. and possible the match also.
Jeff Yanko wrote:
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" nss@mwt.net 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
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" bsimpkins31@dishmail.net 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" nss@mwt.net 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
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those of the author.
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Subscription settings:
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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" kq6ea@pacbell.net 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" bsimpkins31@dishmail.net 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" nss@mwt.net 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:
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No, That will not make any difference.
we are ONLY thinking of the metal in the near field of the antenna,, and how it effects the radiation pattern as well as impedance of the antenna.
Now add in feedline radiation and you just oopened up a whole new can of worms.
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" kq6ea@pacbell.net 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" bsimpkins31@dishmail.net 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" nss@mwt.net 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:
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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" kq6ea@pacbell.net 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" bsimpkins31@dishmail.net 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" nss@mwt.net 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:
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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
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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" bsimpkins31@dishmail.net
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" nss@mwt.net 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:
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
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Subscription settings:
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:
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Sent via AMSAT-BB@amsat.org. Opinions
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Sent via AMSAT-BB@amsat.org. Opinions expressed
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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
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satellite program! Subscription settings:
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Sent via AMSAT-BB@amsat.org. Opinions expressed
are
those of the author.
Not an AMSAT-NA member? Join now to support the
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Fiberglass solid.
I forgot who actually makes the rods, but i found a local deal that can get it in 20 foot sections. I bought two 20 foot rods and sold off the extra sections. The cost is aprox $16.00 a foot.
the nice thing about solid is you do not need to worry about breaking or crushing it.
Structural Shapes Rod Class: thermocur rod Major Material: Fiberglass Minor Material: 1.5" solid rod Outside Dimension: 1.50 Color: MILKY green Resin Name: green Length (Span for Grating): 240.000
Rick McCabe Customer Service Team Leader McNichols Company 45 Power Rd Westford, MA 01886-4111 978-692-4141 ext 227 (phone) | 978-692-0044 (fax) rick.mccabe@mcnichols.com www.mcnichols.com
--- On Thu, 4/23/09, Joe nss@mwt.net wrote:
From: Joe nss@mwt.net Subject: Re: [amsat-bb] Re: Cross Boom To: ka1rrw@yahoo.com Cc: "Jeff Yanko" wb3jfs@cox.net, "Billy Simpkins" bsimpkins31@dishmail.net, "Edward Cole" kl7uw@acsalaska.net, kq6ea@pacbell.net, amsat-bb@amsat.org Date: Thursday, April 23, 2009, 6:43 PM 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"
kq6ea@pacbell.net, "Joe"
"Billy Simpkins"
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"
"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
> Subject: [amsat-bb] Re: Cross Boom > To: "Joe"
>
"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
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of the author. Not an AMSAT-NA member? Join now to support the
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Max-Gain Systems sells it. http://www.mgs4u.com/fiberglass-tube-rod.htm
--- On Thu, 4/23/09, Joe nss@mwt.net wrote:
From: Joe nss@mwt.net Subject: Re: [amsat-bb] Re: Cross Boom To: ka1rrw@yahoo.com Cc: "Jeff Yanko" wb3jfs@cox.net, "Billy Simpkins" bsimpkins31@dishmail.net, "Edward Cole" kl7uw@acsalaska.net, kq6ea@pacbell.net, amsat-bb@amsat.org Date: Thursday, April 23, 2009, 3:43 PM 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"
kq6ea@pacbell.net, "Joe"
"Billy Simpkins"
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"
"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
> Subject: [amsat-bb] Re: Cross Boom > To: "Joe"
>
"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:
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No None
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?
participants (8)
-
Billy Simpkins -
Edward Cole -
Jeff Yanko -
Jim Jerzycke -
Joe -
MM -
Nigel Gunn G8IFF/W8IFF -
Pete Rowe