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CX2SA > SATDIG 07.04.08 00:00l 335 Lines 12055 Bytes #999 (0) @ WW
BID : 58107-CX2SA
Read: GUEST
Subj: AMSAT-BB-digest V3 173
Path: IZ3LSV<IW2OHX<IQ0LT<IK2XDE<F5GOV<F4BWT<YO6PLB<CX2SA
Sent: 080406/1908Z @:CX2SA.LAV.URY.SA #:58107 [Minas] FBB7.00e $:58107-CX2SA
From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: metal or non metal cross booms (kc6uqh)
2. I: Re: metal or non metal cross booms (Francesco Grappi)
3. Re: metal or non metal cross booms (w4upd)
----------------------------------------------------------------------
Message: 1
Date: Sun, 6 Apr 2008 10:04:51 -0700
From: "kc6uqh" <kc6uqh(AT)cox.net>
Subject: [amsat-bb] Re: metal or non metal cross booms
To: "Prathap Kumar" <vu2pop(AT)gmail.com>, <amsat-bb(AT)amsat.org>
Message-ID: <000601c89808$54117650$0200a8c0(AT)kc6uqh>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Suggestion,
Wood has very good strength, why not place a wood dowel rod inside a pvc
pipe with end caps to keep the weather out?
THe wood will offer the support and the pvc will protect the wood from the
elements.
Art ,
KC6UQH
----- Original Message -----
From: "Prathap Kumar" <vu2pop(AT)gmail.com>
To: <amsat-bb(AT)amsat.org>
Sent: Sunday, April 06, 2008 7:44 AM
Subject: [amsat-bb] Re: metal or non metal cross booms
> Hi
> I got the thick wall Blue PVC pipes used for plumbing wrapped in
> fibreglass
> mat and its been in use for over ten years now.
> The final OD is now about 40mm.
> It does support both my cross yagis on the rotator.
> I am also looking for the fibreglass tube with thick wall and hope to get
> some here in Bangalore and will keep you informed Gopal.
> Best 73
> Pop
> VU2POP
>
>
>
>> Gopal,
>>
>> A good decision that you made. A study by Kent, WA5VJB, shows that
>> only some sensitivity of position between elements on the antenna
>> boom impacts using a metal crossboom if the antenna is mounted in the
>> "X" confinguration. My satellite antennas are mounted this way.
>>
>> 73 Ed - KL7UW
>>
>> At 05:50 PM 4/5/2008, Gopal Madhavan wrote:
>>>I have experimented with both non-metallic and metallic cross booms after
>>>reading numerous articles on the subject some years ago. With CP antennae
>>>mounted in X configuration there seems to be hardly any difference in
>>>performance. I speak of experiments done when AO-40 was active.
>>>
>>>I now use a metallic boom as it gives very good rigidity to mount two CP
>>>antennae, a small dish for 2.4 GHz, preamps etc. Here in India I do not
>>>have
>>>the option to order a good section of fibre glass cross boom any way, and
>>>so
>>>had made do with PVC tube wrapped in fibre glass, but it eventually
>>>sagged
>>>and I had to periodically rotate it 180 degrees to keep it somewhat
>>>level.
>>>
>>>Gopal VU2GMN
>>>
>>>
>>>_______________________________________________
>>>Sent via AMSAT-BB(AT)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(AT)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(AT)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
------------------------------
Message: 2
Date: Sun, 6 Apr 2008 19:56:25 +0200
From: "Francesco Grappi" <f.grappi(AT)tin.it>
Subject: [amsat-bb] I: Re: metal or non metal cross booms
To: <amsat-bb(AT)amsat.org>
Message-ID: <000001c8980f$889e3460$0301a8c0(AT)master>
Content-Type: text/plain; charset="us-ascii"
Hi all,
Another solutions : (I did it)
Metal cross boom with, at the end of both side, 400 mm. of nylon shaft
Inside. It works great !
73" Frank
IW4DVZ
-----Messaggio originale-----
Da: amsat-bb-bounces(AT)amsat.org [mailto:amsat-bb-bounces(AT)amsat.org] Per
conto
di kc6uqh
Inviato: domenica 6 aprile 2008 19.05
A: Prathap Kumar; amsat-bb(AT)amsat.org
Oggetto: [amsat-bb] Re: metal or non metal cross booms
Suggestion,
Wood has very good strength, why not place a wood dowel rod inside a pvc
pipe with end caps to keep the weather out?
THe wood will offer the support and the pvc will protect the wood from the
elements.
Art ,
KC6UQH
----- Original Message -----
From: "Prathap Kumar" <vu2pop(AT)gmail.com>
To: <amsat-bb(AT)amsat.org>
Sent: Sunday, April 06, 2008 7:44 AM
Subject: [amsat-bb] Re: metal or non metal cross booms
> Hi
> I got the thick wall Blue PVC pipes used for plumbing wrapped in
> fibreglass
> mat and its been in use for over ten years now.
> The final OD is now about 40mm.
> It does support both my cross yagis on the rotator.
> I am also looking for the fibreglass tube with thick wall and hope to get
> some here in Bangalore and will keep you informed Gopal.
> Best 73
> Pop
> VU2POP
>
>
>
>> Gopal,
>>
>> A good decision that you made. A study by Kent, WA5VJB, shows that
>> only some sensitivity of position between elements on the antenna
>> boom impacts using a metal crossboom if the antenna is mounted in the
>> "X" confinguration. My satellite antennas are mounted this way.
>>
>> 73 Ed - KL7UW
>>
>> At 05:50 PM 4/5/2008, Gopal Madhavan wrote:
>>>I have experimented with both non-metallic and metallic cross booms after
>>>reading numerous articles on the subject some years ago. With CP antennae
>>>mounted in X configuration there seems to be hardly any difference in
>>>performance. I speak of experiments done when AO-40 was active.
>>>
>>>I now use a metallic boom as it gives very good rigidity to mount two CP
>>>antennae, a small dish for 2.4 GHz, preamps etc. Here in India I do not
>>>have
>>>the option to order a good section of fibre glass cross boom any way, and
>>>so
>>>had made do with PVC tube wrapped in fibre glass, but it eventually
>>>sagged
>>>and I had to periodically rotate it 180 degrees to keep it somewhat
>>>level.
>>>
>>>Gopal VU2GMN
>>>
>>>
>>>_______________________________________________
>>>Sent via AMSAT-BB(AT)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(AT)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(AT)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(AT)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
------------------------------
Message: 3
Date: Sun, 06 Apr 2008 12:44:22 -0600
From: w4upd <w4upd(AT)bristor-assoc.com>
Subject: [amsat-bb] Re: metal or non metal cross booms
To: kc6uqh <kc6uqh(AT)cox.net>
Cc: amsat-bb(AT)amsat.org
Message-ID: <47F91A06.8090104(AT)bristor-assoc.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I have done that in the past and it works rather well. However, PVC gets
extremely brittle over time from UV. Be sure to give it a good paint job
with some form of marine paint (anti-UV) to help preserve it. I used on
for 10 years and it was still good and give it to someone once I went to
a solid fiberglass unit. Once the PVC becomes brittle, you'll not be
able to tighten u-bolts down very tight.
I do not remember where or who, but I bought a solid 10 foot piece of
fiberglass boom 1 1/2 inch in diameter from a place in Ohio. Since UPS
would only allow up to 9 feet long, the company cut 1 foot of it off and
shipped it (including the one foot remaining). I painted it with a UV
resistant paint and it is still in use for my KLM antennas. The unit
cost about $35.00. Not sure what the cost would be now. You can also
check with your local marina or marine supply for fiberglass masting of
various sizes.
I have also used the metal boom and had the arrays at 45 degrees to the
boom and the elements and it seem to work with little impact on performance.
Reid, W4UPD
kc6uqh wrote:
> Suggestion,
> Wood has very good strength, why not place a wood dowel rod inside a pvc
> pipe with end caps to keep the weather out?
> THe wood will offer the support and the pvc will protect the wood from the
> elements.
>
> Art ,
> KC6UQH
> ----- Original Message -----
> From: "Prathap Kumar" <vu2pop(AT)gmail.com>
> To: <amsat-bb(AT)amsat.org>
> Sent: Sunday, April 06, 2008 7:44 AM
> Subject: [amsat-bb] Re: metal or non metal cross booms
>
>
>
>> Hi
>> I got the thick wall Blue PVC pipes used for plumbing wrapped in
>> fibreglass
>> mat and its been in use for over ten years now.
>> The final OD is now about 40mm.
>> It does support both my cross yagis on the rotator.
>> I am also looking for the fibreglass tube with thick wall and hope to get
>> some here in Bangalore and will keep you informed Gopal.
>> Best 73
>> Pop
>> VU2POP
>>
>>
>>
>>
>>> Gopal,
>>>
>>> A good decision that you made. A study by Kent, WA5VJB, shows that
>>> only some sensitivity of position between elements on the antenna
>>> boom impacts using a metal crossboom if the antenna is mounted in the
>>> "X" confinguration. My satellite antennas are mounted this way.
>>>
>>> 73 Ed - KL7UW
>>>
>>> At 05:50 PM 4/5/2008, Gopal Madhavan wrote:
>>>
>>>> I have experimented with both non-metallic and metallic cross booms after
>>>> reading numerous articles on the subject some years ago. With CP antennae
>>>> mounted in X configuration there seems to be hardly any difference in
>>>> performance. I speak of experiments done when AO-40 was active.
>>>>
>>>> I now use a metallic boom as it gives very good rigidity to mount two CP
>>>> antennae, a small dish for 2.4 GHz, preamps etc. Here in India I do not
>>>> have
>>>> the option to order a good section of fibre glass cross boom any way, and
>>>> so
>>>> had made do with PVC tube wrapped in fibre glass, but it eventually
>>>> sagged
>>>> and I had to periodically rotate it 180 degrees to keep it somewhat
>>>> level.
>>>>
>>>> Gopal VU2GMN
>>>>
>>>>
>>>> _______________________________________________
>>>> Sent via AMSAT-BB(AT)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(AT)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(AT)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(AT)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(AT)amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 3, Issue 173
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