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Re: US Towers



Be VERY careful with crank up towers and wind loads.  All of the US Towers
models are rated at 50 MPH winds.  An 18 to 24 sq foot load at 50 MPH is cut
about in half at 70 MPH.  So at 70 MPH, it will only handle around 9 to 12
sq feet.  If you have higher winds that that, be ware.

I know this because I have just gone through deciding on whether or not to
purchase a crank up tower from a ham I know.  We sometimes have 90 MPH wind
gusts here and I decided it was just not safe.

Your winds may be lower.  I think you can usually get wind profiles from
county offices, weather service, etc.

Fortunately, VHF/UHF and Microwave equipment has less wind loading than HF
antennas (OK, big arrays excluded).  Keep in mind also, that if you live in
an area where you have ice storms that you increase wind load as well.  BBQ
dishes have a lot of surface area for ice to attach to.

For more information on crank-up towers, look at the Tower-Talk archives on
www.contesting.com or join the Tower-Talk reflector.

73,

Jon
NA9D

on 10/19/01 12:15 AM, John Stephensen, KD6OZH at kd6ozh@gte.net wrote:

> I used one for my AO-13 antennas. It supported two crossed yagis on 144 MHz,
> 2 on 432 MHz and two on 1296 MHz. The wind load was about 12 square feet.
> 
> 73,
> 
> John
> KD6OZH
> 
> ----- Original Message -----
> From: <sco@sco-inc.com>
> To: <amsat-bb@AMSAT.Org>
> Sent: Sunday, 14 October 2001 04:25 UTC
> Subject: [amsat-bb] US Towers
> 
> 
>> Has any used the US Towers TMM (compact) series tower (41ft) for satellite
>> work? Info says they handle 18-24 sq ft wind load.
>> 
>> How much wind load is the Myers style bbq dish (S band)?
>> 
>> W4SCO
>> 
>> ----
>> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
>> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>> 
> 
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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> 


-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)

Member:  ARRL, AMSAT, DXCC, NRA

http://www.qsl.net/ke9na

"A life lived in fear is a life half lived."

----
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