Satellite dish install on roof

[marcus mcgee]

I am about to put a 4' foot satellite dish on the GMC roof. I got an
automatic mount from AZ RV salavage and have mounted the dish to it and
aligned the LNB. The unit raises the dish and rotates it from inside
the coach. It wheighs a bit so th question is how do I determine where
the cross members of the roof are so that I can get at least some of the
mounting bolts through a secure place. The dish lays quite flat but is
solid so the wind load on it at 70 or so will be high. Any suggestions?

I use the satellite for work to download the National Lightning
Detection Network data. That is why it has to be 4'.

Marcus

 

[bartz paul]

Marcus:

As I recall, the coach parts manual contains drawings showing the coach
structure that will give you a general idea.

I vaguely recall the possibility that somewhere in the coach shop
manual, spacing dimensions for the structure are given.

Since you say it has a high air resistance, have you considered mounting
it aft of the rooftop A/C unit or the travel pod, either of which should
provide air deflection? Another method would be to mount an aerodynamic
device ahead of the dish to deflect the air movement. Leigh Harrison
configured a short piece of 4 or 6" PVC pipe mounted ahead of his
rooftop satellite TV dish as a deflector.

Out of curiosity, what is your application in using the NLDN data? Is
the data a summary of the daily occurrence of lightning strikes? I work
a long term program constructing hazardous waste storage (temporary)
facilities and one of the features we use is lightning protection. Was
wondering if the data would be of any use in our designs? If so, how do
I access it?

Paul Bartz

From: Marcus McGee [mailto:crsalert]
Sent: Wednesday, August 05, 1998 6:49 PM
Subject: GMC: Satellite dish install on roof

I am about to put a 4' foot satellite dish on the GMC roof. I got an
automatic mount from AZ RV salavage and have mounted the dish to it and
aligned the LNB. The unit raises the dish and rotates it from inside
the coach. It wheighs a bit so th question is how do I determine where
the cross members of the roof are so that I can get at least some of the
mounting bolts through a secure place. The dish lays quite flat but is
solid so the wind load on it at 70 or so will be high. Any suggestions?

I use the satellite for work to download the National Lightning
Detection Network data. That is why it has to be 4'.

Marcus

 

[thomas g. warner]

Dimensions are in one of the old GMC motorhome marketplace. I will look for
it later. I do remember that all dimensions are taken from the first rib on
the roof where the antenna was mounted, and are the same for 26" and 23'
with the exception of the most rearward rib..

>Marcus:
>
>As I recall, the coach parts manual contains drawings showing the coach
>structure that will give you a general idea.
>
>I vaguely recall the possibility that somewhere in the coach shop
>manual, spacing dimensions for the structure are given.
>
>Since you say it has a high air resistance, have you considered mounting
>it aft of the rooftop A/C unit or the travel pod, either of which should
>provide air deflection? Another method would be to mount an aerodynamic
>device ahead of the dish to deflect the air movement. Leigh Harrison
>configured a short piece of 4 or 6" PVC pipe mounted ahead of his
>rooftop satellite TV dish as a deflector.
>
>Out of curiosity, what is your application in using the NLDN data? Is
>the data a summary of the daily occurrence of lightning strikes? I work
>a long term program constructing hazardous waste storage (temporary)
>facilities and one of the features we use is lightning protection. Was
>wondering if the data would be of any use in our designs? If so, how do
>I access it?
>
> Paul Bartz
>
>From: Marcus McGee [mailto:crsalert]
>Sent: Wednesday, August 05, 1998 6:49 PM
>Subject: GMC: Satellite dish install on roof
>
>I am about to put a 4' foot satellite dish on the GMC roof. I got an
>automatic mount from AZ RV salavage and have mounted the dish to it and
>aligned the LNB. The unit raises the dish and rotates it from inside
>the coach. It wheighs a bit so th question is how do I determine where
>the cross members of the roof are so that I can get at least some of the
>mounting bolts through a secure place. The dish lays quite flat but is
>solid so the wind load on it at 70 or so will be high. Any suggestions?
>
>I use the satellite for work to download the National Lightning
>Detection Network data. That is why it has to be 4'.
>
>Marcus
>
>

 

[patrick flowers]

>
> Dimensions are in one of the old GMC motorhome marketplace. I will
> look for it later. I do remember that all dimensions are taken from
> the first rib on the roof where the antenna was mounted, and are the
> same for 26" and 23' with the exception of the most rearward rib..

Actually, that might have been in GMC Motorhome News. Seems like I
remember Wes responding with the rib spacing to someone that was wanting
to mount a pod or something like that on the roof.

Patrick
- --
Patrick Flowers
Mailtoatri63

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

[homebase1]

> From:
> Date: Fri, 7 Aug 1998 02:25:35 EDT
> To: gmcmotorhome
> Subject: Re: GMC: Satellite dish install on roof
> Reply-to: gmcmotorhome

> > Dimensions...................
> >Actually, that might have been in GMC Motorhome News.
>
> Right you are, Patrick. It was GMC Motorhome News ( from Cinnabar ) Volume
> 10, December 1996. Starting from the antenna (which is centered in the first
> rafter), the other rafters are at 41.7", 83.4", 129.5", 166.8", and 202.8".
> (I hope Wes won't mind me plagiarizing his data. You really should get the
> issue cited, as it gives further details about parallel rafters, etc.)
>
> Rick Staples
>
>
> XXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXX
A thought...
If one was to purchase a metric tape measure the numbers become, in
centimeters: 41.7 (105.9), 83.4(211.8), 129.5(328.9), 166.8 (423.7),
202.8(515.1). Round these numbers off and you'll still hit that last
rafter with lots to spare......this ain't brain surgery. A millimeter
or three isn't a factor.
Was GM gearing up to go metric in the 70's ?
As I said, just trying to make it easier....

Mikeb