It's always a good idea to get a spectrum analyzer & some antennas and do a
site survey before you build either the OATS or the shielded room. Knowing
what the ambients are in advance can save you a lot of trouble and money in
both cases.
It makes sense, but hardly anyone does it. why? because they tend to
think of the shielded room as part of the "build out" i.e. as office space,
instead of as what it really is: an electronic instrument. like an antenna.
Lou
At 12:22 PM 5/5/99 -0700, you wrote:
>I second that opinion. My experience shows SEVERE ambient issues with
rooftop sites.
>--
>Sincerely,
>
>Randall T. Flinders
>EMC Engineer
>Emulex Network Systems
>V: (714) 513-8012
>F: (714) 513-8265
>[email protected]
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>
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>Orange County Chapter
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>
>
>----------
>From: Hans Mellberg
>Sent: Wednesday, May 05, 1999 7:59 AM
>To: [email protected]; [email protected]; Gary McInturff
>Cc: 'Brent DeWitt'; Allen Tudor; [email protected]
>Subject: Re: Precompliance Testing
>
>
>
>Before you put a rooftop OATS, (assuming you are not located in Easter
>Island or the Caribean Islands!) you are going to deal with
>substantially higher ambient signals. It so happens that when you need
>a stronger signal, a common practice is to raise the antenna! I have
>battled those problems twice in my past and I would not reccomend
>rooftop OATS anymore.
>
>
>--- [email protected] wrote:
>> May I add a note of caution:
>> It may be worthwhile to check the permissible
>> loading of the roof, especially
>> when you are in the Southwest where roofs are mostly
>> for shade and a few drops
>> of rain. I guess that you don't want to appear
>> suddenly in the conference room
>> below....
>> Bogdan.
>>
>> Gary McInturff wrote:
>>
>> > I'll agree with Brent, and others, the headaches
>> of a metal room or the
>> > metal studs et al, in a building are going to make
>> you pull your hair out.
>> > But there is an alternative to the parking lot.
>> You may want to consider the
>> > roof. The ground reference can be put up there as
>> well, especially if you
>> > are doing pre-compliance stuff. You don't have to
>> give up parking space -
>> > which is sure to irate somebody. The roof gets a
>> little hot, but that only
>> > gives you the opportunity to work in your cutoffs,
>> and showing up to a
>> > meeting with the suits dressed like this is always
>> good for a laugh!
>> > Gary
>snip
>
>===
>Best Regards
>Hans Mellberg
>EMC Consultant
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