Hi Doug We looked at doing a 10m OATS but found that at 10m you didn't have a clear 10db margin from the relevant limit line in the standards, so we're aiming for a 3m site now with a raised platform so that cable trunking, turntable wont be too much trouble (I hope!) Richard EMC Resource Network ----- Original Message ----- From: "Dave Heald" <davehe...@attbi.com> To: "POWELL, DOUG" <doug.pow...@aei.com> Cc: "EMC-PSTC (E-mail)" <emc-p...@ieee.org> Sent: Saturday, April 27, 2002 7:43 AM Subject: Re: Considering a rooftop OATS
> > Well, I can comment on the line of site interference issues: > The cell tower, while nearby, only transmits in certain ranges. Unless > the signals from the tower overload your measurement devices, this > should be managable. To check for overload, play with different > attenuators and look for an appropriate linear reduction in signal > strength with each attenuator used. This can be done before it's too > late. (i.e. when you do your antenna scan before presenting your > proposal) > The same goes for the building to building links. These should also be > on defined bands (one near my old workplace was at 2.488GHz which really > got in the way) but for the most part you should be able to get used to > them and then roughly ignore them (don't entirely ignore them though - > you may have an emission that is masked within an ambient). > The only other really bad interference generators are HDTV and really > strong local TV stations (and of course the FM radio band). All but the > HDTV can be worked around with creative resolution bandwidth management > - practice makes perfect is the best advice I can give. Unfortunately > there is nothing you can do to get around the HDTV signals other than > build yourself a precompliance anechoic chamber. > > Best Regards, > Dave Heald > > > "POWELL, DOUG" wrote: > > > > Greetings all, > > > > I am considering a proposal to build a pre-compliance OATS on the rooftop of > > our facility. I am interested in hearing any experiences along this line > > especially any unexpected difficulties that came up. > > > > I am considering a 10 meter site on a raised framework or platform with > > turntable. There are a number of air-conditioning units on the roof. If > > needed, I can place grounded chain-link fence around these as a sort of > > faraday cage. A binocular scan of the surrounding area reveals a power > > substation about 1/2 mile away. Other items in the area are a cell phone > > tower about 2 miles away and there are nearby office buildings with small > > dish antennas and the like. Some of these are undoubtedly site to site > > wireless data communication. I still need to get my antenna out on the roof > > and do a quick scan. > > > > The equipment to be testing is sometimes rather heavy and I need to consider > > an elevator or at least an equipment hoist over the edge of the roof. > > Additionally, I am considering some kind of a portable weatherproof > > enclosure over the turntable. > > > > Thanks in advance for your comments, > > > > -doug > > > > ----------- > > Douglas E. Powell, Compliance Engineer > > Advanced Energy Industries, Inc. > > Mail stop: 203024 > > 1626 Sharp Point Drive > > Ft. Collins, CO 80525 > > > > 970.407.6410 (phone) > > 970-407.5410 (fax) > > mailto:doug.pow...@aei.com > > ----------- > > > > _________________________________________ > > > > This message, including any attachments, may contain information that is > > confidential and proprietary information of Advanced Energy Industries, Inc. > > The dissemination, distribution, use or copying of this message or any of > > its attachments is strictly prohibited without the express written consent > > of Advanced Energy Industries, Inc. > > > > ------------------------------------------- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > majord...@ieee.org > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Ron Pickard: emc-p...@hypercom.com > > Dave Heald: davehe...@attbi.com > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > Jim Bacher: j.bac...@ieee.org > > > > All emc-pstc postings are archived and searchable on the web at: > > http://ieeepstc.mindcruiser.com/ > > Click on "browse" and then "emc-pstc mailing list" > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: davehe...@attbi.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
