Ferrites on both tx and rx cables. Also, don't forget the pads at the antennas as they reduce sw. I had to use both the ferrites and 6 dB pads to eliminate swings, which were obviously not due to site geometry but cabling issues. The back edge of the OATS on the transmit side can also affect your results. You need a smooth roll-off or at least a 45 degree if you are step above ground abruptly.
Hans Mellberg Engineering Manager BACL 230 Commercial Street Sunnyvale CA 94085 USA 408-732-9162 x38 408-732-9164 fax ----- Original Message ----- From: "John Harrington" <jharring...@f2labs.com> To: <emc-p...@ieee.org> Sent: Thursday, September 18, 2003 12:05 PM Subject: NSA fun > > Hello All > > I'm having some fun with an NSA measurement. I get a swing of 8dB between > 30MHz and 45MHz horizontally polarized. At 30 MHz I get too little > attenuation (i.e. I receive too much of the transmitted signal) and at 45MHz > too much attenuation. The rest of the frequency range is good within +/-2dB > and the Vertical polarization is good at all frequencies. > > Are there any OATS Gurus out there who could shed some light on this or at > least suggest an illuminating text? > > Thanks > > John Harrington > > > ------------------------------------------- > 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: emc_p...@symbol.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > Archive is being moved, we will announce when it is back on-line. > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > 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: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
