>-----Original Message----- >From: John Woodgate [ mailto:j...@jmwa.demon.co.uk] >Sent: Friday, December 19, 2003 5:32 AM >To: emc-p...@majordomo.ieee.org >Subject: Re: Measuring a ferrite performance > > > >I read in !emc-pstc that Price, Ed <ed.pr...@cubic.com> wrote (in ><b78135310217d511907c0090273f5190d0c...@curly.ds.cubic.com>) about >'Measuring a ferrite performance' on Thu, 18 Dec 2003: > >> 2. Decide on system impedance. If 50 ohms is OK, then >just connect >> a 3 dB attenuator to each of the coax connectors. If you want >> another impedance, then put appropriate resistors (carbon comp >> preferred) into the project box. > >I suppose you put the attenuators there to minimise mismatch effects? >-- >Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL!
John: Yes, maybe an old habit. I like to keep the variables of possible signal generator source impedance and spectrum analyzer input impedance out of the investigation. Most times, that extra 6 dB path loss is no problem at all, and the 3 dB on each side of your variable condition is enough to reasonably isolate the "experimental zone." Six or ten dB would be even better; whatever works if you have the signal budget. Regards, Ed Ed Price ed.pr...@cubic.com WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty
