Actually we use the clamp-on RF probes up to a few hundred MHz (we don't manufacture anything requiring compliance above 1GHz), but since it's only a trouble-shooting precompliance setup, I tend to agree that we can stay with moderate quality and price and parts.
I love the idea of using an IEEE488 driver and automating the testing, and certainly the periodic maintenance check is good advice. Thanks everyone, Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. Mobile Power web: www.xantrex.com <http://www.xantrex.com> Any opinions expressed are those of my invisible friend, who really exists. Honest. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -----Original Message----- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Thursday, May 23, 2002 12:54 PM To: Price, Ed; emc-p...@majordomo.ieee.org Subject: Re: Coaxial Switches - use with spectrum analyzer and gear? I agree with Ed that there is no problem using switches, but I don't see the need for 18 GHz, all the measurements you describe stop at 30 MHz. I don't see why Mini-Circuits would be out-of-line here, and you can check losses by using a tracking generator or known signal sources. ---------- >From: "Price, Ed" <ed.pr...@cubic.com> >To: emc-p...@majordomo.ieee.org >Subject: RE: Coaxial Switches - use with spectrum analyzer and gear? >Date: Thu, May 23, 2002, 11:53 AM >>-----Original Message----- >>From: Jim Eichner [mailto:jim.eich...@xantrex.com] >>Sent: Wednesday, May 22, 2002 12:55 PM >>To: emc-p...@majordomo.ieee.org >>Subject: RE: Coaxial Switches - use with spectrum analyzer and gear? >> >> >> >>In our pre-compliance lab, we've got a pair of LISN's, a LISN-mate type >>thing that I'll call a DMRN (DM rejection network), a >>transient limiter, >>some clamp-on RF current probes, an amplifier, the front end of the >>analyzer, and a 50 ohm terminator. All this gear is connected and >>unconnected a hundred times a day when we're deep into >>trouble-shooting, and >>I'm sick of doing up and undoing coax connectors. I don't >>trust push-on >>coax connectors. >> >>What I envision is a system with a few of these coax switches >>in it. The >>analyzer input would go to a switch that selected either the >>amp (used only >>with the clamp-on probes) or the transient limiter (used with >>the LISN's). >>The limiter input would go to a switch that selected between >>the output of >>the DMRN or the Line LISN or the Neutral LISN. Etc. You get the idea. >> >>Is there anything to stop me from using coax switches with suitable CW >>power, insertion loss, and frequency spec's? Am I headed for >>trouble if I >>have 2 or 3 of these switches in the signal path, due to cumulative >>insertion loss? >> >>Thanks for your feedback, >> >>Regards, >>Jim Eichner, P.Eng. >>Manager, Engineering Services >>Xantrex Technology Inc. >>Mobile Power >>web: www.xantrex.com <http://www.xantrex.com> >>Any opinions expressed are those of my invisible friend, who really >>exists. Honest. >> > > > Jim: > > There's no reason why you can't implement the switching system you > described. The only concern is that you use really good parts. (Your > spectrum analyzer likely has a couple of internal relays in its signal > path.) Since you likely need to measure up to about 5 GHz, I would use > components rated for up to 18 GHz. This is not the place to skimp on cost. > Don't use Dow-Key relays with SO239 UHF connectors; go with something like > Agilent relays with SMA connectors. Connect the internal paths with > semi-rigid solid-wall coax, and use a good grade of flexible external coax > cabling too. If your system is computer-controlled, you can use something > like an IEEE488 Relay Driver interface to automate the switching functions. > > Your lab procedures should be amended to include some type of periodic > verification of the loss along all signal paths. > > Regards, > > Ed > > Ed Price > ed.pr...@cubic.com > Electromagnetic Compatibility Lab > Cubic Defense Systems > San Diego, CA USA > 858-505-2780 (Voice) > 858-505-1583 (Fax) > Military & Avionics EMC Services Is Our Specialty > Shake-Bake-Shock - Metrology - Reliability Analysis > > ------------------------------------------- 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"
