I don't know of any field probes that are easily amenable to being filtered at their input. However, you could design a set of custom filters for your power amplifier's 50-Ohm output. I recall a Drake TV-1000-LP filter that I bought for about $25 at a Ham swap meet. It was 0 dB from DC to 30 MHz, -0.5 dB @ 50 MHz, and -65 dB @ 57 MHz. In its passband, it could pass 1 kW. Since my RI testing started at either 10 kHz or 2 MHz, I often used that filter.
I always watched Ham swap meets and dusty back shelves of surplus stores for unmarked filters (the bigger and heavier the better). You can often get these for a ridiculously low price, then go home and characterize them. Eventually, you get a nice little collection of filters that just might save you a lot of hassle. Ed Price El Cajon, CA USA -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Thursday, February 02, 2012 2:54 PM To: [email protected] Subject: Re: [PSES] IEC 61000-4-3 Field Uniformity Measurement In message <[email protected]>, dated Thu, 2 Feb 2012, Ed Price <[email protected]> writes: >But I wonder if it might not be easier, all things considered, for us >(especially the many of us who only need to do 80 MHz to 1000 MHz RI) >to just stick a set of four good low-pass filters (cut-offs at 160 MHz, >320 MHz, 640 MHz and 1000 MHz) into the amplifier output coax. The insertion loss would have to be very low, otherwise the amplifier would produce more distortion at the higher power required. But it might work. Filtered probes? No power loss problem there. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
