Hi Ron, Sounds something like a grid dip meter. I wrote an article about using a grid dip meter for this purpose July 2002. The link is:
http://emcesd.com/tt2002/tt070102.htm Although inexpensive, a live plot showing all the resonances and how they move as things are changed is very useful. Doug [email protected] wrote: Hi Doug A simple way is to use an echo-box:- an oscillator with a loop antenna tied into the tuning circuit with a meter measuring the current in the oscillator with a fixed voltage source. As the circuit is tuned, the resonances peak. The loop antenna is connected by a dual banana plug so different bands loops can be inserted. Coupling is by proximity of the loop so anything that resonates will show up on the current meter and no physical connection is necessary. I havent seen them in many years but they should still be around. Ron Miller Doug Smith wrote: Happy New Year everyone! I been running lots of experiments and taking data over the holidays. The first result of all this activity is my Technical Tidbit for January, 2008. The link to the article is the picture of a spectrum analyzer and two currentprobes at the bottom of the page at http://emcesd.com[1] . This month's Technical Tidbit discusses a method of using a spectrum analyzerwith a tracking generator and a pair of current probes to determine the resonant frequencies of wires and cables. This method can be used to findEMC and other noise problems in equipment. Abstract: A technique for using current probes to measure cable resonances isdescribed. A swept frequency voltage is induced on a cable by one current probe and the resulting current measured using a second one. This technique can be especially useful in troubleshooting EMC emissions problems as well asother noise related problems in equipment designs. This quick and easy method can be applied to a new design for which circuit boards do not even exist yet to avoid EMC and noise problems. The method has many potential uses inside and outside of system enclosures. Doug -- ------------------------------------------------------- ___ _ Doug Smith \/ ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: [email protected][2] \ _ / ] \ _ / Website: http://www.dsmith.org[3] ------------------------------------------------------- 1 http://emcesd.com 2 mailto:[email protected] 3 http://www.dsmith.org To unsubscribe from si-list: [email protected] with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: [email protected] with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: http://www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu -- ___ _ Doug Smith \ / ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: [email protected] \ _ / ] \ _ / Website: http://www.dsmith.org - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
