Ken, It had not occurred to me that electronic switches might do the job. I don't know if isolation will be an issue, but contact resistance is out of the picture, and I can live with a couple of dB of insertion loss. Thanks for the idea.
Best regards, Don From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, April 21, 2003 7:20 PM To: drcuthbert; 'djumbdenst...@tycoint.com'; emc-p...@majordomo.ieee.org Subject: Re: Low signal switching I can certainly suggest a solution, although it would take a bit of research to totally determine the answer. There are any number of spectrum analyzers and EMI receivers out there with switchable front-end attenuators. An HP 8566 has a noise floor of -135 dBm with a 10 Hz bandwidth and full video filtering. An NM-37/57 has a much lower noise floor and these things have been around for close to forty years, with no problems that I know of with the attenuator switches fouling. So any of the manufacturers of EMI receivers spectrum analyzers should know what swtiches to buy. I checked out Mini-Circuits: http://www.minicircuits.com/ and the only amplitude related specs there were insertion loss and vswr. > From: drcuthbert <drcuthb...@micron.com> > Reply-To: drcuthbert <drcuthb...@micron.com> > Date: Mon, 21 Apr 2003 14:58:57 -0600 > To: "'djumbdenst...@tycoint.com'" <djumbdenst...@tycoint.com>, > emc-p...@majordomo.ieee.org > Subject: RE: Low signal switching > > > Don, > > I have encountered this problem with low-level signals. It seems to vary > greatly from manufacturer to manufacturer (the company we had the best results > with went out of business). When the contact(s) became dirty I would run a DC > current and clean it. The problem would quickly return and the only real fix > was to replace the relay. One to two years of life was typical. I also would > like to know a good solution. > > Dave Cuthbert > Micron Technology > > > > -----Original Message----- > From: djumbdenst...@tycoint.com [mailto:djumbdenst...@tycoint.com] > Sent: Monday, April 21, 2003 11:28 AM > To: emc-p...@majordomo.ieee.org > Subject: Low signal switching > > > > Hello Friends, > > I have an application in which I would like to switch system signals on coax > cables. One system is 80 to 1000 MHz, the other is 1-2 GHz. I have found > coax switches by Narda, DB Products and Dow Key. Dow Key indicates that the > signals should be above -20 dBm to ensure that contact resistance doesn't > cause a problem. The others do not spec or address low signal issues. My > branches operate at -35 dBm, 0 dBm and 50 dBm. The 2 higher values are not > a problem, just the -35 dBm. Are there other companies that you are aware > of that make 50 ohm coax switches that are specified to operate at low > signal levels? Other ideas? > > Best regards, > > Don Umbdenstock > Sensormatic > > ------------------------------------------- > 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 > > 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: davehe...@attbi.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: davehe...@attbi.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: davehe...@attbi.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
