Robert, I checked my tabulation of drive levels for the various test levels. When testing at 10V/m and 3V/m, I do have occasional adequate drive levels. However, when I test at 1V/m, I don't have sufficient drive. On the other hand, if I am testing at a 10-3-1 sequence, the first 2 in the sequence have already "cleaned" the contact.
If I want to be sure of having cleaned contacts, I can put attenuation after the switch. This will cause my source to drive harder. I checked my numbers across the range. In my case I have 30 dB of head room, so I can easily insert 20 dB of attenuation and insure sufficient current cleaning of my contacts. Thanks for the insight. Best regards, Don From: robert Macy [mailto:[email protected]] Sent: Monday, April 21, 2003 2:46 PM To: [email protected]; [email protected] Subject: Re: Low signal switching Don, It is my understanding that physical switch contacts are "cleaned" with current - and use. It is probably ok at the lower signal levels since from time to time you're running the higher levels through the switches. Is there someway you can switch and then verify contact? - Robert - Robert A. Macy, PE [email protected] 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 On Mon, 21 Apr 2003 13:27:38 -0400 [email protected] wrote: > > 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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
