Gordon, I am not specifically familiar with the ESCI 7, but there will be a low frequency limit for AC coupling, below which the series capacitor presents sufficient impedance to attenuate the signal beyond the point where the instrument will meet its published specifications. This low frequency limit should be documented in the User Manual. Other instruments, that I am familiar with, have this limit on the front panel.
Best Regards, Mike From: [email protected] [mailto:[email protected]] On Behalf Of Gordon,Ian Sent: Tuesday, November 10, 2009 2:20 AM To: IEEE EMC & SAFETY PSTC Subject: AC or DC coupling in emissions measurement All I have recently been using a receiver (Rohde & Schwartz ESCI 7) which has the ability to switch between AC and DC coupling of input signals. When I use the receiver to measure the unmodulated output of a signal generator set at 150kHz & 60dBuV the receiver indicates 57dBuV when AC coupled and 60dBuV when DC coupled. Our older receiver (Teseq SCR3102) doesn't have the facility to switch between AC & DC coupling and indicates 60dBuV. I presume the receiver should indicate 60dBuV for a 60dBuV signal but which type of coupling is required by EN55011 & EN55022? Ian Gordon --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- The contents of this email and any attachments are confidential and are provided solely for the use of the intended recipient(s). If you are not the intended recipient, you are hereby notified that any copying, disclosure, distribution, or use of this e-mail, its attachments or any information contained therein is unauthorized and strictly prohibited and you should please contact the sender immediately and delete this e-mail and any attachments from your system. No responsibility is accepted for any virus or defect that might arise >from opening this e-mail or attachments, whether or not it has been checked by anti-virus software. - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]> - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]>
