Hi John, Ok thanks. I’m mixing power (Watts) vs. voltage and/or current.
If I was dealing in units of Watts, then that is where the 10 * log would come into play because I’ve already “squared” Larry K. Stillings Compliance Worldwide, Inc. Test Locally, Sell Globally and Launch Your Products Around the World! FCC - Wireless - Telecom - CE Marking - International Approvals - Product Safety 357 Main Street Sandown, NH 03873 (603) 887 3903 Fax 887-6445 complianceworldwide.com<https://complianceworldwide.com> <https://complianceworldwide.com> Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of my firm shall be understood as neither given nor endorsed by it. From: John Woodgate Sent: Tuesday, January 23, 2024 11:29 AM To: Larry K. Stillings <[email protected]>; [email protected] Subject: Re: [PSES] ANSI 63.10 2020 Clause 7.6.3 Pulsed Emissions Microvolts/m requires 20*log( ), like anything based on voltage or current. Your example of a transmitter is based on power. On 2024-01-23 16:24, Larry K. Stillings wrote: Hello All, Maybe this is not the correct forum and I should put in an inquiry into the ANSI C63.10 committee directly, however before I did that I wanted to get some help here. In the 2020 edition of the ANSI 63.10 standard they have added a calculation example page for pulsed emissions in Clause 7.6.3. In a nutshell the example shows a duty cycle of ~36% (25 mS on time / 70 mS off time). The readings are taken in dBuV/m peak values and then a duty cycle correction of 20 * log (on time / total time) is applied or -8.9 dB to determine the average value of the emission. Here is where it falls apart for me. If you are taking measurements in dBuV/m wouldn’t the duty cycle correction factor be determined with 10 * log (on time / total time). Let’s take an example of a transmitter being on 10 % of the time, isn’t that a 10 dB reduction? If the device is on 1% of the time isn’t that a 20 dB reduction? Or for some reason because it is a pulsed emission you are allowed to use 20 * log and have a 20 dB reduction for a 10% duty cycle or less because anything greater than 20 dB is the maximum allowable correction / reduction for a pulsed emission? Larry K. Stillings Compliance Worldwide, Inc. Test Locally, Sell Globally and Launch Your Products Around the World! FCC - Wireless - Telecom - CE Marking - International Approvals - Product Safety 357 Main Street Sandown, NH 03873 (603) 887 3903 Fax 887-6445 complianceworldwide.com<https://complianceworldwide.com> <https://complianceworldwide.com> Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of my firm shall be understood as neither given nor endorsed by it. ________________________________ 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]<mailto:[email protected]> All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/[email protected]/<https://www.mail-archive.com/[email protected]/%20> Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe)<https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected]<mailto:[email protected]> Rick Linford at: [email protected]<mailto:[email protected]> For policy questions, send mail to: Jim Bacher at: [email protected]<mailto:[email protected]> ________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 -- OOO - Own Opinions Only John M Woodgate, Rayleigh, Essex UK Keep trying - ---------------------------------------------------------------- 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: https://www.mail-archive.com/[email protected]/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: [email protected] Rick Linford at: [email protected] For policy questions, send mail to: Jim Bacher: <[email protected]> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
