All, Yeah there are millions of devices operating in that band for all kinds of applications for just low-power (e.g. less than a watt) including Spread Spectrum Techniques under Part 15, and then factor in it’s also an ISM band under Part 18 that allows unregulated/unlimited power (although other requirements make it difficult to generate to much power) and it’s not surprising you see those sorts of levels. 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/> Follow us on social media [cid:image001.png@01DB9CC5.C348F370] linkedin.com/company/compliance-worldwide-inc [cid:image002.png@01DB9CC5.C348F370] x.com/complianceww<twitter.com/complianceww> 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: Brent DeWitt <bdew...@ix.netcom.com> Sent: Monday, March 24, 2025 1:54 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Tracking down interference at 915 MHz Hi Ken. I guess I'm not terribly surprised, since this is a Region 2 ISM band from 902-928 MHz. I am making the assumption that this measurement was made in Region 2 🙂😕 Respectfully, Brent DeWitt - AB1LF Milford, MA On 3/24/2025 1:07 PM, Ken Wyatt wrote: What really struck me was how busy the 915 MHz ISM band was utilized in an urban environment! See Figure 5 in the article. This was a swept measurement in Max Hold mode over a period of about a minute and you can see the average signal amplitude was 50 dBµV, with strong peaks from the drug store to 70 dBµV. _______________________ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 8201 Lighthouse Lane Ct Windsor, CO 80528 On Mar 23, 2025, at 12:43 PM, Ken Javor <ken.ja...@emccompliance.com<mailto:ken.ja...@emccompliance.com>> wrote: My suggestion was not for the original installation, but as a suggested fix after Ken’s troubleshoot appeared to pinpoint the source of the interference. -- Ken Javor Ph: (256) 650-5261 From: Ralph McDiarmid <rmm.priv...@gmail.com<mailto:rmm.priv...@gmail.com>> Reply-To: ***** IEEE emc-pstc List ***** <EMC-PSTC@listserv.ieee.org<mailto:EMC-PSTC@listserv.ieee.org>> Date: Sunday, March 23, 2025 at 12:08 PM To: <EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>> Subject: Re: [PSES] Tracking down interference at 915 MHz I agree Ken. Unfortunately, installation companies don’t have that degree of technical prowess or care, they just go in, do a job as fast as possible, and move on. The owner of the gas station would be oblivious to the EMC concern. Ralph From: Ken Javor <ken.ja...@emccompliance.com<mailto:ken.ja...@emccompliance.com>> Sent: March 22, 2025 4:51 PM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Tracking down interference at 915 MHz Nice. Seems as if a simpler fix would be a set of directional antennas for the gas station’s 915 MHz link, yielding higher intentional signal and if the antennas are properly oriented relative to the suspected interference source, diminishing the interference level. -- Ken Javor Ph: (256) 650-5261 From: Ken Wyatt <k...@emc-seminars.com<mailto:k...@emc-seminars.com>> Reply-To: ***** IEEE emc-pstc List ***** <EMC-PSTC@listserv.ieee.org<mailto:EMC-PSTC@listserv.ieee.org>> Date: Saturday, March 22, 2025 at 3:35 PM To: <EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>> Subject: [PSES] Tracking down interference at 915 MHz Hi All, I thought this interference hunt to a gas station price sign might be of interest to the group. https://www.testandmeasurementtips.com/spectrum-measurements-shed-light-on-sign-malfunctions/ Cheers, Ken _______________________ I'm here to help you succeed! Feel free to call or email with any questions related to EMC or EMI troubleshooting - at no obligation. I'm always happy to help! Kenneth Wyatt Wyatt Technical Services LLC 8201 Lighthouse Lane Ct Windsor, CO 80528 ________________________________ This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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