Nearly 40 dB of variations in the link S/N ratio? Holy cat crap, Batman!
How accurate is the test equipment yielding that measurement? SNR variations of 40 dB means four orders of magnitude in signal levels relative to the noise floor, a 10,000:1 change in the power ratio. No wonder the bloody link isn't stable! Frankly I'm not inclined to trust the accuracy of those measurements over-much; it's been my experience that few people own or even have access to the kind of test equipment (like Network Vector Analyzers and Power Meters) required to properly trouble shoot microwave systems. But there obviously IS a problem. OK, now for the (hopefully) helpful part: My hunch is that the FM broadcast signal, being in relatively close proximity to your antenna mount, is generating harmonics or other spurious energy of sufficient power to overload the front end of your radio. (Sharp Q, ultra-deep microwave filters are expensive and I'd be very surprised if your radio was so equipped). So, the question before you is: How important is this site to your overall network? Is it worth the expense of having a properly trained and equipped microwave field engineer find and characterize the problem, and suggest some options for corrective measures? Sorry if this sounds a bit harsh but sometimes there aren't any easy answers to difficult problems . Hope this helps, Ted Edward J. Hatfield III, President E.J. Hatfield & Company 5142 Edgemoor Drive Norcross, GA 30071-4342 USA 1-770-209-9236 - Office 1-770-209-9238 - Fax 1-770-560-0736 - Sprint 1-678-457-8411 - Cingular 154*273*18 - NexTel -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Friday, March 30, 2007 4:01 PM To: [email protected] Subject: [WISPA] fm towers mikrotik 5.8 ptp links off an FM tower. We have a ptp link with a signal to noise of 66 to 103. Our access points will only link for a few seconds and quit. we have the exact same links on other towers that work great and the one to this fm tower will not work. any suggestions? -- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
