<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="">N5PA was interested in the what the lawnmower would do, and I had a chance to look at that. The image below (I’m not positive the list can take attachments) is a crude and not proofread illustration of the data. My mower is just a steal deck battery powered self-propelled mower that looks like a normal gas push mower. The times indicated by the vertical red lines were inserted into the timeline based on timestamps of photos from my cell phone, so for the two “big” events there is a lag between me fumbling with the phone and getting the photo. Below the first panel of graphs is all the data I have for that day to provide some context. So it’s clear that when the mower was really close to the magnetometer (and stationary), it produced a large signal, but when examined in context of the day it was just a very minor spike that I’m guessing could be easily ignored. By the time I was working on the central part of the yard, the signal hardly shows up. </div><div class=""><br class=""></div><div class="">I’ve got more data on parked cars which seem to have a larger, or at least more persistent signal, although in an initial test a car about 70 feet away produced very little, if any signal, I would like to narrow down what that distance really is. Cars within ~32 feet still create a signal, although I don’t know to what extent that would degrade the usefulness of the data (that would be an interesting conversation to have with those using the data). -David KE8QEP</div><div class=""><br class=""></div><div class=""><img apple-inline="yes" id="6D4A2F40-292B-432C-8A44-58D75CC19558" src="cid:1F4E9DB4-BDF3-46EA-A512-C9B3A2673536" class=""><br class=""><div class="">
<div class="">David A. Waugh, Ph.D.<br class="">Research Assistant<br class="">Department of Anatomy and Neurobiology<br class="">NEOMED<br class="">4209 State Route 44<br class="">Rootstown, OH 44272</div>
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<div><br class=""><blockquote type="cite" class=""><div class="">On Jun 28, 2021, at 8:33 PM, n5pa <<a href="mailto:n5pa.dx.341@gmail.com" class="">n5pa.dx.341@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class="">Tnx for the info David!<br class=""><br class=""><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><i class=""><b class="">73,</b></i><br class=""><i style="font-weight: bold;" class="">Alan Clark, N5PA<br class=""></i>Ellisville, MS<br class="">Email: <a href="mailto:n5pa@n5pa.com" title="mailto:n5pa@n5pa.com" class="">n5pa@n5pa.com</a><br class="">URL: <a href="http://www.n5pa.com/" title="http://www.n5pa.com/" class="">http://www.n5pa.com</a></span></div><div dir="ltr" class=""><br class=""><blockquote type="cite" class="">On Jun 28, 2021, at 7:22 PM, David Waugh <<a href="mailto:dwaugh@kent.edu" class="">dwaugh@kent.edu</a>> wrote:<br class=""><br class=""></blockquote></div><blockquote type="cite" class=""><div dir="ltr" class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class="">Alan, I’m new to the project and can’t answer your question. I think there was some theoretical limit for the cable length, but I can’t remember the number. My understanding with is that with a distributed network of sensors, local noise can be filtered out (or maybe in some cases corrected), so your lawn mower (and mine) will show up as a momentary spike and could either be “smoothed" or cut from the dataset. I would assume some of this early data will help the end users (of the data) figure out what sorts of setups are usable, and come up with strategies to filter the data as needed. The more sensors available the more can be done, even if each sensor location has some occasional temporal issues. One can never have enough data, and data is never perfect. -David KE8QEP<br class=""><div class="">
<div class="">David A. Waugh, Ph.D.<br class="">Research Assistant<br class="">Department of Anatomy and Neurobiology<br class="">NEOMED<br class="">4209 State Route 44<br class="">Rootstown, OH 44272</div>
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<div class=""><br class=""><blockquote type="cite" class=""><div class="">On Jun 28, 2021, at 7:16 PM, n5pa <<a href="mailto:n5pa.dx.341@gmail.com" class="">n5pa.dx.341@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
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David:
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<div class="">Good info on the Magnetometer tests! I wonder what effect my zero turn mower would have running over it when it is buried or my heat pump running. What would be the maximum distance you can run the cable?<br class="">
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<div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><i class=""><b class="">73,</b></i><br class="">
<i style="font-weight: bold;" class="">Alan Clark, N5PA<br class="">
</i>Ellisville, MS<br class="">
Email: <a href="mailto:n5pa@n5pa.com" title="mailto:n5pa@n5pa.com" class="">n5pa@n5pa.com</a><br class="">
URL: <a href="http://www.n5pa.com/" title="http://www.n5pa.com/" class="">http://www.n5pa.com</a></span></div>
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<blockquote type="cite" class="">On Jun 28, 2021, at 5:59 PM, David Waugh via TangerineSDR <<a href="mailto:tangerinesdr@lists.tapr.org" class="">tangerinesdr@lists.tapr.org</a>> wrote:<br class="">
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<div dir="ltr" class="">Tangerine list folks, with the help of Jules for suppling the boards (and help along the way), I was able to get the magnetometer running. Currently the magnetometer is buried about 2.5 feet in the ground under my deck. I have plans to to move
it farther away from the house and driveways if needed. Attached is a short run (not perfect graphs) I made this morning with some notes about moving the cars around (purposefully to record the influence). The cars were parked maybe 30 feet from the magnetometer.
Clearly they show up (moving the cars around), but it seems as if might be easy to correct, or recognize and ignore the disruptions. I can do some more tests, and a better “write up” to try and come with a distance for which periodically moved parked cars
show up in the data if people in the group think that might be useful. I’m excited about the project and look forward to collecting more data. I will post again once I have some longer runs, but if there is anything that I can examine, specifically, that would
be helpful, please let me know. -David -KE8QEP
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<div class=""><cars_moving_June_28.pdf></div>
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<div class="">David A. Waugh, Ph.D.<br class="">
Research Assistant<br class="">
Department of Anatomy and Neurobiology<br class="">
NEOMED<br class="">
4209 State Route 44<br class="">
Rootstown, OH 44272</div>
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