<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>question on a related topic........I'm getting a lot of EMI/RFI
from Ethernet from some PoE powered cameras (1Ge rated, but I'm
sure they're not running that fast, maybe a 1 or 2 Mbps per
camera). The primary band that I notice it on is VHF which almost
completely trashes the spectrum. I've got 3 cameras with pretty
long shielded cat5e runs, with shielded RJ45 tips, connected to an
NVR. NVR chassis is connected to the rack single point ground
which is then connected via strap to the shack singlepoint ground
out to a grounding network of ground rods.<br>
<br>
I was able to isolate the problem to primarily the NVR and 3
cameras (everything off, spectrum looks great, turn on NVR, no
cameras connected, spectrum is trash, plug in camera 1 = more
trash, camera2 = even more trash, camera3 = most trash). Other
ethernet devices in the mix also produce a small amount of RFI
(like a serial to ethernet converter) but those runs are much
shorter and the affect is almost negligible (though I would still
like to remove the effects if possible). The runs to the cameras
are maybe 80+ ft or more.<br>
Kind of annoying because if I want to do 'clean' 2m demos, I have
to shutoff the NVR, which hurts the overall demo because now I
can't monitor the antenna motion with the video feed.<br>
</p>
<p>Not sure if the junk is getting into the front end of the receive
system and propagating back to the SDR or if its something
coupling in through the rack.<br>
</p>
<p>Any tips/hints/tricks/ etc. on how to get rid of the 2m trash or
at least how to troubleshoot would be welcome. I've looked into
Ferrite solutions, but not really sure the right place to put
them, and not sure if that would kill the actual ethernet
performance. Are there any particular ferrite type filters I
could build for this? are there existing filters on the market
for this?<br>
</p>
<p><br>
</p>
<p>I realize optical would be the way to go, but 1) I loose the PoE
feature (but could run separate DC power to each camera, so
doable) and 2) can't afford the converters at the moment.<br>
<br>
Thanks in advance!<br>
<br>
-Zach, KJ4QLP<br>
</p>
<br>
<div class="moz-cite-prefix">On 7/3/2018 3:24 PM, Bruce Perens via
Ground-Station wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAK2MWOtayMk2tceYmgO2m4otELfzTqJ7fZgJx08nk4+7jEztPQ@mail.gmail.com">
<div dir="ltr">Let's all of us hams lead a return to optical fiber
for consumer equipment, including data networking. It's easy to
show that plastic fiber is potentially cheaper than metal, and
LEDs and photosensors are cheaper than a wired Ethernet
termination with all of the little ferrites etc. While helping
the world, we will incidentally reduce RFI for ourselves.</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, Jul 3, 2018 at 11:42 AM,
Douglas Quagliana <span dir="ltr"><<a
href="mailto:dquagliana@gmail.com" target="_blank"
moz-do-not-send="true">dquagliana@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">
<div>Hi Bruce,</div>
<div><br>
</div>
<div>New houses are still being built with Cat-5e cabling,
if they even have <br>
</div>
<div>networking cables in the walls. I was going to
jokingly suggest skipping</div>
<div>the Cat-7 cabling and just waiting for Cat-8, but
Cat-8 is apparently <br>
</div>
<div>almost ready for release. However it is not intended
for general use. <br>
</div>
<div>Cat-8 is only for short runs in the data centers. <br>
</div>
<div><br>
</div>
<div>Maybe just wait for Cat-9 cabling or end-to-end fiber
without any</div>
<div>copper in the data path. After all, it will still be
called "Ethernet." :-)<br>
</div>
<div><br>
</div>
<div>Happy 4th everyone,<br>
</div>
<div>Douglas</div>
<div>(Must...Resist...Puns...With..<wbr>.Cats...And...Nines...)</div>
<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">
<div>
<div class="h5">On Tue, Jul 3, 2018 at 12:54 PM, Bruce
Perens via Ground-Station <span dir="ltr"><<a
href="mailto:ground-station@lists.openresearch.institute"
target="_blank" moz-do-not-send="true">ground-station@lists.<wbr>openresearch.institute</a>></span>
wrote:<br>
</div>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<div class="h5">
<div dir="ltr">OK, tell me why I'm an idiot :-) <a
href="https://perens.com/2018/07/03/how-should-you-ground-your-shielded-ethernet-cable/"
target="_blank" moz-do-not-send="true">https://perens.com/2018/07<wbr>/03/how-should-you-ground-your<wbr>-shielded-ethernet-cable/</a><span
class="m_2495600862597574103HOEnZb"><font
color="#888888"><br clear="all">
<div><br>
</div>
-- <br>
<div
class="m_2495600862597574103m_-3150305166183740053gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">Bruce Perens K6BP -
CEO, Legal Engineering<br>
Standards committee chair,
license review committee member,
co-founder, Open Source
Initiative
<div>President, Open Research
Institute; Board Member,
Fashion Freedom Initiative.<br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</font></span></div>
<br>
</div>
</div>
______________________________<wbr>_________________<br>
Ground-Station mailing list<br>
<a class="moz-txt-link-abbreviated" href="mailto:Ground-Station@lists.openresea">Ground-Station@lists.openresea</a><wbr>rch.institute<br>
<a
href="http://lists.openresearch.institute/mailman/listinfo/ground-station"
rel="noreferrer" target="_blank"
moz-do-not-send="true">http://lists.openresearch.inst<wbr>itute/mailman/listinfo/ground-<wbr>station</a><br>
<br>
</blockquote>
</div>
<br>
</div>
</blockquote>
</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">Bruce Perens K6BP - CEO, Legal
Engineering<br>
Standards committee chair, license review committee
member, co-founder, Open Source Initiative
<div>President, Open Research Institute; Board
Member, Fashion Freedom Initiative.<br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<!--'"--><br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
Ground-Station mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Ground-Station@lists.openresearch.institute">Ground-Station@lists.openresearch.institute</a>
<a class="moz-txt-link-freetext" href="http://lists.openresearch.institute/mailman/listinfo/ground-station">http://lists.openresearch.institute/mailman/listinfo/ground-station</a>
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Research Associate
Aerospace Systems Lab
Ted & Karyn Hume Center for National Security & Technology
Virginia Polytechnic Institute & State University
Work Phone: 540-231-4174
Cell Phone: 540-808-6305</pre>
</body>
</html>