<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
Floating one end of the shield makes for a good antenna for RF.
Shields on wires carrying digital signals should be grounded at both
ends. If within equipment, the cables should be dressed close to
the chassis or structure to minimize ground loop area. In this
case, this is not a consideration.<br>
<br>
David N1HAC<br>
<br>
<div class="moz-cite-prefix">On 5/30/20 11:45 AM, Tom McDermott via
TangerineSDR wrote:<br>
</div>
<blockquote type="cite" cite="mid:CACO3nRSkGA=JDBKd2LojMBEeaU7Rp2=7+4g0Hafk34vA3gY+jw@mail.gmail.com">
<div dir="ltr">
<div>I have no idea where the idea that the shield should be
unconnected at the remote end came from. <br>
</div>
<div>In my opinion this is contrary to what probably needs to be
done. I think Scotty put a jumper on that</div>
<div>line so it could be tried both ways. Normally one floats
a shield if ground return currents from some</div>
<div>external path are expected. I don't see where those would
come from in this situation.</div>
<div><br>
</div>
<div>-- Tom, N5EG</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, May 30, 2020 at 8:31
AM Julius Madey via TangerineSDR <<a href="mailto:tangerinesdr@lists.tapr.org" moz-do-not-send="true">tangerinesdr@lists.tapr.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div> <font face="Arial">Dave,<br>
I hadn't either until I saw the note from Phil. I've
been using your original small adapter board with the
Quicc connectors so haven't run into the issue yet. <br>
<br>
Two shielded RJ45 PC through hole jacks in my parts
drawer, made by BERG, have non ferrous shields.
Couldn't find the BERG part on line but DigiKey carries
several candidates. One is AMP 5558342-1, the data
sheet for which shows phosphor bronze as the shield
material. Since the shields on the RJ jacks of the
three SBC's I have are all non-ferrous, it may be that
for RJ45's, non-ferrous construction is the usual.<br>
<br>
With regard to the shielded RJ plugs on the extension
cable, since the current recommendation seems to be to
only tie the shield to ground at the 'local' end, it's
possible to remove the shield on the plug at the remote
end; just did that with one of mine.<br>
<br>
Jules<br>
</font><br>
<div>On 5/30/2020 10:34 AM, David Witten wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Jules,
<div><br>
</div>
<div>This is something I had not thought about. </div>
<div><br>
</div>
<div>It does appear that Belden does sell a line of
Cat 5+ connectors that have little or no metal in
them beyond the contacts:</div>
<div><a href="https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.belden.com%2Fproducts%2Fenterprise%2Fcopper%2Fconnectors%2Fcat-6a-jacks&data=02%7C01%7CDavid.G.McGaw%40dartmouth.edu%7Cc604d718dc0b454744bb08d804b0ab83%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637264504133494031&sdata=W0Tg8swPDEIfa0e9lfoTLN2tkgGOjxU5hk3ONa%2FTus0%3D&reserved=0" originalsrc="https://www.belden.com/products/enterprise/copper/connectors/cat-6a-jacks" shash="HLImC09lQkxdsQnvgcBRVzZmNTP+60bZI7ABbLmPpcKut5rG0cGPBslYeXEjZiAGUnE3SeLOuHqqSOqBQ+0cBX7UT7aUDOoyabRpA9He6Mc/fBwsGK9VxQBwOIlbMpXECN6NUUPBoNtYUZduKwl2TAV7TWMutiHtPBQwrSdJdLg=" target="_blank" moz-do-not-send="true">REVConnect®
Connectivity System</a>, but these appear to be
components of a building wiring system, not board
mountable jacks. Further research is required.<br>
</div>
<div><br>
</div>
<div>Dave</div>
</div>
</blockquote>
<br>
</div>
-- <br>
TangerineSDR mailing list<br>
<a href="mailto:TangerineSDR@lists.tapr.org" target="_blank" moz-do-not-send="true">TangerineSDR@lists.tapr.org</a><br>
<a href="https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.tapr.org%2Fmailman%2Flistinfo%2Ftangerinesdr_lists.tapr.org&data=02%7C01%7CDavid.G.McGaw%40dartmouth.edu%7Cc604d718dc0b454744bb08d804b0ab83%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637264504133504025&sdata=DF8NlC7fBIB0Wzqy7mlrwSfcdNaNhfgYUTbyEOjgm2I%3D&reserved=0" originalsrc="http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org" shash="wybpdQtCylivnSoNQDHYosdS2Y+sy0WwUuFIHORVm5SjcjpY6pcQWoPEEw/l4h5Kzfo7gE8P/t+rf6zlrbACjQnjSrVN1I0Y8ZBzrX0P/QTOvtBhbB4WILvG+sUZa0DQRlQWW9k9vKSKO6/bg/9tDY5WYlcVizh9O5cV6TfaPNE=" rel="noreferrer" target="_blank" moz-do-not-send="true">http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org</a><br>
</blockquote>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
</blockquote>
<br>
</body>
</html>