Loading ...
Sorry, an error occurred while loading the content.

15271RE: [wuhu_software_group] Re: Lacrosse cables and sensors

Expand Messages
  • Rob Reab
    Oct 5, 2009
    • 0 Attachment

       

      I was suggesting that shielded twisted pair would better protect against EXTERNAL RFI. Twisted pair alone, is designed to help eliminate crosstalk between the conductors as per the quotes below from CISCO.

       

      “Twisted-pair cable is a type of cabling that is used for telephone communications and most modern Ethernet networks. … The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs.”

       

      “Shielded twisted-pair (STP) cable combines the techniques of shielding, cancellation, and wire twisting. ….As specified for use in Ethernet network installations, STP reduces electrical noise both within the cable (pair-to-pair coupling, or crosstalk) and from outside the cable (EMI and RFI).

       

      Rob

       

      From: wuhu_software_group@yahoogroups.com [mailto:wuhu_software_group@yahoogroups.com] On Behalf Of Jerry Flanders
      Sent: Monday, October 05, 2009 12:32 PM
      To: wuhu_software_group@yahoogroups.com
      Subject: Re: [wuhu_software_group] Re: Lacrosse cables and sensors

       

       

      I was thinking about the run from the temp/hygro sensor to the
      console. I would be surprised if the run to the rain/wind sensors
      need RFI protection. Anyway, if you want to use it, just ignore any
      unused pairs and always use both wires of a pair - otherwise,
      immunity to outside interference is impaired. I buy this stuff at
      hamfests (electronic flea-market) for around a penny per foot, and
      wouldn't bother trying to economize with it.

      BTW, Shielding is not required if both lines of a pair are tightly
      twisted. Look up the specs on cat-5 crosstalk, etc. This is great
      general-purpose stuff. I don't know if the cables that come with the
      Lacrosse are twisted pairs. Probably not, but you could twist them
      manually to see if it helps in an RFI situation.

      Jerry W4UK

      At 12:19 PM 10/5/2009, you wrote:

      >OK, I think I understand now. I assume I can make one run to the
      >rain and wind sensor, using a different pair for each, and split
      >them out to go to the sensors, and the temp sensor on the other
      >end. Ok to leave the unused pairs open?
      >
      >Lee
      >KC4ART
      >
      >
      >
      >On 10/5/09, Rob Reab <<mailto:robreab@...>
      href="mailto:robreab%40msn.com">robreab@...> wrote:
      >
      >
      >If you're rewiring to reduce RF interference, I would suggest
      >shielded twisted pair cable. Conventional cat5 is not shielded.
      >Can't help you on the 'balance' issues.
      >
      >
      >
      >From:
      ><mailto:wuhu_software_group@yahoogroups.com>
      href="mailto:wuhu_software_group%40yahoogroups.com">wuhu_software_group@yahoogroups.com
      >[mailto:wuhu_software_group@yahoogroups.com]
      On Behalf Of lratcliff lratcliff
      >Sent: Monday, October 05, 2009 10:34 AM
      >To:
      ><mailto:wuhu_software_group@yahoogroups.com>
      href="mailto:wuhu_software_group%40yahoogroups.com">wuhu_software_group@yahoogroups.com
      >Subject: Re: [wuhu_software_group] Re: Lacrosse cables and sensors
      >
      >
      >
      >
      >
      >Ok, I am not familure with the CAT5 cable, other than knowing what it
      >
      >is. How would I wire it up as ballanced. I understand what that
      >means as far as RF feed lines, but not sure how to make it work in
      >this application.
      >
      >Lee
      >KC4ART
      >
      >On 10/5/09, Jerry Flanders
      ><<mailto:jeflanders%40comcast.net>
      href="mailto:jeflanders%40comcast.net">jeflanders@...> wrote:
      > > I should have also mentioned that I actually intended to wire up my
      > > Lacrosse 2315 with a run of cat-5 from the sensors to the console,
      > > but decided to keep it totally wireless after realizing what a nice
      > > conductor that cat-5 would provide for lightning, and the value of
      > > the electronics in the shack also hooked up to the wx computer. I
      > > will put up with changing those batteries, or maybe plug in a wall
      > > wart outside to substitute for the batteries.
      > >
      > > Jerry W4UK
      > >
      > > At 10:29 AM 10/5/2009, you wrote:
      > > >Look up the specs on common cat-5 cable. I would expect high RFI
      > > >immunity if you used it balanced as intended. I actually use a 80
      > > >foot length of it to carry the HDTV signals from my DISH
      satellite
      > > >receiver to my bedroom TV, and a second run for the stereo audio.
      > > >Works well. Common RCA plugs at each end, and no apparent problem
      > > >with the balanced-to-unbalanced transitions at each end.
      > > >
      > > >Common shielded wire may not be as good as properly connected
      cat-5
      > > >in this regard - common shielded wire usually offers less than
      > 100% shielding.
      > > >
      > > >Jerry W4UK
      > > >
      > > >At 08:30 AM 10/5/2009, you wrote:
      > > > >Has anyone tried changing out the cables on the sencors on
      the
      > > > >Lacrosse gear with something a little more imune to RF? I
      was
      > > > >thinking of something like a shielded twin conductor wire
      like is used
      > > > >in commercial audio mic cable.
      > > > >
      > > > >Lee
      > > > >KC4ART
      > > >
      > > >
      > > >
      > > >------------------------------------
      > > >
      > > >To visit your group on the web, go to:
      > > ><http://groups.yahoo.com/group/wuhu_software_group/>
      href="http://groups">http://groups
      > .yahoo.com/group/wuhu_software_group/
      > > >
      > > >Want more or less group messages (Special notices as a
      > > >minimum)?<
      href="http://groups.yahoo.com/group/wuhu_software_group/join">http://groups.yahoo.com/group/wuhu_software_group/join>
      > http://groups.yahoo.com/group/wuhu_software_group/join
      > > >
      > > >To unsubscribe from this group, send an email to:
      > > ><mailto:wuhu_software_group-unsubscribe%40yahoogroups.com>wuhu_so
      > ftware_group-unsubscribe@yahoogroups.com
      > > >
      > > >WUHU Download page:
      > > ><http://home.comcast.net/~wuhu_software/Yahoo>
      href="http://home.comcast">http://home.comcast
      > .net/~wuhu_software/Yahoo! Groups Links
      > > >
      > > >
      > > >
      > >
      > >
      > > ------------------------------------
      > >
      > > To visit your group on the web, go to:
      > >
      > <http://groups.yahoo.com/group/wuhu_software_group/>
      href="http://groups.yahoo.com/group/wuhu_software_group/">http://groups.yahoo.com/group/wuhu_software_group/
      > >
      > > Want more or less group messages (Special notices as a
      > minimum)?<
      href="http://groups.yahoo.com/group/wuhu_software_group/join">http://groups.yahoo.com/group/wuhu_software_group/join>http://groups.yahoo.com/group/wuhu_software_group/join
      > >
      > > To unsubscribe from this group, send an email to:
      > >
      > <mailto:wuhu_software_group-unsubscribe%40yahoogroups.com>
      href="mailto:wuhu_software_group-unsubscribe%40yahoogroups.com">wuhu_software_group-unsubscribe@yahoogroups.com
      > >
      > > WUHU Download page:
      > >
      > <http://home.comcast.net/~wuhu_software/Yahoo>
      href="http://home.comcast.net/~wuhu_software/Yahoo">http://home.comcast.net/~wuhu_software/Yahoo!
      > Groups Links
      > >
      > >
      > >
      > >
      >
      >No virus found in this incoming message.
      >Checked by AVG - <http://www.avg.com/>www.avg.com
      >Version: 8.5.420 / Virus Database: 270.14.3/2414 - Release Date:
      >10/05/09 06:19:00
      >
      >
      >
      >
      >
      >

      No virus found in this incoming message.
      Checked by AVG - www.avg.com
      Version: 8.5.420 / Virus Database: 270.14.3/2414 - Release Date: 10/05/09 06:19:00

    • Show all 28 messages in this topic