Ish Posted March 9, 2007 Share Posted March 9, 2007 Hi What is the maximum length you can run 12v dc power cable, rs485 cable & rg59 coax cable before there are any negative effects? Thanks Link to comment Share on other sites More sharing options...
Truss and France Posted March 9, 2007 Share Posted March 9, 2007 Ish RG59 should be good for about 300m 12volts depends on the size of the cable and loading (.75 cable with a 500ma loading should be OK for 100m) RS 485 I have had working over a 1000m but I dont know what the limit is. Hope that helps Kev Link to comment Share on other sites More sharing options...
luggsey Posted March 9, 2007 Share Posted March 9, 2007 12 volt not far depending on load and cable size. 485 comes in a few flavours, some Hi485 do 1-2KM, convert to fibre=go further. RG59, what signal type, video won't go much more then 100m without loss badly screwing up the signal, look at the loss in dB at say 100MHz in the data sheet (I have never checked the frequency of 75ohm video, anybody?) and if the length of run you have exceeds say 20dB then you will need video amps with enough dB gain to overcome the losses. Give us details, requirements, equipment used etc and more information will be available I'm sure. ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
ilkie Posted March 9, 2007 Share Posted March 9, 2007 6dB is the maximum loss acceptable on coax for CCTV video which equates to about 270m on RG59 and 210m on URM70 all from memory. This assumes good quality cable with no joints or sharp bends! More than this use larger cable or some for of launch amp/line corrector. Hope this helps Ilkie Link to comment Share on other sites More sharing options...
cutwitt Posted March 10, 2007 Share Posted March 10, 2007 Maximum cable run for RS 485 is often quoted as 1200 metres but varies with - - the data rate. - the type of cable. - the type of transceivers used. Can go as low as a 10 metres in some cases. So need more details. Link to comment Share on other sites More sharing options...
Ish Posted March 11, 2007 Author Share Posted March 11, 2007 Thanks All. I now have some general lengths to go on Link to comment Share on other sites More sharing options...
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