Maximum Lengths

[Ish]

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

[Truss and France]

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

[luggsey]

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.

[ilkie]

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

[cutwitt]

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.

[Ish]

Thanks All. I now have some general lengths to go on