Impedance Mismatch

[13392017]

All,
I need your guidance in my problem following.

We would like to buy a communication cable to transmit the signal from signal source to the final actuator. The signal transmitted by mean of MODEM.

The distance from the source is about 23 km. We already have about 10 km cable, and we would like to buy the rest of cable.
I do have a cable characteristic of the 10 km cable. And i try to source the vendor that have an identic cable characteristic, but no luck.

I am notice that the signal may not transmitted correctly if there is impedance mismatch. As i am not an expert in this area, i need your guidance in this issue.

I am really appreciate if there is some guidance on how to ensure the cable that i will buy is ok or not.

Best regards,
RK

 

[MacGyverS2000]

You plan on transmitting a signal via modem through 23km of nothing but cable?

Good luck with that...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[itsmoked]

Can you put repeaters along the way?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Skogsgurra]

The early atlantic telegraph cables were a lot longer than 23 km. And they were 'nothing but cable'.

So, it can be done. The problem may be what speed you need. If you need to transmit MB or kB, it may be a problem. But if you only need to transmit a signal to an actuator and if that signal is just on/off - then it is certainly possible without any modem. A small polarized relay and a DC signal is used for that purpose in many installations.

If you need a complete protocol and duplex signalling, a low speed RS485 link may be able to cover that distance if the environment isn't too noisy.

You need to hire someone that can help you with this.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[MacGyverS2000]

Sure, but they weren't be driven by a standard modem, either...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[VEBill]

If only there was some sort of alternative electrical communications mechanism, one that could cover 23 km, but without needing cables or wires. Let call it "wireless"...