Basically, I want to make a signal cable on a proportional controller's clamp meter longer. The proportional controller "senses" whether electricity is being exported from your house via a clamp meter and ramps up a resistive load (immersion heater) to stop excess generation (from solar) being exported to the grid. Before anyone suggests I should just "do my bit" and export over generated power, this is for a prospective installation, no FiT and making the most of the generated electricity is the difference between viability of it and not. The diverted power will displace hot water heated by heating oil. It's supposed to work at up to 5m cable length. I've already made the cable longer (~10m) with some ugly old speaker cable and that works fine. I'm hoping to extend the cable to almost exactly 50m. Fortunately I have a conduit already. The clamp meter cable is thin. 0.081 mm^2 / 28 AWG. It's two wires. I think it works by the clamp inducing a current and that current being sensed back at the other end of the device. The voltage between the wires is AC and it fluctuates between ~100-300mV The current appears to be proportional to the power being drawn and it's on the scale of 0-250μA (microAmps). So... having read a little about control signal cables, it suggests that voltage drop may well be an issue with these low mV scale signals but maybe it won't either, especially if it's sensing current at the other end and I can keep the signal together over the distance. I don't know enough about exactly how the device is working (nor do I really want to) to make a proper decision based on proper calculations/estimations or even to say that it's a stupid idea. So my only instinct is to try getting the next(ish) size sheilded cable up, wiring up and seeing if it works. something like this: https://uk.farnell.com/pro-power/cbbr4162/cable-microphone-2core-black/dp/3894680 However, before I order something like that, anybody any thoughts as to if there would be anything else I could/should try to maximise my chances of success? The final issue may be that I try this longer cable and it appears to work but I accidentally introduce some horrible hysteresis into the system. I'll have to see if I can think of a way to test for this... If you've read all these waffelings, thanks so much for that alone!