Cumulus Support

Because of the very high temperatures in the sun above the roof I'm going to take the temperature sensor of my WH1080 away from the roof an put it in a shadow place. So I have to connect the wind/rain sensors on the roof by extended cable to the temperature sensor (which is also the battery holder and the sender unit).

I need about 15 meters extension cable. I've got a 15 m CAT6 ethernet cable and patched it on both ends to CAT5 double network LSA+ socket (picture below). Wind speed and rain sensors work fine, but the wind vane doesn't work at all. I double checked the wiring of cause.

As I learned here, wind vane sensor gets a different resistance in the range 1K to 120K according to the wind direction. So it may be an issue of the long cable and it's resistance that cause the sender unit not to detect the right wind direction. I even tried to use both orange and brown pairs of wires to cover the wind vane signal transmission, the resistance of the single CAT6 cable is only about 2,5 ohm now. With no success.

Any ideas whether it could be possible to make 15 m extension and which cable would be suitable to make the wind vane sensor working with that extension?

Hi,

Yes it should be possible to extend the cable by that distance and I doubt if the resistance as such is the issue. But the cable actually carries the Analogue/Digital (ramp) signals so stray capacitance, leakage (moisture in connectors) and crosstalk from the anemometer reed switch can cause problems. Particularly note that the external temperature reading can be upset (perhaps one of the main causes of "temperature spikes") when the cable is extended (I'm currently working on a "project" to reduce this).

Note that the A/D converter reports "--" direction not only for resistance values significantly above and below the 700 ohm and 120k ohm normal limits, but also between many of the nominal values.

But the most likely cause is that one of the (golden) wires in the RJ11 connectors (probably in the transmitter) is not making a proper contact.

Cheers, Alan.

I made up new cables to come down from my roof to the shielded transmitter housing.

Enclosed connections in a weather proofhousing. Some spiking but I relocated my receiver and seems to have calmed down. 15m cable as well.

See below:
https://cumulus.hosiene.co.uk/viewtopic.php?f=16&t=6069

The cable resistance is trivial with respect to the resistance measurement - you'd need to run kilometers before it even gets interesting. (typical CAT5/6 is 24 AWG conductors at 0.085 ohms per meter) Far more important is how the added length affects temperature readings. (Yes, temperature).

Do a search on the forum - There's a long thread on issues with extending the cable, and Gina has done many well documented experiments where she does an excellent job of explaining the issues, solutions tried, and a final solution.