Extending Davis Sensors

Extending the Solar/UV sensors was recommended to Bashy recently. I really don’t want to chop the connector of a $300 UV sensor to splice in cable. I previously used telephone extensions with a LaCrosse, but the Arizona sun ate them up in nothing flat.

What are you guys using for the extension (as in cabling)?
Does anybody know how far you can extend the Solar/UV sensors?
Will the Davis 4-conductor 40ft extension work plug and play?

Davis 6830 (Temperature/Humidity Sensor in a passive fars) comes with an attached 25ft cable, so the T/H sensor can be extended at least that far. Has anybody extended it further?

Thank you for your support;
Steve

Davis used to publish a spec for the solar accuracy with a cable extension, but it wasn’t one that made much sense and they wouldn’t/couldn’t clarify it. FWIW it was “±5% of full scale plus 45 W/m2 per 100’” I think it’s safe to say that extending the cable will degrade the accuracy, but in my experience up to 40’ isn’t a big deal. Beyond that I would be a bit nervous.

Despite the higher price than phone extension cable I would suggest using the Davis cable which reasonably low resistance, does stand up to UV quite well, and you can be sure it will not result in crossed connections.

I believe Davis has a coupler too for joining 2 cables, i may be wrong there and it was in fact my supplier that sold from other sources
nope, im right https://www.scaledinstruments.com/product/davis-7876-040-standard-4-conductor-cable-40-ft-12-m/

No issues with 10m extensions on all sensors here

Am I correct in thinking the T/H sensor is special and needs 6-core cable?
(Yes I know extending it is ill-advised, but I’ve seen plenty here do it)

Davis don’t seem to sell those anymore - can’t find them anywhere (or the one I found is 12m which is too long for the delicate sensor to handle).
Do you think this would suffice? https://www.amazon.co.uk/d/Telephones-VOIP-Accessories/Pin-RJ11-Telephone-Cable-3m/B0034ULKF2

The one you link is 3 meters, not 12 meters. Note that it’s wired as a crossover cable so you’ll need a joiner that accounts for that. As you say a lot of people extend them without a problem so I would go ahead.

Thanks.
3m is exactly what I need. I was saying the 12m is too long, which could cause issues with interference.

Note that it's wired as a crossover cable so you'll need a joiner that accounts for that
I see now that it says the pins are reversed...

Is this one ok? https://www.amazon.co.uk/kenable-RJ12-6P6C-Cable-BLACK/dp/B0051FKFXQ/
If not do you think you could point me in the right direction? (US sites are fine)
Thanks again!

Aha I think I’ve found it
For reference: https://www.amazon.com/Cmple-Phone-Cable-RJ12-Straight/dp/B00404QWUE/

Thanks for helping me with the straight/reverse distinction

Careful! I think these cables and joiners will follow the convention for 'phone cables which are crossed over. So if you get a straight cable it may not work with a standard joiner. I would go with

https://www.amazon.co.uk/kenable-Female-Coupler-Adapter-Joining/dp/B0079I7K54/ref=pd_bxgy_107_2?_encoding=UTF8&psc=1&refRID=KWZNPFF3WNM66J1QK5NE

https://www.amazon.co.uk/kenable-RJ12-6P6C-Cable-BLACK/dp/B0051FKFXQ/

And check the continuity when I install it.

Great, thanks niko.
Will try that out.

B&Q do a white 6 core, it’s perfect and I have no issues at 10m

Just one note of caution if the cable will be exposed to the sun - UV resistance. If it isn’t stated, then my rule of thumb is… Black sheathing is usually more UV stable than white/pale colours.

Good point, mine is underground and up the back of the mast so fairly safe in that respect, there is the small amount coming out of the iss I spose I should electrical tape it.

Quote from: mcrossley on [b]Today[/b] at 10:02:26

Just one note of caution if the cable will be exposed to the sun - UV resistance. If it isn’t stated, then my rule of thumb is… Black sheathing is usually more UV stable than white/pale colours.

Good point. That’s part of why I chose the one I linked but I should have mentioned it…

Thanks for the help everyone.
I installed the new station this weekend and all went smoothly.
The straight-through 6P6C cable worked perfectly

It’s been a while since I’ve posted on this forum and I know this is an old topic, but I figured I’d respond for future reference.

I have both my solar and UV sensors extended but differently. Like the OP I opted not to cut the UV sensor’s cable due to the price of the sensor. I learned not to long ago from a Davis employee that the UV sensor can be a bit temperamental when attached to long extension cables even the Davis cables.

I have my solar sensor spliced into a 100’ Davis cable and installed on the roof. The UV sensor is connected to a cheapo 25’ phone extension cord purchased at Fry’s electronics. Both sensors seem to work just fine. I used the offset settings in Weather Display to fix the accuracy issue plus normal drift in both sensors.

One thing I will say though, on the solar sensor make sure the connections are absolutely watertight for the obvious reasons.

Initially I used those yellow cap wire splices that you snap in with pliers that Davis includes with their extension cables, but due to the fact those are permanent and the solar sensor has limited amount of cable to work with I started stripping and twisting the wires together and dipping them in clear unscented candle wax and placed the connection in a green Christmas light plug protector. I haven’t had any issues since.

Just my 2 cents.