I needed to extend my anenometer cord after a relocation yesterday and didn’t have time to make up a new cable (although I will) but decided to get some RJ11 extension cords and couplers from Maplin.
I could only get 2 shielded cable sets but needed another 5m so bought there standard unshielded RJ11 cable with a socket. After wiring it all up I couldn’t get ANY readings so connected a lan tester which showed all 4 wires working fine. As a first resort for the testing I checked all the connections, which should be OK after the lan tester but still… and then decided to find a way to remove one of the leads, the first one being the unshielded 5m RJ11 extension. Immediately everything worked.
Is the signal drop really that great or something else, bearing inmind you are supposed to be able to extend approx 500? ft I have only extended by 50ish and lost signal, admittedly with several couplers, etc.
Or is the moral not to extend with unshilded cable? I think I’ll use Cat 5 to do the proper extension.
Check the wiring at the plugs. I think you will find they are crossed over.
Hold the plug up and look at the colours. You should have say black, red, green and yellow.
Hold the other end up beside this end. The colours should be oppisite. Yellow, green, red and black. If not they put the plug on that end the wrong way around.
Confuzed? #-o
Hold both plugs head-to-head like you are trying to plug them into each other. The wire colours should be the same. Black to black, red to red, green to green, yellow to yellow.
If you get black to yellow, red to green, green to red and yellow to red… wrong.
Now don’t go throw the lead away. Just chop the end off and put a new one on the other way up. It should work fine.
The cable on my Davis is unshielded. To me it looks the same as 4 core telephone cable.
how are you connecting wire to wire? I would recommend soldering each wire and individually taping electrical tape to each connection, then to the bundle, just twisting the wires is risky. they have to make connection. AND the wires have to match as Qwarla suggests.
Crossed over wires, I thought that at first, that’s why I used the lan tester, it showed the wires were connected straight through, exactly what I thought at first though :?
For connections I use RJ11 couplers, they are both still in use and working fine, I have just not used the unshileded 4-core extension yet :?
I have around 60 metres of unsheilded wire from my anenometer to the iss, and have had no problems with that over the last 2 years, I also use an rj11 connector up the pole where the anenometer transmitter used to be (I removed that and made it cabled) it has all been fine here. Maybe need to make sure the rj11 connector has all the wires through? and that there is no crossovers in that connection ?
Cheers
Geoff
with those connectors, you really have to be careful that water doesn’t seep into it from either precipitation or condensation.
Originally I had mine set that way with the idea that if the Anenometer would go bad, all I had to do is plug in my backup unit and be fine. What I discovered is that one day my readings stopped . I went out with the backup unit in hand, only to discover water had seeped in even though it was in an enclosed shelter. So I did some fast soldering on site and that took care of it for now.
What I did was originally splice the cable and then wrap thick plastic around the connections with rubber bands on each end and in the middle and it did work.
I have the same problem with extending my cable: I used normal RJ11 phone cable (4 wire) with a RJ11 coupler…no wind direction reading (always North) and no wind speed. I tried another coupler: a RJ12 (6 wire)…wind speed OK but still no wind direction.
If I use the anemometer cable directly to the ISS…no problem. Very strange!!! I tried another phone cable and it gave me no better result.
So is it necessary to use the original Davis cables and couplers to avoid these problems? But they are very expensive compared to these found in electronics shops…
Did you build the cables yourself? I would compare the pin-outs from the cable that works to the ones that don’t…I suspect off-the-shelf phone cables are not wired correctly for the anenometer. Also, I would try to build the cable long enough so you can elminate the coupler(s).
I did the same thing with my old WMII anenometer and had no problem using normal phone wire.
No…my cable is not self made. I always heard that a simple phone cable is normally OK and I amnot very used to make cables from my own…
About the ADSL cable…why not trying that?? But I ignored that ADSL uses a different cable than a 4 wire phone cable…
ADSL modem cable or network cable won’t work. They are 8 pin. Davis uses what is called a 6P 4C RJ11 connector. That means it’s 6 pins wide but only uses, or actually has 4 pins.
The problem with made cables is that they sometimes hade one end on the wrong way. This normally won’t matter with telephone equipment, as it only uses the 2 centre wires, but for other stuff, where all 4 wires are used, it does matter. If the end is on the wrong way around you have reversed polarities, so it won’t work.
A set of plastic crimping tools are very cheap and simple to use. I bought a set a long time ago and have used them hundreds of times. But if you don’t feel this is for you, I am sure you can find someone with a set you can borrow or do the job for you.
The attached some what shabby pic shows how the wires should be. The colours may not be the same, but the idea is still the same. Hold the 2 ends side by side with the locking tab the same way. If the colours are not as in the pic then that is the problem. Interesting because when you used 3 cables it didn’t work but works with 2 cables. I think what is happening is the first one reverses, then the second reverses the reversed wires so they are correct again. then the 3rd cable reverses the connections again. Standard flat 4 telephone cable is all that seems to be used. I actually shortened mine on installation. i could not see the need to have a coil of cable left hanging about. There is no evidance of sheilding on it.
Actually the standard UK, and probably european, ADSL cable is RJ11. The RJ45 (8pin cables) will not work, but they are just standard utp cables anyway.
So a standard ADSL RJ11 cable will work fine. I still haven’t been able to get the phone extension RJ11 able to work though :?
I’m new here and got a kind off a little problem. Since a few days I own a brand new cabled Davis Vantage Pro2 (EU model) on a tripod. Because my anemometerreadings were much to low, due to my garden, I placed it today on a pole on top of my roof, about 12,5 meters above the ground. On that pole is also a anemometer of my LaCrosse attached. I used an extensioncable like the ones mentioned in the above replies, and tested it, before I placed it on my roof.
When I was done with the job, the windreadings were much and much to high (about 156 km/hr) where Lacrosse had 2,6 or so km/hr. Also the windvane was giving me trouble. We had a wind from the west. By a regular interval the vane was showing north on my console, instead of west, which was the correct direction.
Off course I pulled the complete pole etc. down to check, but there were no twisted wires or so.
My question to you: Does anybody knows what’s going on with that thing? What can I do to get the right readings? Any other suggestions?
With kind regards and awaiting your answers, DJ van Dijk, from weatherstation Kollumerzwaag, The Netherlands. Check my profile for website etc.
hi
the NORTH direction will be a default reading when there is no correct reading coming from the windspeed sensor, i suspect
can you take it down again and see if you can get it going again where you first had it working for testing?
