Intermittent wind speed in Fine Offset WH1080

[sdalrymple]

My fine offset stopped reporting any windspeed in December, reading just "0.0". I replaced with a new wind speed sensor from Maplin, which didn't seem to do anything, but I left it up for a couple of weeks and when I checked again it had recorded. But then that one failed again just reporting "0.0"
I contacted Clas Ohlsen, who I originally purchased it from, and they sent me another wind gauge! Again this didn't work at first, then worked fine for a week, and then stopped at 7 this morning but I see there's been a single spike recorded at 11am, other than that wind speed reads "0.0".

What is going on here and can I fix it? I have changed the batteries in the base unit and the transmitter.

[Super-T]

Perhaps a connector or cable problem. Did they supply a new cable?

[Ned]

What springs to mind is a cable connection issue, either where the anemometer plugs into the wind vane, or at the wind cable connection to the transmitter. These telephone connectors are susceptible to corrosion - check for green gunk at the connection sockets. I've restored these with scraping and spraying with WD-40 or similar.

[sdalrymple]

Apologies for taking ages to reply - been on my hols! Are all the cables just standard telephone cables? Sounds like I need to take it down, give it a clean and replace them

[sfws]

Alan ('AllyCat ') is the Fine Offset electronics 'expert', but since you get the cable with the anemometer, you have already replaced that cable. You therefore know the cable between vane and anemometer is okay, although the socket in the wind vane or the cable to the transmitter might be faulty and might indeed produce an intermittient fault like you are apparently experiencing.

To me if 3 different anemometers all result in the same problem, I would wonder if the problem is in a different part i.e. the processor/transmitter. I don't know, but I guess that could also behave eractically either because its wind socket is dirty or because the circuit board has something loose.

I suggest you do an "advanced search" just within this section of the forum for previous contributions from author AllyCat as they will explain all the options available to you as well as answering your question about the cables. An obvious test is to swap the wind and rain plugs where they plug into the transmitter, windy weather will show a lot of rain, and wet weather a lot of wind. You will have to sort out the mess of wrong values. Alternatively use a meter to check for continuity or pulses in the wind vane to transmitter wire, you will find which pin is what posted in this section of the forum somewhere.

As I understand it, the transmitters can vary in terms of transmission frequency, vary in terms of the way the processor works and vary in terms of how the zero and one states are represented (e.g. some use on/off, others vary frequency). Thus I believe if you cannot fix the problem, you will have to replace both transmitter and console as a pair, and I guess a complete new station will be a similar cost.

On my 9 year old Fine Offset I have twice replaced the anemometer, and I have changed the reed switch a couple of times too, so I don't think they are designed to last a long time, but to have a new one not working must be rare. I have not replaced my transmitter or console (fingers crossed) as I get good wind data for within a town. I don't trust either the humidity or the temperature readings on my station and measure those separately.

[AllyCat]

Hi,

I didn't respond to this particular thread because most had already been said before. Just to clarify, as a test you can plug the short anemometer cable directly into the Rain socket and rotate it a few times. But note that it may take up to 48 seconds before the reported "Rain" suddenly jumps up. That should isolate whether it's the anemometer, the cable or the transmitter at fault.

Yes, the cables are basically RJ11 "telephone" type (in the UK used only for broadband connections), but beware that the Wind Vane needs a "4-core" version, or 6 cores (RJ12) for the Solar Pod of the 308x stations.

I have myself experienced one "transmitter" (external sensor module) which failed to detect reed-switch closures (it was actually of the Rain sensor input) because it appeared to be delivering an insufficient "pull-up" current to give an adequate voltage swing. In this case it was not the well-known problem of moisture in the cable/connectors leaking away the current (emulating a permanently-closed reed). I added a pull-up resistor which temporarily fixed the problem, but then it failed again so I had to accept that the transmitter was (irrepairably) faulty. Whether it's worth replacing a faulty "external tranmitter", depends on many factors, in particular the age of the station and your location in the World.

Cheers, Alan.

[sdalrymple]

Thanks very much for all of this. Clas Ohlsen (who I purchased the original unit from in Feb 2016!) very kindly sent me a replacement transmitter unit after I identified the corrosion. Is it very easy to rewire the two cables that go into this or will I need a special crimper to fit the phone plugs on the ends?

[AllyCat]

Hi,

Yes you can probably assemble the connectors in a bench vice or with a simple "Punch Down" tool, but you can get a proper crimp tool from ebay for about £4. You might even find a seller that will bundle ten RJ11 or RJ12 (6p6c) with the crimper at a modest cost (but normally they will be the 8 contact RJ45 shells). It's usually worth looking for a pack of 10 shells (e.g. from kenable/ebay) because they needn't cost more than one or two, and will give some scope for trials or mistakes.

Cheers, Alan.

[sdalrymple]

Thank you again for this help - as I just have wind and rain sensors, is it the 6P4C RJ11?

[AllyCat]

Hi,

Yes, anemometer (speed) on the two middle pins (or Rain on the other connector) and Direction (vane) on the two "Outer" pins (of 4 in RJ11). Polarity not critical (the sensor circuit is effectively symmetrical). Contacts 1 and 6 (of RJ12, if used) are not connected.

Interestingly, the last "WH1080" Transmitter (Maplin) that I saw has a 6-contact (RJ12) socket (i.e. like the 308x solar transmitters) but only the middle contacts appear to be connected. I had wondered/hoped that it might be a "Universal" transmitter, but apparently not.

Cheers, Alan.

[sdalrymple]

Hi,

That appears to have fixed it! I'll give it a few days before I climb back up on the shed, just in case..!

Thankyou again for all your help.