Topic: Can I extend the anemometer cable to a Fine Offfset 1080/3080 clone?

[dave_in_gva]

Hello,

Complete newbie here but have learned a good deal on this great website over the last week or so.

I live in a townhouse in Switzerland and am considering various options for a PWS. I do not have ideal siting opportunities for a sensor array. Although I am considering either an HP1003 (a Fine Offset clone with an all in one sensor) I'm also considering a 1080 or 3080 clone where the sensors are supposedly separable.

I am wondering how separable the sensors are on a 1080 or 3080 clone. Specifically, I would like to know if I can splice in 30 m or so of cable to get the anemometer up on my roof while siting the rest of the array in a better location.

If it is possible to add such length to the cable, I'd appreciate advice on what type of cable I should use and whether I should be splicing the new cable into the middle (i.e avoiding the terminations and simply reconnecting wires then sealing with heat shrink tubing) or removing the existing terminations at one or both ends.

I've never seen the cabling on these units and the user manual doesn't provide much detail. Would appreciate the views of people with hands on experience with these units or who have done this.

Best,

Dave M

[Jáchym]

Hi Dave,
I have the FO WH1080. I also had the same problem with the anemomemeter. I extended the cable by a 10m one - you can use a normal telephone line cable with an extender. However, you need to be extremely careful about the isolation. The major problem is that it must never get wet and by wet I mean even dew is a problem. If you do not isolate it correctly, your station will report crazy values - unfortunately - this is not just affecting the wind speed, when that extender got wet, I was getting temperature spikes every 10 minutes or so and some of the other values were completely off as well.
You have to wrap some water-proof foil around it, but as I said, you also have to be careful because in the winter when it gets cold and dew forms there it is also a problem. I am not sure about the length of the cable, mine is around 10m, 30m could result in some significant interference as well.

[dave_in_gva]

Thanks Jáchym,

Your posts have been a great source of learning for me.

Presumably your concerns about moisture apply to the newly exposed joints when splicing in the new segment of cable. Over and beyond heat shrink tubing I suppose one could also apply silicone sealant at the top and bottom of the heat shrink tubing. It just seems that it should not be that difficult to get the wires inside to be as protected from moisture as in the original cable.

I may be missing something in what you say....you mention one can use a normal telephone line "with an extender"....are you talking about a telephone jack with a male and female component being used? If so, I can imagine making that less susceptible to moisture might be more challenging. What I had in mind was leaving the terminations alone and literally cutting the cable in the middle and then joining the 2, 3, 7 (or however many cables there are) cables to new cables in some suitable extension wire (be that telephone cable, CAT6 cable etc). I would simply observe what colours of wire from the original cable were joined to which colours on the extension cable and then make sure to maintain that mapping when I make the splice at the other end of the extension cable.

Would such an approach also require the waterproof foil you mention or would it be enough to simply assure that no moisture can get in the area where the two sets of junctions have been made. Given all I have seen here about siting of the array being such a critical factor I would have thought adding extensions to cables on units with separable parts of the array would be a really common topic here. I do see Davis sells extension cables etc. but their gear is well out of my budget which is around 150-200 € max.

Best,

Dave M

[Jáchym]

Hi,
well I just simply bought a telephone cable and then used this to connect them:

[dave_in_gva]

Thanks again. Hmmm....so if does seem at least that I could add some extension cabling if I go the 1080/3080 route.

Another option I am considering is a Fine Offset clone of their HP1003 model. In my case it would be the Froggit HP1003 model. As this is an all in one sensor design I would put this on my roof which would mean it would have to send the signal through a 20cm thick concrčte roof, and then through another 20 cm concrete level for our first floor.

What do people with experience here think of the transmission distance and reception in a scenario like this? Obviously there are some other internal vertical walls as well although I could site the array on the roof to be more or less vertically above the console on our ground floor. In case it matters the transmission frequency is 868 MHz. Straight line distance between the sensor array and console would be about 6 to a maximum of 10m depending on how far I offset the sensor array laterally from a position directly above the console.

The downside of this option is I would be siting the sensor array on top of a flat concrete roof. The good side is my wife would probably object to the sensor being visible and this is about the only place to not have it visible. I have seen one can make a correction to the sensor values for temperature etc in the setup so I am hopeful I can overcome some of the compromises of siting the array on the roof. Another very good thing about this option is the TFT screen which looks very nice and I am aware that one can upgrade the firmware and get a better screen display of the data using the modification files available on the net.

What do people think of my above question re transmission reception and the trade off between a 1080/3080 setup with more optimal sensor siting versus the HP1003 with its screen and perhaps less ideal (but more wife friendly) sensor siting?

Best,

Dave M

[WeatherHost]

As I recall, the provided cable plugs direct into the sending unit.  It would be better to use a longer cable direct instead of using two cables with a coupler.