Davis VP2 anemometer - strange issue (110mph winds!)

[Uncle_Barty]

Hi all,

Having a strange problem with my Davis Vantage Pro and anemometer.

Setup is anemometer on roof + cable + 10m extension > ISS >  VP console.

Been this way since 2009 when I replaced the Weather Monitor II (can't remember if I've had to replace the anemometer due reed switch failure in that time, but definitely have either before or since).

Suddenly, about a week ago, I started internittently recording winds of over 100mph, either briefly, or for minutes or hours at a time.

I have a spare anemometer, and the WMII still works. So...

I tried running the roof anemometer into the old WM2, works fine, both before and after the extension cable, no erroneous winds.

I tried unplugging the roof anemometer and plugging the spare one into the extension cable, into the VP, no erroneous winds.

I replaced the extension cable during the week as the previous one was spliced with a chocolate block, this is a proper screened 4 core cable supplied with RJ11 plugs.

The only thing I have not changed is the female-female RJ11 adapter - I am waiting for a replacement to arrive tomorrow. The join is in a wall mounted waterproof box.

I really don't understand this. The ONLY time I get errors is with the roof anemometer plugged into the VP ISS, all other combinations are fine.

I have had anemometer failures before (reed switch failure), but never this. On Monday, I will call out my aerial man and get him to put the spare anemometer up (I will leave the existing one up as well)

Has anyone else had this issue/got any ideas what the problem could be? I really don't understand this.

 

[The PIT]

The only thing I can think off is the rj11 connector but then I guess that was in use when you were doing the other tests.

Just checking the wiring for monitor that has it's own junction box so I guess rj connector wasn't used.

Edited June 3, 2023 by The PIT

[The PIT]

Sounds like you're getting intermittent short I say this as the input is held high so when it's goes to zero this counted as a pulse.

The next question is the anemometer the older one that uses a reed switch?

See

Anemometer & Vane

WWW.WXFORUM.NET

 

Edited June 3, 2023 by The PIT

[Uncle_Barty]

I replaced the RJ11 female back-to-back adapter on Sunday evening and it seems to have solved the problem.... at least, no sign of a recurrence in the 48 hours since.

Looking at the one I replaced... there is just the hint of green in the small gap where I can see the rails, so perhaps the hint of corrosion of some sort.

Begs the question, however,  as to why the fault manifested itself with one anemometer (on the roof) but not the other (the spare as supplied when I bought the VP2 in 2009) - they are both reed switch types.

[The PIT]

You probably did enough to disturb the corrosion or were just plain lucky while you were testing.