Davis anemometer transmitter problems

[RayProudfoot]

I noticed around 22:00 last night the console was reporting "Low battery on station 1". That's the ane tx positioned on a SE wall so gets plenty of sunshine. But there was an 'X' showing every 2.5 secs in the bottom right of the console which suggested a signal was being sent. There was a calm overnight and hardly a breath of wind this morning.

The warning message cleared at midnight. That is mentioned in the Davis troubleshooting guide. But I only replaced the battery last winter so I'm surprised I saw the message. I have had the Tx since I bought the VP2 back in April 2009. Only been opened a couple of times to change the battery. Hopefully not a serious problem.

What perplexes me is the 'stuck' wind readings between midnight and 08:00 yesterday. Never seen that before. Image attached.

Wind.jpg

[HansR]

Seems to me it only functions when the daylight is there, so only runs on direct solar.
Most likely the capacitor issue. See the beginning of this thread.

[RayProudfoot]

Seems to me it only functions when the daylight is there, so only runs on direct solar.
Most likely the capacitor issue. See the beginning of this thread.

But there was a signal being sent every 2.5 secs shown by the X on the console. That could only have come from the ane tx as the ISS in the garden doesn't transmit that often. With a dead calm it's not ideal to work out the problem. Sunrise is just after 06:00 but it was around 09:00 before wind measurements started.

[HansR]

Seems to me it only functions when the daylight is there, so only runs on direct solar.
Most likely the capacitor issue. See the beginning of this thread.

But there was a signal being sent every 2.5 secs shown by the X on the console. That could only have come from the ane tx as the ISS in the garden doesn't transmit that often. With a dead calm it's not ideal to work out the problem. Sunrise is just after 06:00 but it was around 09:00 before wind measurements started.

Look at the capacitor and see/show how it looks.
Maybe even better, don't talk, just replace.
I had the same problem and I replaced it: problem over.

[HansR]

And this was my repair thread.

[prodata]

It's an interesting detail that I'm not 100% sure about TBH, but I suspect that the ISS transmitter still transmits every ~2.5secs, irrespective of whether there's also an anemometer transmitter in use. So the flashing 'X' could well be reflecting the ISS transmissions and so could potentially be misleading. Two things to check:

1. Look at the wireless diagnostics screen on the console specifically for the channel that the anemometer Tx is on.

2. Visual inspection of the Anemometer Tx supercap.

[RayProudfoot]

Thanks for the replies chaps. Hans, I have limited skills so wouldn’t be confident of changing the capacitor.

John, the Reception stats for station 1 show 29% for good packets. For station 2 it’s 98%. It does appear that transmitter is only operating in good lighting. But why wouldn’t the newish battery kick in even if the capacitor was faulty?

I’m going to take a look at it now so will report back later.

[prodata]

John, the Reception stats for station 1 show 29% for good packets. For station 2 it’s 98%. It does appear that transmitter is only operating in good lighting. But why wouldn’t the newish battery kick in even if the capacitor was faulty?

AFAIK Davis have never released the circuit details for the transmitter boards, so it's a matter of conjecture as to why things happen the way they do. But it's not uncommon for faulty supercaps to cause odd symptoms. One reason is that even relatively new batteries may get exhausted quickly. But there are other possible reasons too.

[RayProudfoot]

Hi John,

The state of the capacitor doesn't look good. I scraped off some of the gunk but suspect that is the reason for the overnight dropouts. I assume I'm going to need a new capacitor. Can you supply one or alternatively, give details of the type and where it can be aquired?

I'll order a spare cartridge for the ane today as I need to get things stable before winter arrives.

VP2-Capacitor.jpg

[prodata]

Ray, suggest you give the office a call in the morning to order. (Just buying one supercap on its own is expensive because we have a minimum order value. But they should be able to quote a better price if ordered with something else.)

NB Replacing the supercap is simple provided you have some basic soldering skills. Some people prefer to leave the snipped ends of the old supercap leads in place to make somewhere easier to solder to - up to you. One caveat: Replacing the supercap doesn't guarantee a cure I'm afraid. Sometimes a faulty supercap seems to damage other parts of the circuitry and replacing the supercap may not fix the problem or may be only a temporary cure. But it's a cheap option to try as a first step and may well be successful.

[RayProudfoot]

Ray, suggest you give the office a call in the morning to order. (Just buying one supercap on its own is expensive because we have a minimum order value. But they should be able to quote a better price if ordered with something else.)

NB Replacing the supercap is simple provided you have some basic soldering skills. Some people prefer to leave the snipped ends of the old supercap leads in place to make somewhere easier to solder to - up to you. One caveat: Replacing the supercap doesn't guarantee a cure I'm afraid. Sometimes a faulty supercap seems to damage other parts of the circuitry and replacing the supercap may not fix the problem or may be only a temporary cure. But it's a cheap option to try as a first step and may well be successful.

Thanks John. I don't have the skills to solder but a friend does and he's coming on Friday / Saturday to swap out the cartridge and (hopefully) replace the faulty capacitor. I accept replacing it may not fix the problem but given I've had that transmitter since 2009 it's done well. Sadly, the cups have stopped rotating again so that cartridge will be needed. Speak to you tomorrow, thanks.

[mcrossley]

The ISS does send every 2.5 seconds-ish regardless of what is connected to it. If the console is connected to an ISS, then the "X" on the display always refers to that, regardless of it's id.

[RayProudfoot]

The ISS does send every 2.5 seconds-ish regardless of what is connected to it. If the console is connected to an ISS, then the "X" on the display always refers to that, regardless of it's id.

Roger that. Bit misleading isn't it?

[RayProudfoot]

The number of good packets now received from the Ane Tx is now 8700 and counting. Percentage of good packets is up to 45%. Does that means the circuit board is working okay despite the failure of the supercap? Presumably if the board was damaged the good count wouldn't increase.

All rather academic given the cups are not rotating.

[RayProudfoot]

Just for info. 30 mins before sunset and station 1 (ane tx) has stopped transmitting. Message of low battery on station 1 now showing on console and website.

http://www.cheadlehulmeweather.co.uk/system.htm

I don't have a spare battery so things will have to stay as they are until Friday when the capicitor can be changed and a new wind cartridge installed.