Cumulus Support

Voltage regulation seems to be the problem to me with these units, atleast for some problems/differences.
A higher voltage input, maybe 4.5/5v, regulated down to 3 volts might work.
I have not done it, but maybe monitoring the battery voltage will help show
what is going on when the spikes happen.

Yes, it could well be affected by battery voltage, I agree. I'm planning to have power nearby later on anyway to run a heater for the rain gauge in the winter, so a regulated 3v supply for the transmitter wouldn't be a problem.

have you tried some ferites on both ends of the cable?
that should stop interference picked up by it.

also wind and humidity can create static electricity,
if that affects the cable or the temp.sensor directly,who knows..
grounding would be needed then.

just food for thought.might be all wrong

hans wrote:have you tried some ferites on both ends of the cable?

Just the lower end. Had no effect.

also wind and humidity can create static electricity,
if that affects the cable or the temp.sensor directly,who knows..
grounding would be needed then.

Yes, done that. Earthing (grounding) the mast did help as did using shielded/screened cable and earthing/grounding the screen.

Only had very small spikes for the last couple of days. Here's the last 24hrs.

maybe some chicken wire(?) around the outdoor sensor unit connected to ground? a sort of faraday cage?

hans wrote:maybe some chicken wire(?) around the outdoor sensor unit connected to ground? a sort of faraday cage?

The wind sensor units could be screened as could the cable between them but not the main unit (transmitter, temp, humidity) as it would stop or weaken the transmission.

silly me ,
overlooked that

what about the quality of the tempsensor,it could be coming with the type.

The temperature sensor is a thermistor. Presumably the microprocessor measures the resistance and computes the temperature from that. Whether it uses a look-up table or a formula I have no idea - all I know is that thermistors produce a non-linear value of resistance with temperature.

After all the little ones, a BIG spike - reminiscent of Glastonbury Tor

i have looked at the 24 hour graps on your site.
at the same time you see
hum.-fluctuates,
wind -gustpeak,
pressure- at a peak ,tilting from rising to falling.

looks like all is affected,which should rule out a faulty sensor,
so that could mean it is a nag in the data transmission.

improving sending/receiving might help,such as better antennas(which are 1/4 wave,you could extend them to 1/2 wave)

could be as simpel as a dirty pcb of the outside/or inside unit or bad soldering,
which is not uncommon since qualitycontrole is a big no no(to expensive)

A fixed resistor in place of the rtd would rule out the rtd if the spike was gone.

Rising spikes sure would make you suspect a bad connection.

The only way to solve this problem is to eliminate those things that are working properly.

Randy

After a quiet period with just very small spikes something seems to have happened! I shall go out and investigate later when the light is better.

I've been out and checked that the earths are all OK and they are so this is something new. And I haven't got much spare time ATM to carry out extensive investigations.

Think I'll check the batteries in the transmitter unit or, as someone suggested, try a regulated 3v supply. This is really bad!!

Gina, have you tried a small electrolytic capacitor across the battery?