Sandaysoft

Hi All,
I have an Oregon WMR928 with 3 extra sensors.
I've recently had my domestic oil tank replaced and the installers have fitted a Watchman Sonic to monitor the oil level. So far I've had 6 different units fitted as they all failed to correctly display the oil level. The receiver cycles from showing 3 bars (correct reading) to empty every 22 seconds.

Both the Watchman and the Oregon transmit/receive at 433Mhz and the Watchman suppliers reckon the weather station is interfering with their monitor.

I've trawled the posts here and discovered that others have suffered interference from neighbouring weather stations.

Anyone had any similar experience with non weather station equipment?

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I haven't had any similar experience, however, ANY device which transmits on or near your weather station frequency can cause interference with any other device and the opposite is also true.

Some weather stations operate in the 900Mhz band which doesn't seem to be as much of a problem.

Apparently, from what you've told me, your weather station's transmitter is interfering with the Sonic. I'm going to presume the actual pole you have the weather station transmitter mounted on is in close proxmity of the Sonic, would that be fair to say? If not, then odds are they're both very close to the same frequency.

If they ARE in close proximity, you may be able to overcome the problem by relocating your weather station's transmitter further from the Sonic. If you can relocate it further away, its signal will probably be attentuated and may no longer interfere with it.

One other way would be to provide some shielding around the Sonic to further attenuate the signal from your weather transmitter...but that could also cut down the signinal FROM the Sonic too.

You're between a Sonic and a hard-place. Try shielding first...then if possible, relocate your weather transmitter.

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Steven



http://cactusjunction.info/weather

Hi Steven,

Thanks for your response. I have the weather station transmitters located at 2 points in the garden and they are both 100 feet from the oil tank transmitter.

To try to eliminate interference, I pulled an extension lead out from the house to the tank and put the Sonic receiver within 3" of the transmitter and it still errored The manufacturers have installed thousands of these things, apparently without problems, so it's something local to me.

I don't have any near neighbours except an airbase about 2 miles away. Radar? Secret weapons? Death rays?

I guess my next step is to pop the batteries in the weather station transmitters.

Cheers,
Dave

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Dave,

Sticky wicket!

Ideally, the further the seperation between your weather station transmitters and the oil tank unit receiver the better.

Perhaps it has nothing to do with the weather station transmitter. What about power lines? Do you have any power lines in proximity to the oil-tank receiver unit? Is there a large transformer on a power pole in the vacinity that could be arcing? Inspect the connections on the oil unit...perhaps shield electrical connections with tin-foil. There are so many things that can radiate (and re-radiate) that frequency that it often becomes finding a needle in a haystack. There are "harmonics" which simply means a signal of, say 112 Mhz can re-readiate and 224Mhz (doubling) then again at 448 and etc....with each harmonic becoming weaker as it strays from the original frequency. Malfunctioning power transformers, cfl light bulbs can do it...and a signal 2 miles away if its strong enough or if the signal is "beamed" your direction with a directional antenna.

If your weather station transmitters are 100' from the oil unit, I seriously doubt they would be the problem. Not impossible...but improbable in my opinion.

Perhaps another on this forum can offer you even more ideas...the physics, however, remain the same.

If the oil-tank receiver is malfunctioning because of interference, it has to have a source and the source has to be strong enough to have the ill-effect.

Good luck, Dave in hunting it down....

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Steven



http://cactusjunction.info/weather

Many thanks Steven,
I have power lines (33kV?) running alongside my property but the transformer is about 400 yards away.
I don't think it is cfl's as it happens during daylight too.

Is there any way I can "listen" to the 433Mhz frequency. I'm not a radio amateur so only have TV and radio receivers.

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How close are the high-voltage lines to the oil sensor? They, undoubtedly, can cause problems and the power company is responsible for cleaning up the radiation if that turns out to be your culprit. Sometimes, if the towers are metal, they just need to be grounded otherwise they serve as large inductive antennas.

Doubtful the transformer would be doing that at 400 yards away.

If you have a friend with a scanner radio that tunes that portion of the band, you can listen...but it may not be of any help. An oscilloscope would be the best way to monitor that frequency spectrum if you know a ham who owns one. The power company has the equipment, tho, to come out to your house to confirm whether or not the problem is theirs.

If these lines are in close proximity, I'd certainly give them a call and tell them you suspect the radiation is interfering with your equipment! They have to inspect when they receive a complaint...at least in this part of the world they do.

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Steven



http://cactusjunction.info/weather

Dave
Was it the salesman from the oil company that told you they have installed thousands and NEVER had a problem ??

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Terry Wiltshire
http://www.janter.co.nz/weather/index.htm

Steven, the power lines are on wooden poles and probably more than 100 feet from the oil sensor. I'll give the power company a call on Monday.


Yes it was but these sensors have been around for a number of years, the majority from the manufacturer of the one I've got.

The sensor is working properly this morning 09:15 (Saturday) I wonder if it will go wrong again on Monday? Perhaps somebody local has a big motor.
I'll keep a log to see if there is a pattern emerging.

10:24 Spoke too soon, it is now doing it again

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100' isn't really too far when it comes to high-voltage lines. They can easily radiate 2 or 3x that far if they're not properly setup or maintained. I agree with your decision to call the power company. It costs you nothing and may just help in locating the nasty bugger.

[quote="beeman"]Steven, the power lines are on wooden poles and probably more than 100 feet from the oil sensor. I'll give the power company a call on Monday.

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Steven



http://cactusjunction.info/weather

I have WMR928 and 6[1] extra sensors and a WMR200, all operating on 433MHz.


I have a power monitor issued by our electricity supplier. It is a 433MHz device. I've never been able to get it to synchronise between its sensor and console.

Perhaps worth mentioning that none of the OS devices have a 22 second transmit cycle. The WMR928 anemometer transmits once every 15 seconds, the other types of sensor transmit either once every 45 seconds or once a minute.

[1] The WMR928 console can of course only see 3 of them, I use an RFXCOM (http://www.rfxcom.com) receiver and Meteohub to read the full set of WMR928 and the WMR200 wireless sensors!

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Regards
David

why not move the whole kit and kaboodle to anopther place for testing.....just to prove if it is local interfernce or not?

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Terry Wiltshire
http://www.janter.co.nz/weather/index.htm

Yes, if practical.

If its the 33 kilovolt, high-voltage line though, within 30 meters proxmity, there's probably no place one could move it that would escape the wrath of it short of, say, a couple hundred meters (in my humble opinion). It may require that later...but I think he's correct in requesting the power company to come out there first to verify they have a "clean" installation. They usually don't. If this is the culprit, it could be affecting his weather station readings too...along with LOTS of other things. Some say even the health of humans.

Tricky stuff.

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Steven



http://cactusjunction.info/weather

No, I mean to move it to somewhere else like 3 kilometres away

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Terry Wiltshire
http://www.janter.co.nz/weather/index.htm

That's one hell of a long oil pipe or did you mean move the weather station??

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Yeah....I think we're all talking about moving the weather station but I remain unconvinced that has anything to do with the problem. The output of the weather station transmitter, in relationship to the output of ungrounded 33Kv high-voltage lines is like comparing the size of a marble to a railroad boxcar. The weather station transmitter just isn't that strong. I don't know for certain (somebody else here probably does) but I'm guessing its output is measured in milliwatts...like under 1 watt.

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Steven



http://cactusjunction.info/weather