Old/new problem with radio system

[Benzerari]

Have come across an old/new sort of problem with EMS system, a SD in some store room was sitting happy for 2 years or so, it's dated 2007, suddenly it comes up as faulty and cleared out it self in couple of occasions, the event log shows 'intermittent' sort of fault, I found RSSI around 20 but the signal level of the SD was around 7, the normal detectors have 166 -179 as signal levels, what makes the SD to lose its signal strength till below the noise signals?...

I have replaced it by brand new one, at the panel it shows very good signal level and tested ok, but when fitted it inside the store room the signal level dropped till 35, also worked ok when tested it, but still not happy why the signal level drops at this time, even a brand new SD is fitted?

Any light?

[Graeme]

has there been anything done to that room in the lst two years i.e lots of cables run etc

[Big_Fella]

Has anything changed at the site..?

Anyone moved anything in its way, like several metal cupboards etc, just for an example?

Is the faults at random times of the day or is there a particular pattern?

Has the store had any recent pipework fitted inside/outside or even above the store room?

We've experienced problems with certain detectors on site for some strange reasons, of which:

Several taxis were parking close to a particular building causing interference when using there transmission equipment.

Also, sites close to the coast can be suspect to problems with foreign boats/ships trasmission equipment as this isn't necessary regulated abroad so they come up with some nice frequencies that you are probably operating on.

[Big_Fella]

Whats in the store room..?  Has it got distribution boards in there?

Does the detector sit fine just outside the store room?  Is the signal strength increased by opening the store room door?  Has it had a new door fitted recently?

Are cables run above the ceiling directly above the radio detector?

Might be worth positioning the detector somewhere else within the store room if you can.  I've found my moving a detector half a metre the signal strength is increased a lot, and even rotating the device.  I think the aerial is in one half of the detector, around the perimeter, so pointing it towards the panel will increase the strength a little.

[Benzerari]

has there been anything done to that room in the lst two years i.e lots of cables run etc

No things at all!

[Benzerari]

Whats in the store room..?  Has it got distribution boards in there?

Does the detector sit fine just outside the store room?  Is the signal strength increased by opening the store room door?  Has it had a new door fitted recently?

Are cables run above the ceiling directly above the radio detector?

Might be worth positioning the detector somewhere else within the store room if you can.  I've found my moving a detector half a metre the signal strength is increased a lot, and even rotating the device.  I think the aerial is in one half of the detector, around the perimeter, so pointing it towards the panel will increase the strength a little.

The store room is open to the side of a green park and no extra metal work for what so ever, I have been in charge of that site for the last 2 years or so, for both call outs and servicing..., and I may say, I know the site like my pocket..., the strange thing is that there are other detectors and sounders around, in main corridor, next rooms and kitchen but none of them has gone faulty with low signal level! strange case really!...

[Benzerari]

Fella;

You might be right in some thing, the SD is closer to the light of the store room, the store room is just a cleaner store of chemicals and so on..., would that light affect the normal operation of the radio SD? and how far from, it should be normaly? the light and the SD have been in the same position for more than 2 years with no problem...

[Big_Fella]

Try moving it away from the light, as far as you can really.

They can cause interference especially Florescent fittings.

[scouse]

there are no temp roadworks outside this building or down the road? the temp traffic lights used on our roads use radio signals to synchronise their go/stop sequence ....and they make very good RF jammers because of their range and frequency!!

[Benzerari]

there are no temp roadworks outside this building or down the road? the temp traffic lights used on our roads use radio signals to synchronise their go/stop sequence ....and they make very good RF jammers because of their range and frequency!!

used to be some road works couple of months ago, but left in peace..., but why only that SD came up faulty even it was in the back of the building facing a green park?

[Graeme]

squirrels..

[Benzerari]

Squirrels

You answered my daughter's question Grame, each time my daughter sees a squirrel she call it as usual in French, 'Ecureil', and she asks me, how is it called in English? I said as usual I don't know, and never had enough time to look for her in a dictionary...

I found it suddenly, the world is really small, you look for some thing, you get some thing else...! it’s still... always better than no thing…!   

[David Rooney]

Well that's radio for you......!!

Don't suppose the the walls are suddenly damp or anything silly....

Have you tried changing devices and checking signal strength....

Also use the TSA to monitor the signal strength in real time rather than rely on the panel reading which is only "current" if you force the detector to transmit ie. put it in tamper.

As fella said you can turn the detector (LED toward the aerial (... don't ask !!)) and move the detector for best signal strength, could also try double basing the detector - if the ceiling is a bit damp it will affect it big time.....

[Benzerari]

Well that's radio for you......!!

Don't suppose the the walls are suddenly damp or anything silly....

Have you tried changing devices and checking signal strength....

Also use the TSA to monitor the signal strength in real time rather than rely on the panel reading which is only "current" if you force the detector to transmit ie. put it in tamper.

As fella said you can turn the detector (LED toward the aerial (... don't ask !!)) and move the detector for best signal strength, could also try double basing the detector - if the ceiling is a bit damp it will affect it big time.....

Dave have you read the quote

Have come across an old/new sort of problem with EMS system, a SD in some store room was sitting happy for 2 years or so, it's dated 2007, suddenly it comes up as faulty and cleared out it self in couple of occasions, the event log shows 'intermittent' sort of fault, I found RSSI around 20 but the signal level of the SD was around 7, the normal detectors have 166 -179 as signal levels, what makes the SD to lose its signal strength till below the noise signals?...

I have replaced it by brand new one, at the panel it shows very good signal level and tested ok, but when fitted it inside the store room the signal level dropped till 35, also worked ok when tested it, but still not happy why the signal level drops at this time, even a brand new SD is fitted?

Any light?

[Graeme]

Benz

like you mention if a new device is doing the same it has to be the location and something has changed within it or nearby.