Weak RF range JA-82R - RF sensors

[MR Jim]

JA-82R and 10 of my 12 RF sensors suddenly lost communication.
Troubleshooting with Olink - Monitor RF level give: 0,05m =125% 0,2m= 50% 2m=0% signal strength.
This is very short. Must be at least 30m range.

I tried to move the control panel to another location. This to eliminate possible disorders from other devices. Same result.
I had a look at PCBs and supplyvoltages internally an no obvious problem can be seen.
I also tried setting "Higher control-panel reciever-sensetivety" (6941)

Control Panel.
Jablotron OASIS JA-82K control panel
Jablotron JA-82R radio module
Jablotron JA-82y GSM module

Sensors:
JA-81F
JA-80L
JA-83M
JA-83P
JA-86p
JA-80S

Any ideas?
Best regards Jim

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JA-82R and 10 of my 12 RF sensors suddenly lost communication.
Troubleshooting with Olink - Monitor RF level give: 0,05m =125% 0,2m= 50% 2m=0% signal strength.
This is very short. Must be at least 30m range.

I tried to move the control panel to another location. This to eliminate possible disorders from other devices. Same result.
I had a look at PCBs and supplyvoltages internally an no obvious problem can be seen.
I also tried setting "Higher control-panel reciever-sensetivety" (6941)

Control Panel.
Jablotron OASIS JA-82K control panel
Jablotron JA-82R radio module
Jablotron JA-82y GSM module

Sensors:
JA-81F
JA-80L
JA-83M
JA-83P
JA-86p
JA-80S

Any ideas?
Best regards Jim

[smith007]

I would suspect 2 things.
Connection between antenna and the base modul are have some hf problems. The preamplifier of the 82R is defective.

Do you have you restart the EMA?
Can you meassure any changes in monitoring the rf level after restart?

If you have knowledge in electronics have a look at the preamp section (see attached picture).

If not it seems you must probably exchange the 82r with a newer one.

regards Chris

[MR Jim]

(28-08-2019 17:56)smith007 schrieb:  I would suspect 2 things.
Connection between antenna and the base modul are have some hf problems. The preamplifier of the 82R is defective.

Do you have you restart the EMA?
Can you meassure any changes in monitoring the rf level after restart?

If you have knowledge in electronics have a look at the preamp section (see attached picture).

If not it seems you must probably exchange the 82r with a newer one.

regards Chris

Thank you for your support Chris.
About the restart i dont know what EMA means. I have restarted the complete control panel. Also unplugged battery.

What i maybe have left to do is a complete reset. I dont know if it might change anything.

So after restart nothing changes in RF range. Nothing changes with temperature.

I had a look in the preamp section. Only two components are semiconductors.
Bandpassfilter and dubble diod.
No obvious fault. I i had a spare i would change them but i don´t.

Regards Jim

[smith007]

EMA is an abbreviation for the german "Einbruchmeldeanlage" it means the alarm system.

Ok, a restart of the system doesn't changed anything.
A complete reset wouldn't change anything too.

A restart is the first thing to check if a controller or something else makes any trouble.

Do you have checked the antenna connection?
Loose cable or poor connections or a breach in the cable itself?

Check if all components on the systemboard seats correctly.
This step may only be done when the systemboard is completly offline.
No battery is connected and the AC plug is off.
This is very important.

As you can see in your case the board has not much components.
One controller one flash chip some passive parts in the preamp section an preamplifer.
Don't know the label on the chip.
But this one is the only thing for me which would explain the low RF-Level.

On the other hand it is easier to buy a new one.
Otherwise I don't know what we could do else.

Regards Christian

[MR Jim]

Thank you again Chris!
Finally i reicived a new JA-82R pcb board.
This solved the problem.

Compared Old and new pcb components with VI signatureanalysis and it show one small difference.
It seems to be connected directly to the 28 pin IC. If this is the case htesr is not much to do with the old PCB.
Tahnk you for great support.

[smith007]

Hi Jim,
you are welcome.

Nice to hear that your system runs again.
Thanks for your feedback.

Regards Chris