Car alarm fobs

[Andrew S]

Not sure that anyone can help but thought I would ask just in case

My friend has a Maplin remote car alarm and I understand it went under the name of Shark. He needs another remote but I can't track a source for him.

To be fair, I haven't asked or been to Maolins yet and I'll get a photo of it tomorrow so you can see what it looks like

It has two buttons and when pressed it synchronises with the alarm. The second button knocks out the shock sensor of the alarm. The main button is grey and the small secondary button is green.

Do all alarms work in the same frequency?

Any advice much appreciated
Cheers
Andrew

[KOY 23]

Hi Andrew.
If it was made after around 2000 it would work at 433MHz, prior to that it would be 418MHz. However the coding used is critical. Older simple systems used a fixed code, so the same code is transmitted every time and is copyable. More sophisticated alarms use a rolling code which changes after each transmission, hence is not copyable. A number of different coding systems are used.
I would think that a Maplin system is a cheap Chinese one. I may be able to help more if you could send me a good photo (part numbers readable) of the inside of the existing fob.

[Andrew S]

Thanks John, much appreciated
Cheers
Andrew