Thread: SI Disco: Poor Range for 315MHz Security Remote

excellent work there graham.....

got any pics of the work....im interested to see where exactly the antenna starts from as mine will be a bit different....defender...
the reason will be the same.....

I have done the key under the chin and it seems to work, but also I have unlocked the car from over 12 metres away when I am leaving my unit and going down the stairs I hold the remote against the window and the car unlocks?? any other time got to be stinding next to it so might try extending the remote wire as well>

I understand that while having a long range activation is nice, it's not neccessary, & for security purposes it's advisable to be near your vehicle when you unlock it. So, a few metres sounds about right for that reasoning.

Having said that, my after market immobiliser will activate/deactivate from inside the house through a window so I can see it if I need to do that ("Did I forget to activate etc?" ) & that is apx. 50m away. I would never use it that far away in a carpark.

Holding the fob on your nut also can operate the unlocking & I have simply put this down to the body making a better radiating antenna. I have wondered whether the sort of ground plane you are standing on makes a difference as well. It may have some benefit but of course you can't normally choose that.

Interesting. The 315MHz system in my P38A will work across the car park. It will work with me in the back yard and my car out in the street.

BUT - at some locations at which I work, it will not work at all, not even if I hold the remote right next to the antenna (which is bonded to the RH rear window).

For example, if I park next to the railway line at St Marys railway station when I am working the signal box there, the remote will not work. However if I park in the railway yard at Penrith (between the running lines and the sidings, there is no problem. In fact, at no other railway location do I have problems. That means there must be some RF interference at St Marys. I thought it might have been mobile phone towers but I'm not sure.

I do know that 315MHz is used for a number of products so there is a good chance that RF interference could be a problem for some owners.

Ron

Which you have just reminded me, Ron. On Mount Lofty Summit here, the RAA have placed warning signs to this effect. They get called out to unlock vehicles that have been locked with the remote.
They request drivers use the key to lock/unlock.

Mt Lofty has the 3 TV Transmission towers close by & the adjacent ( apx. 2 km line of sight) Mount Bonython has TELSTRA towers (Mobile phones & Regional links, & just over the hill is the tower for Adelaide Airport Radar & Nav Beacons & MW Links. So there is a heap of RF concentrated in the area

I tried the jawbone method and it works.
I think Ive worked out how it works.The signal goes into my hollow head bounces around heaps gets amplified and pops out thru my eyes.
Andrew

and pops out thru my eyes.

Or even your stick antenna.

what happens if you hold the remote at the same height as your chin but at arms length....?


is it your head that makes it work or the fact that you are holding the button at glass height above the metalwork.....