LC oscilator with Quartz for a wireless doorbell

[dobrandrei]

Hy,

I'm new in the electronic domain but I know some things about electronics....,and I have this problem:

I've bought 2 wireless doorbells,and i want to change the frequency for the bouth circuits to have them work independently,each on it's own frequency.

The problem is that if i press the button of one doorbell they ring bouth.
The circuits have a transmiter at voltage of 12V/23A and a receiver at 220V .Bouth have LC oscilator,where the coil(2 turns at the receiver and 2 turns with reglable midle ) is in parallel with the capacitor of 9pF and they are using an 4069 inverter and a cristal XTAL 32KHz.(DON'T HAVE THE PCB DESIGN)

Could somebody tell me how to make this changges to have 2 doorbells working independently,and not to have problems with interfering with eachother.

I tried to modify the range of one transmiter but the other must pass true that range of the first and it comands all the receivers.
Here you can find the tipe of what kind of doorbell I bought:LUCKARM DOORBELLS(search on google)

Thank you!

 

[nico_2010]

Hello!
try to modify the 9pF capacitors at one pair of doorbells (increase/decrease) let say with 10pF or 8.2pF without touch the coils. If you have an frequency counter able to measure UHF, you can see the new frequencies (by the way these are in the range of 433 MHz).

 

[keith1200rs]

Normally they have a programmable code which is transmitted and you simply need to change the code.

Keith

 

[BADFLOPPY]

A simple try.
Just change one pair of 32KHz with other freq. nearer to 32KHz. It will be selective to that audio noise. Carrier will be same.
Experts comments needed.
Thanks