Identify the frequency of the crystal used for outgoing calls in mobile phones.

Question

Question

This question was previously asked in

ALP CBT 2 Electronic Mechanic Previous Paper: Held on 21 Jan 2019 Shift 2

Answer 1

In a mobile phone, a 26 MHz crystal oscillator is located on PCB build with metal which is found near PFO in most of the mobile phones.
PFO is the type of IC found in the network section near antenna switch which is also called as an amplifier or bandpass filter. It filters and amplifier the network frequency.
The crystal oscillator filters the network and creates frequency for outgoing calls.
There will be a problem in the mobile phone networks and outgoing calls if it gets faulty.

26 June 1

The important components of mobile phones are as follows:

1) Charging IC.

2) Antenna point.

3) RAM.

4) VCO.

5) RX filter and TX filter.

6) P.F.O

7) Flash IC

8) CPU.

9) 26 MHz crystal oscillator.

10) ROM.