How does an AM / FM switch work

[BURNY26]

So i dissassembled my radio and noticed the switch which causes a wavejump between the AM and FM signals. Does anyone know how such a switch actually works? What changes when I push the button?

 

[D.A.(Tony)Stewart]

Usually just power is switched from one radio cct to another and the outputs are just combined.

 

[BURNY26]

Usually just power is switched from one radio cct to another and the outputs are just combined.

Could you be a bit more explanatory ,im am very new at electronics

 

[D.A.(Tony)Stewart]

all radios may be different, but it is just a power switch to the different parts AM vs FM.. the common parts such as Audio share both radio output, which at least one will be silent since powered off with some transistor switch..

 

[albert22]

Trying to put it simple terms:
AM (amplitude modulation) and FM (frequency modulation) is the method by which a carrier wave is modified to transport the audio (in this case).
Broadcasting uses very different frequencies (carriers) for AM (around 1MHz) and FM (around 100MHz). The bandwidths (how wide) are different too (30Khz and more than 100Khz). This needs different tuners and different IF (intermediate frequency) amplifiers.
Also to recover the audio back you need different circuits for FM and AM. Usually they share only the audio amplifier.
All this makes that you almost need two separate radios in the same box to receive both kind of stations. A possible solution is to switch one of them on and the other off. Old radios worked like this.
Newer radios may use just one IC for the entire radio and the internal circuitry switches whatever is needed. For an example take a look at pin 15 of this IC.
https://www.electroniq.net/radio-frequency?page=14&$Version=0&$Path=/&$Domain=.electroniq.net
If you are trying to repair the radio just look how many contacts does the switch uses and how the are connected by the moving slider. And replace with an equivalent.