how the heck does FM work,? (lemmy.world)

submitted 2 months ago by Grumpydaddy@lemmy.world to c/askelectronics@discuss.tchncs.de

5 comments fedilink hide all child comments

Kind of an ELI5, but I tune a radion into a specific frequency to listen to a station. If that frequency is constantly being modulated (changed), how is the radio not going in and out of tune? I expect it is finding a way to measure multiple frequencies around the tuned station and decodes the data from it's deviation from the tuned frequency?

you are viewing a single comment's thread
view the rest of the comments

[-] drspod@lemmy.ml 13 points 2 months ago

The FM tuner is a narrow band pass filter centered at the carrier frequency - it doesn't try to track the modulation. The FM demodulator then uses a VCO (voltage controlled oscillator) with a phase detector in a feedback loop, so that the output of the VCO tracks the modulated input signal. The input to the VCO then represents the baseband (demodulated) signal.

this post was submitted on 09 Jul 2024

29 points (93.9% liked)

Ask Electronics

3173 readers

1 users here now

For questions about component-level electronic circuits, tools and equipment.

Rules

1: Be nice.

2: Be on-topic (eg: Electronic, not electrical).

3: No commercial stuff, buying, selling or valuations.

4: Be safe.

founded 1 year ago

MODERATORS

DavideAndrea@discuss.tchncs.de

linker3000@discuss.tchncs.de