Superheterodyne receiver??

[smslavin]

I've been studying up for the upcoming test in Borrego and the term 'superheterodyne receiver' keeps popping up on the practice tests. A little googling has shown me what it does (frequency mixing) but I'm curious as to why that needs to be done. Are they something that need to be custom built or can you get one as an off the shelf unit? Why would you need one?

[cruiserlarry]

I've been studying up for the upcoming test in Borrego and the term 'superheterodyne receiver' keeps popping up on the practice tests. A little googling has shown me what it does (frequency mixing) but I'm curious as to why that needs to be done. Are they something that need to be custom built or can you get one as an off the shelf unit? Why would you need one?

Superheterodyne receivers are standard in most modern radios. Superheterodyne receivers have superior characteristics to simple receivers, both in frequency stability and frequency selectivity, as the main electronics in the radio need to be sensitive to only one frequency (the Intermediate frequency, or IF), instead of the entire frequency range of the receiver.

Newer radios that use microprocessors can utilize SDR, or software defined radio, that replaces the superheterodyne circuits with computer-define frequency control.

For more detailed info, check out:

SUPERHETERODYNE RECEIVERS

[smslavin]

thanks larry