News for hackers. Stuff that matters.

A comment on Norway switches off FM radio, but a station is defying government order. Parent comment

Re:Norway switches off FM radio, but a station is defying go... by pdelbarba on Friday December 15, 2017 @03:11PM (#15934660)
Sure, but that's on the receiver side for carrier recovery. Wouldn't it be problematic if you mashed a bunch of channels/allocations sufficiently close together that they started wandering on top of each other?
[ Parent | on HN ]
Re:Norway switches off FM radio, but a station is defying go... by PoachedSausage on Saturday December 16, 2017 @10:36AM (#15939957)
Modern DAB/DVB receivers are usually zero-IF, the wanted band of frequencies is mixed down to baseband and filtered with a sharp cutoff Surface Acoustic Wave filter then sampled with a fast ADC. Selectivity is then dependent on DSP.

On the transmit side, you have to carefully combine the outputs of your various transmitters with a complex filter network, which at high powers looks something like:

http://admin.mb21.co.uk/tx/userimages/8448proc20120403120238...

[ Parent | on HN ]