On 28/10/2020 17:29, Max Demian wrote:
Roberts Play using FM has a bit of an echo with other (frequency
synthesiser type) FM radios.

Motorola smart phone FM radio function has a delay of about 1/3 second.
So there must be some digital processing, even with FM.

There doesn't need to be digital processing. Back in the day delays were
extremely short - a few microseconds at most - on analogue type
filters and decoders.
But it may be that if you can turn an FM signal into a sampled digital
signal somewhere in the high kilohertz band then you can apply digital
filtering and decoding to that . I know that you can use a digital TV
dingle to recieve FM...

(DAB is about 3 seconds behind.)

Well, it would be.

--
"Nature does not give up the winter because people dislike the cold."

ۥ Confucius