Michael Black wrote in
news:alpine.LNX.2.02.1407261848390.22322@darkstar. example.org:

The one place I've seen a lot about these ICs is
http://home.comcast.net/~phils_radio_designs/
so poke around there, you may find something of value.


Nice one. Thanks. Already found two docs there I hadn't seen yet. There is a
possibility that one of the cheapest radios might be simple enough as a base
for extensive modification and addition, but I doubt that TTL level serial is
in any of them, but if I can get that it solves so many things, leaving only
experimentation with ferrite rods and coils and long wires to do, hence the
attraction...

Above all else I must avoid having the thing turn into a brick for the twenty
minutes it takes for power to fade, allowing it to be reset. That looks like
a big weakness ripe for modification in many if not all products based on
these IC's, though it may well be Tecsun's control methods that borked in the
case of the PL-390.