"Dale Parfitt" ) writes:
Albert wrote in message ...
I hope to use the MK484 single chip AM radio at 20 kilohertz for a
very low power receiver. The spec sheet says it only goes down to 150
kilohertz however.


Has anyone used the MK484 chip below 150 kilohertz?


I know it works well at lowfer frequencies...it runs circles around my
ICOM receiver! But, I'm not sure about the minimum usable frequency.


I have the spec sheet for it (and it's more modern variant, the
MLF501), if anyone wants a copy, please speak up.


Any comments appreciated.

Hi Albert,
What is the upper freq limit on this chip? I am always looking for a good AM
dtector. 9MHz is current interest.

The articles I've seen for it (and it's basically the old ZN414), the top
of the AM broadcast band or a bit higher.

But it's meant for simple receivers. You have a single tuned circuit
at the front, and then "selectivity" comes from good AGC action. It
may run out because the selectivity is unsuitable at higher frequencies,
and not because the IC can't handle them.

Michael VE2BVW