Re: Making an FM radio digital tuner

"realexander" <realexander@xxxxxxxxxxxxx> wrote in message
news:1114797488.414334.227450@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Hi,
>
> I'd like to build a clock radio as a hobbyist project.

Yep, decent choice, and should be useful at the end.

I had a look inside a Denon AM/FM tuner and found an LM7000 series chip.

The MPU has a Z80 core.

What you could do is get a similar radio and remove the MPU core and wire
your own board to the I/O connections. You then have to write your own
application to run the show, but all the fiddly bits are done for you.

Note that radios are usually hi-integration items, so some of the cheaper
radios merge the MPU with the radio section. You might not want to spend
cash on an expensive tuner where they might be separate.


> My question is, can anyone advise me on how to digitally tune a radio?

It is easy, just get the data *** for the chip in use.

> Alternatively, there's several FM radio kits I could buy, but they are
> tuned by variable capacitors. Is there a way to replace that with
> digital electronics?

Not much point, just buy an FM tuner.

Note that most components are surface mount so buying an existing product to
hack is cheaper than getting a board made and populated.

> Finally, I could buy a cheapo pocket radio, but it's already got an
> LCD. I doubt my ability to hack into something like that and control
> it.

I can send you the reverse-engineered cct of my TU1500.
Not guaranteed error free, but it will show you what kind of things surround
the MPU.




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