AVR-Chat

Yes, I'm still trying to define which way we'll go so that's why I wanted to 
see what chips are available in case there is something that will get me 
close.

Regarding sampling at RF, it looks like undersampling is an option that 
works but I don't quite understand all the implications... looks interesting 
though.  Of course, if I bring the level up first.

The bandwidth is only about 1KHz, but the level will be 1uV and below.
I can't use a ready made scanner, but maybe some chips "they" use in 
scanners.
One problem is most chips are for higher frequencies now...

Thank you,

Cat

> And what kind of signal (modulation)? There are very few "chips" that fit
> these requirements. Most of what is available (as full receivers) is
> tightly constrained to FM broadcast band or channelized TV reception.
> The real challenge, as previously suggested, is not the selection of an IC
> for the receiver. The biggie is the design of filters (antenna to linear
> amplifier, linear amplifier to mixer, if, etc). This is for a more or less
> conventional superheterodyne receiver. For a direct conversion, antenna to
> amplifier to ADC, you have a really big challenge getting the signal
> amplified to the level that an ADC can handle AND a challenge with an ADC
> that has a high enough sample rate. And, with that sample rate comes a
> very high bit-rate data stream. 'Tis not for the faint of heart nor the
> "gotta have it now".
>
> There are a number of "scanners" on the market that probably include that
> range, but they are rarely characterized as "low noise" or "high
> stability". They DO tend to offer a variety of demodulators (but rarely
> handle single-sideband (SSB) very well). Many scanners seem to be limited
> to a low-end frequency around 50MHz or so, though there ought to be
> something lower.
>
> There may be a few general coverage receivers out there. I would check the
> HRO (Ham Radio Outlet) website to see what might be available. They should
> also have scanners.
>
> Jim Wagner, KA7EHK
> Oregon Research Electronics
> Tangent, OR, USA