G1INF has an interesting example to demonstrate how simple a DC receiver can be.

http://g1inf.blogspot.com/2009/11/usb-powered-direct-conversion-receiver.html

I happen to have some SA602 on hand from a Mouser order that I placed last week. I
figured that it might be nice to have some on hand for some future projects. (I have
not worked on building any receivers yet as I am focused on simple oscillator driven
transmitters and how to build small signal gain stages at the moment.)

An interesting note in this blog post is that input impedance of the SA602 is 1500
ohms. I did not realize that but I have never really looked at the data sheet for
the SA602 in detail.

Here is a link to the datasheet:

http://www.nxp.com/documents/data_sheet/SA602A.pdf

Here are some of more interesting excerpts:

Good geeky stuff from the the blog world.

73 de NG0R