> Many receivers used the two mentioned chips... in both commericial, > Amateur Radio and classic scanner circuits. I've seen both part > numbers converted to "tk" numbers in Yaesu and Uniden Radios.
I wanted to do a receiver based on the SA-604 and an external squelch circuit, but it is still on the projects list and it became hard to find a off the shelf 21.4MHz IF Quarature coil. > If you really were interested in more work with the mentioned > chips I can and would be happy to email you some circuit diagrams > and manuals related to the chips used in quality well engineered > designs/circuits (in pdf file format). I'd like that. > As in our poor mans repeater project... sometimes when money is > tight you try to use whatever you can get you hands on. If cheap is the goal why not just convert a MASTR-II or a Micor? The last 2 Micors I got were free and I paid $20 each for some Custom MVPs. Pretty cheap. I'd prefere designing something from the ground up vs. just converting something into the ham band.