[GreenKeys] SELCAL - auto start proposed

[Bob Camp]

Hi,

With out a lot of work we can probably do a single pc board sort of 
project that would make this stuff fairly easy. More or less I'd put in 
the following:

1) Some kind of fixed frequency receiver - put a single crystal as a 
filter in front of a single chip receiver.

2) A simple audio TU. Nothing very fancy but a couple 20 cent quad op 
amps go a long way.

3) A PIC to do the SELCAL, frequency voting, and to put a digital 
filter on the tail end of the TU.

4) A solid state relay to fire up the printer or at least to key the 
relay that does fire up the printer.

5) A floating loop keyer. I suspect the loop supply will be in another 
box.

None of the above stuff is very original. The receiver dates back to at 
least the early 80's (Ham Radio Magazine)	
Does it make more sense to do this all as one board or as a set of 
boards maybe three boards?

	Take Care!

		Bob Camp
		KB8TQ