[Coco] COCO 3 for LowFER transmitter?

[KnudsenMJ at aol.com]

In a message dated 12/10/03 11:22:26 AM Eastern Standard Time, 
jdaggett at gate.net writes:

> All the software has to do is to control the DAC and when to turn it on and 
> off to the 
>  Morse code being sent. 

Use the cassette relay to key the CW carrier.  If you run the carrier 
continuous and key the audio via the DAC, you'll be output MCW, which I believe the 
FCC has banned from every band (marine and Ham) for a long time, as a waste of 
spectrum space.
Though the Lowfer band rules are probably different.

As someone else mentioned, there are BASIC ROM functions to generate sine 
waves of two freqs -- 1200 and 2400 Hz, IIRC.  There is a nice sine wave table in 
the ROMs somewhere -- 16 samples, I think.  You could build a better one with 
256 samples, and not have to filter the DAC audio output as hard, though 
audio filtering is easy with an op amp and a couple Rs and Cs.  I built some 
hardware to generate PL tone for a 2m repeater that way once, though not using a 
Coco.
--Mike K.