[GreenKeys] on-off radio teletype (not FSK)

[Dave Horsfall]

On Sat, 17 Feb 2018, Jim Haynes wrote:

> In the days of 850 Hz shift for hams, it was popular in TU designs to be 
> able to switch off one or the other tone and copy single tone.  The 
> reason was the tendency of CW operators to sit on one of the tone 
> frequencies to try to disrupt the operation.

Good grief...

-- 
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."