[HBR] Re: GB> RSGB Keyer

[Walt Hutchens]

Ian Wilson wrote:
> Hmm .. surely it's a blocking oscillator. One gets a string
> of dits or dahs with the key held on either side, and nothing
> with the key in the middle.

Yep.  The second stage is just a threshold circuit that creates either
dots or dashes from the input waveform.

The wikipedia articles on the various oscillator circuits should help clear up the confusion:

http://en.wikipedia.org/wiki/Blocking_oscillator

http://en.wikipedia.org/wiki/Relaxation_oscillator

http://en.wikipedia.org/wiki/Hartley_oscillator

Walt Hutchens
KJ4KV