[GreenKeys] How to "mechanically" generate Hellschreiber?

[Bob Camp]

Hi

Assuming the transmitter is a reasonable design it should work pretty 
well. It's probably not a good idea on a rig that keys the VFO .....

Just as I would not try to put 120 wpm CW through just any transmitter 
I would not just hook the hell setup up and run it. You may need to 
play a little with the key click filtering (if any) in the transmitter.

Hell is normally considered a 2.5 character per second mode. A normal 
sound card program produces about a 60 to 80 Hz bandwidth RF output. 
More or less your keyclick filter bandwidth is 40 Hz or less.

Sixty wpm CW runs (no surprise) a word a second. At six characters to 
the word and 5 bits per character you are keying at 30 Hz. That would 
give you a keyclick filter bandwidth of at least 90 Hz and a signal 
that is at least 180 Hz wide.

Unless you have a very unusual transmitter you should be able to just 
hook it up and go.


	Take Care!

		Bob Camp
		KB8TQ


On Dec 31, 2004, at 10:29 PM, Tom Norris wrote:

> Subject pretty much says it all.
>
> The Germans were doing it 60+ years ago, since
> the sound card hadn't been invented at the time.
> :-P
>
> Simply use a normal CW keying circuit? It's easy
> enough to generate a Hell signal and send a serial
> port to feed a keyer. My concern is the keying
> speed of Hell vs that of CW.
>
> Tom NU4G
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