[GreenKeys] Suggestions for telegraph demo...

[Cory Heisterkamp]

You should have pretty good luck with standard 30A automotive relay. Typically less than a buck a piece and available everywhere. Wouldn't take much to try one...  -Cory


On Jun 8, 2013, at 11:10 PM, "Derek Cohn/WB0TUA" <vibroplex at mindspring.com> wrote:

> Hi Everyone,
>  
> This year, I'm once again doing a demo for a large group of high school seniors who will be entering the Univ. of Missouri - St. Louis IT program in the fall.  There will be 33 students in this year's group.
>  
> After about 1 hour of my 2 hour window, I begin to lose the attention of the students which is normal and I want to make more of my presentation interactive with the students building their own telegraph circuit.  I have found a source of reasonably priced hand keys (the cheapie plastic ones and I can add a switch to serve as the circuit closer).  However, I need something to serve as the sounder.  I'm not aware of anyone who makes sounders anymore.
>  
> In the past, I have heard of people using noisy relays (not actual telegraph relays, but automotive or other type) that will click.  It's not critical that the device work well since the students won't know the code and won't be able to copy a message.  I just need to demonstrate the principle of how the technology works.  Can anyone suggest a relay or other device that the students can use?  I looked at Tom Perera's web site where you can wind your own sounder but I don't think that will work in the time frame I have.  Whatever I use, will have to be powered from simple batteries.
>  
> Any and all suggestions welcome!
>  
> 73,
> Derek Cohn
> Amateur Radio Station - WBØTUA
> Morse Telegraph Club - Office UD, Sine DJ
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