[Milsurplus] [ARC5] 1625 and Key Clicks.

[Kenneth G. Gordon]

On 11 Jul 2017 at 16:21, Bob kb8tq wrote:

> Hi
> 
> Time constant - how fast do you normally send? 

Around 30 WPM, most of the time. Sometimes a bit slower. There are a group of guys 
centered around 30 kHz up from the bottom of 40 and 20 who bang along at speeds up to 
100 wpm. Some of their signals have very noticable clicks.
 
> 10 WPM is 50 characters per minute or about one a second. With normal 
> spacing, you are at a character in a second. 
> 
> If you send a series of numbers, you have about 20 elements per second. Normal
> letters will be a bit less. 
> 
> For reasonable "fidelity" you want a time constant / filter that will pass the 5th harmonic
> of your keying "square wave". That gets you to about 100 Hz or so. 
> 
> This all scales with keying speed. If you normally send at 100 WPM, 100Hz becomes 1KHz. 
> None of it is exact. You could go to "3rd harmonic" and cut them 2:1. ...You could go to the 
> 9th harmonic and double the targets. It still works either way.
> 
> Bob

Thank you for that above, Bob. I'll file it in my file on keying methods.

Much appreciated.

Ken W7EKB

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