[GreenKeys] Why this stuff matters

[Ralph Mowery]

Hoff used a .1 uf and a series resistor of 470 ohms on the st-6.  

I don't know if it is the optimum, but has worked well enough for me on 3
different st-6 units I have.  Two home made and a Hal unit I bought off ebay
a few years back.

Ralph ku4pt


-----Original Message-----
From: greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of John Nagle
Sent: Tuesday, September 10, 2019 6:50 PM
To: greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] Why this stuff matters

> From: Jeffrey D Angus<jdangus at att.net>

Good analysis.  I've done some analyses like that.
In particular, a diode across the selector magnet
will make it drop out too slowly, causing typing errors.

You can see the snubbing I use at the output end for
my board. Very similar.

https://raw.githubusercontent.com/John-Nagle/ttyloopdriver/master/board/imag
es/schematic.png

1uf in series with 10 ohms. Also, two opposed 120V Zeners, to keep
the several hundred volt high voltage spike on turn-off out of
the rest of the system.

			John Nagle


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