[GreenKeys] Big Bird Loop Interface

[Richard M. Gillingham]

Gonna push a '28 here, was going to do one of my own, but if y'all wanna do
it.......  Sure, Why not..

Gil, W1RG
----- Original Message -----
From: "gil smith" <gil@vauxelectronics.com>
To: <greenkeys@mailman.qth.net>
Sent: Saturday, February 22, 2003 3:55 PM
Subject: Re: [GreenKeys] Big Bird Loop Interface


> Hey Big Bird group:
>
> Jack, George, and I have been mulling over a little circuit board to add
to
> the dovetrons for directly driving a current loop from the dovetron 232
> output, and sensing loop data for sending to the dovetron tx section.
Jack
> already has a tempest dovetron he has been looking at.  Unless you are
> planning to drive a 232 printer, or already have a 232-to-loop converter,
> we presume you will want some way to drive your TTY machines.
>
> So how about a little poll?  I'd like some feedback as to what features
you
> folks might like in such a board:
>
> - do you care at all?  Or, do you already have a 232-to-loop adapter to
use?
>
> - do you want to drive a high-voltage loop (120-150V for M14/15/19/28...),
> or a low-voltage loop (30-45V for M32...)?
>
> - how many tty loop jacks should be available?
>
> - would you mind drilling holes in your dovetron to add a board inside?
>
> - would you rather mount it externally in a box and connect to the
dovetron
> BNC connectors?
>
> - would you rather mount it externally in a box but connect to a DB-9
> connector that you add to the dovetron?
>
> - do you plan to use half-duplex (single-loop rx/tx), or full-duplex (two
> loops for rx and tx)?
>
> - would you want to add an optional chip or two for doing automatic speed
> conversions and/or baudot/ascii conversions?  Then you would no longer
need
> to worry about machine gears -- demod to any speed machine.  I have
already
> done most of this code.  This can also automaically insert CR CR LF LTRS
at
> 72 chars (or N chars), or add an LF after a CR that has none...  Tell me
> what you want.
>
>
> This interface will be similar to the TTY232 board I did before -- a fully
> opto-isolated 232 to loop interface.  But, based on your feature feedback,
> would likely be simpler, smaller and would have a soldermask and silk
> screen this time.  I think I will offer bare-board only, or full parts
kit,
> to make it easier for folks to get started.
>
> thanks,
>
> gil
>
>
>
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