[GreenKeys] New Loop Converter Prelim specs

[Roy Norris]

>
>- Nobody seemed to care about storing and replaying test messages or
>answerback strings.  But what about a test message to the local tty loop
>with a programmable amount of distortion?  Tell me how these test sets
>inject distortion.


Having the ability to transmit the "quick brown fox ..." message and a line 
of RYRY would be nice for bench testing TTY machines.  I would certainly 
like to see that.  Being able to transmit with various levels of distortion 
is not so important now that most tty keying circuits no longer use polar 
relays.  It could be done but would greatly complicate the design as it 
would require variable timing for each of the data bits and their position 
within their windows as defined by the start pulse and the stop pulse.  In 
my opinion, not worth the trouble.

>-Question on the issue of SelCal auto-powering of TTY motors:
>If you auto on/off with ZCZC and NNNN and if you are dealing with alot of
>traffic, wouldn't that tend to cycle too much?  Would there be a difference
>based on 60/100wpm?

Motor control tied to the SELCAL is a nice feature.  Conventional autostart 
circuits which usually come with motor control are easily tripped by noise 
and off frequency stations resulting in a lot of gibberish and needless 
cycling of the motor and machine.  Normally, there is an adjustable delay 
following the loss of signal and the same would be nice in the SELCAL 
system after the receipt of the NNNN before the circuit turns the motor 
off.  Something on the order of 30 seconds up to a minute to prevent 
frequent cycling, such as in the case as when there is an immediate 
response to a previous message, as you point out.  Without motor control 
from the SELCAL, you would either have to leave the motor on all the time 
or depend on the notoriously undependable autostart motor control offered 
in some TU's autostart circuits.


>My uninformed response:  I dunno -- the radio side of things is not my
>area.  I suppose there could be some delays enforced;  eg: after NNNN, wait
>X seconds or minutes before powering off.
>
>feedback always appreciated,


All I have to say is your "uninformed response"  seems pretty darn informed 
to me, Gil.  You have come up with just a beautiful conceptual design.

Best regards -- Roy Norris, K4EEG


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