[aprssig] Telemetry question

[Andrew Rich]

Scott, There would be no idle times.

So how does RTTY work then ?

My grandfather used to run a PLL on one tone and anything else was the other
tone.


----- Original Message -----
From: <scott at opentrac.org>
To: "'Andrew Rich'" <vk4tec at hotmail.com>; "'TAPR APRS Mailing List'"
<aprssig at lists.tapr.org>
Sent: Sunday, August 15, 2004 3:14 AM
Subject: RE: [aprssig] Telemetry question


See the bit here on Asynchronous vs. Synchronous transmission:

http://www.camiresearch.com/Data_Com_Basics/data_com_tutorial.html#anchor418
474

AX.25 uses bit-stuffing to make sure there are always enough transitions to
keep the receiver synchronized.  Idle periods of any length will cause the
receiver and transmitter to lose sync, and you'll need a certain number of
transitions to regain it.  I think you can use a flip-flop to do Manchester
encoding, which should work better... but I wouldn't expect to be able to
feed unprocessed async serial into a MX614 and be able to recover anything
reliably.

Scott
N1VG

-----Original Message-----
From: aprssig-bounces at lists.tapr.org
[mailto:aprssig-bounces at lists.tapr.org]On Behalf Of Andrew Rich
Sent: Saturday, August 14, 2004 1:36 AM
To: TAPR PIC Development Special Interest Group
Cc: TAPR APRS Special Interest Group
Subject: [aprssig] Telemetry question


If I want to send RS232 data across a voice channel, what is stopping me
using MX614 ?

No checksum, not interested, no flags, no ax25 not interested, just wanna
send data.

Comments ?