[RTTY] RTTY

[Al Kozakiewicz]

>What is the effect of the sound card clock adjustment? 

Nothing as far as data transmission/reception is concerned.  With ansynchronous communications. you need a clock at each end running at (in the case of 45.5 baud, close to) the same frequency.  The leading edge of the start bit tells the receiver to start clocking the data bits into individual registers.  The meaningful exchange is over once the agreed upon data and parity bits have been sent. The stop bit(s) are a vestige of  the electro-mechanical days.  They provided a time slot to imprint the character.

If RTTY is "slow", it can only be due to more stop bits being sent in a character than necessary, or very inefficient shifting.  It's not due to the sender's bit clock being slow - that would just cause the transmission to be indecipherable.

Al
AB2ZY

-----Original Message-----
From: rtty-bounces at contesting.com [mailto:rtty-bounces at contesting.com] On Behalf Of Ktfrog007 at aol.com
Sent: Monday, March 21, 2011 7:51 PM
To: rtty at contesting.com
Subject: Re: [RTTY] RTTY

Hi Don,
 
What is the effect of the sound card clock adjustment?  Is it related  to speed issues?See Calibrate the Sound Card in the Help file and the Misc tab in MMTTY setup.  I've never understood what it is and what the adjustment does.
 
73,
Kermit, AB1J