The introduction of intercharacter delays would definitely change the
throughput while not altering the timing a bit.
Al
AB2ZY
-----Original Message-----
From: rtty-bounces@contesting.com [mailto:rtty-bounces@contesting.com] On
Behalf Of Don Hill AA5AU
Sent: Monday, March 21, 2011 9:07 PM
To: rtty@contesting.com
Subject: Re: [RTTY] RTTY
In MMTTY, there is both a "Character wait" and "Diddle wait" which make your
transmission go out slower. In the TX tab of MMTTY Setup, there is a check box
for "Disable Wait". If it is not checked, then MMTTY uses the values as set in
the two slider bars for character wait and diddle wait. Testing in FSK,
revealed that indeed both of these slider settings change the "speed" at which
the "characters" or "diddles" are sent. With both sliders all the way to the
left, it appears is the same as checking the "Disable Wait" check box. As you
move either slider to the right, the "speed" appears slower even though it's
still decoded at 45.45 baud.
Here's what the MMTTY help file says:
"Transmit Wait Adjustment
There is a transmit wait, or delay, control, that appears by default as "Both
Wait" at the far right of the transmit menu. The slider to the right controls
the amount of time (wait) between transmission of characters. Select one of
four values by clicking the label.
Disable wait - Slider position does not matter, there is no wait.
Char. wait - Delay character transmission.
Diddle wait - Delay diddle character transmission.
Both wait - Delay both character and diddle transmission. "
I don't see a "Both wait" option in version 1.68 so maybe that was left over
from a previous version. Elsewhere in the help file it says something about
using "wait" if there is a problem on a slower computer. I doubt anyone would
have a problem these days and everyone should disable wait.
73, Don AA5AU
http://www.aa5au.com
http://www.rttycontesting.com
-----Original Message-----
From: rtty-bounces@contesting.com [mailto:rtty-bounces@contesting.com] On
Behalf Of Al Kozakiewicz
Sent: Monday, March 21, 2011 7:11 PM
To: 'Ktfrog007@aol.com'; rtty@contesting.com
Subject: Re: [RTTY] RTTY
>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@contesting.com [mailto:rtty-bounces@contesting.com] On
Behalf Of Ktfrog007@aol.com
Sent: Monday, March 21, 2011 7:51 PM
To: rtty@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
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