Oh... and by the way... while searching I found this interesting tidbit at
the bottom of this page: http://rtty_rangers.rdxa.com/RTTY_Rangers_3.htm
! The first cash register was invented by James Ritty following the
American Civil War. He was the owner of a saloon in Dayton, Ohio, USA, and
wanted to stop employees from pilfering his profits. He invented the Ritty
Model I in 1879 after seeing a tool that counted the revolutions of the
propeller on a steamship. With the help of John Ritty, his brother, he
patented it in 1883. Shortly thereafter, Ritty became overwhelmed with
the responsibilities of running two businesses, so he sold all of his
interests in the cash register business to Jacob H. Eckert of Cincinnati, a
china and glassware salesman, who formed the National Manufacturing
Company. In 1884 Eckert sold the company to John H. Patterson, who renamed
the company the National Cash Register Company and improved the cash
register by adding a paper roll to record sales transactions, thereby
creating the receipt. In 1906, while working at the National Cash
Register company, inventor Charles F. Kettering designed a cash register
with an electric motor.
----- Original Message -----
From: "Robert Chudek - K0RC" <k0rc@citlink.net>
To: <n7us@arrl.net>; <rtty@contesting.com>
Sent: Thursday, September 17, 2009 10:06 AM
Subject: Re: [RTTY] Sound Cards and Software
GM Jim,
I wasn't aware of the survey you posted so thanks for that link!
I did a quick search and could not find a reference to the discussion /
article I am thinking about. It might have been in conjunction with sound
card testing for SDR purposes although I do recall specific mention about
RTTY decoding showing minimal improvement across the whole spectrum of audio
cards being tested. What I recall is this was one person who tested a
handful of cards in a more-or-less lab environment using test equipment.
I'll continue to search and hopefully I can find the source of my
recollection. Or maybe someone else recalls the comparison I'm thinking
about and will comment or post a link.
73 de Bob - KØRC in MN
----- Original Message -----
From: "Jim N7US" <n7us@arrl.net>
To: <rtty@contesting.com>
Sent: Thursday, September 17, 2009 5:03 AM
Subject: Re: [RTTY] Sound Cards and Software
The soundcard survey was way back in 2001:
http://www.qsl.net/wa9als/sound_results.htm
Jim N7US
-----Original Message-----
Bill,
A few years ago "someone" (sorry I don't recall who it was) ran tests on a
variety of soundcards, from cheap $20 cards to high-end $200+ cards. The
result was for RTTY use, there wasn't a significant difference in
performance among all the cards tested. That is not to say the expensive
cards couldn't do more, it was simply that our RTTY decoding needs did not
take advantage of the high-end features. The conclusion was to save your
money and put it toward a second decoder and run it in parallel.
Other fellows have run comparisons between MMTTY and other decoders, and
specifically high-end standalone units like the HAL products. MMTTY always
compares favorably to other decoders. The performance difference is always
small, but the edge will sometimes go to the external unit. Overall, the
MMTTY decoder continues to be near the top of the list of "state of the art"
decoders, even though it was developed a decade ago.
Another software decoder that is a strong performer is RITTY by K6STI. Many
contesters continue to use this soundcard based software even though it is a
DOS based decoder. I don't think you can buy it anymore. It was taken off
the market after copyright violations were discovered by its author. This
was a terrible loss of creative talent for the Amateur Radio community
perpetrated by some individuals who thought pirating software was an
acceptable activity.
Regarding "noise" around your ellipsis on the MMTTY display, this is normal
bandnoise. If you select the FIR decoder the software will provide a crisp +
(plus) symbol when a station is tuned in properly. This display will also
have random noise although to a lesser degree.
73 de Bob - KØRC in MN
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