FWIW, I have fun into issues with some on-board audio devices, where
it seemed like weaker signals were not decoding (in MMTTY) when it
seemed like they should be copyable. Changing to a USB sound card was
a quick fix, and those weaker signals started decoding fine. I often
use an inexpensive Griffin iMic2. I've had good experience with Sound
Blaster Live! PCI cards, which can be picked up (used) on eBay quite
inexpensively, although there does seem to be an issue with Sound
Blaster cards when connecting more than one MMTTY to the same device
at the same time, where the input level seems to get "out of whack"
("overload" in MMTTY). One might want to run multiple MMTTY instances
simultaneously, using different decoder profiles.
I don't have any scientific explanations for any of the above - just
practical experience...
~Iain / N6ML
On Wed, Sep 16, 2009 at 12:23 PM, Robert Chudek - K0RC <k0rc@citlink.net> wrote:
> 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
>
>
>
> ----- Original Message -----
> From: "Bill Gaines AD8P" <ad8p@wcoil.com>
> To: <rtty@contesting.com>
> Sent: Monday, September 14, 2009 1:27 PM
> Subject: [RTTY] Sound Cards and Software
>
>
>>I am somewhat new at digital RTTY operating. I seem to long for the oil
>>smelling model 28 and 32 I used to have. However I have voluntarily come to
>>the 21st century and have some questions about what to use.
>>
>> Currently I use an Orion transceiver in FSK mode, Micro Keyer interface,
>> MMTTY for general use and N1MM with MMTTY imbedded for contesting. When
>> tuning I always use the elliptical crosses simply because that is how I
>> learned to do it 40 years ago. However, on and around those crosses I see
>> lots of what I would call noise. Interference of some sort. The elliptical
>> crosses are always much brighter and very easy to see unless the station
>> is pretty weak. Would other software or a different sound card make
>> receiving a weak station better? I am not asking for your opinions on what
>> would operate easier etc because by now teaching this old dog a new trick
>> will be pretty darn hard to do. Just simply, will a better/different sound
>> card or software make me able to hear the weaker ones better?
>>
>> TIA everyone,
>>
>> Bill AD8P
>>
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>
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