I haven't even gotten started in comparing filters yet. In the next RTTY
contest, I will record the incoming audio stream on a HI-FI VCR and will
use a playback to several decoders after the contest to compare different
modes/parameters. MMTTY is a neat program for anybody who wants to "tweak
the knobs".
Jerry W4UK
At 10:53 AM 2/21/01 -0800, you wrote:
>Was the effort worth it? Have you noticed an improvement in copying?
>
>Steve
>W1SRD
>
>> -----Original Message-----
>> From: owner-writelog@contesting.com
>> [mailto:owner-writelog@contesting.com]On Behalf Of Jerry Flanders
>> Sent: Monday, February 19, 2001 9:51 AM
>> To: MMTTY@yahoogroups.com
>> Cc: writelog@contesting.com
>> Subject: [WriteLog] Two sound cards, two copies of MMTTY simultaneously
>>
>>
>>
>> I have installed an additional sound card in a minimal Win98se
>> computer. My
>> goal was to run two copies of MMTTY simultaneously to compare various
>> filter mode/parameter combinations.
>>
>> I have read on the newsgroups that it is difficult to get two sound cards
>> running simultaneously, so approached this with a bit of fear. But the
>> sound card was inexpensive, so not much to lose if it didn't work.
>>
>> It works! After some initially confusing results, all seems to work now. I
>> am running two independent copies of MMTTY on the (150PR Cyrix 6x86)
>> machine right now, using different demodulator parameters, from the two
>> independent soundcards, and each copy is getting its input audio stream
>> from the proper input line jack. I don't see any performance
>> degradation of
>> any kind yet, with one copy running FIR and the other IIR, both with
>> "normal" parameters.
>>
>> Yippee!
>>
>> The new sound card was a $20 (regular price) cheapie from CompUSA with
>> ALS-4000 guts. The install was the automatic PnP install under
>> Win98se, and
>> followed an automatic install of the original (also a cheapie, but
>> different) card. All interrupts were already in use on this machine, so
>> some are being shared now. I may have to change interrupts manually later
>> if conflicts arise in use.
>>
>> I set the volume on each card independently - calling up the "master
>> volume" panel allows me to select which card to adjust. This is a little
>> cumbersome, but is not needed often.
>>
>> One copy of MMTTY is using sound device 0, the other is using 1.
>>
>> This computer will be dedicated as a receive-only dumb terminal
>> demodulator. It will eventually pass the decoded outputs through
>> the serial
>> ports to a second computer running WriteLog. I hope to use the second
>> decoded RTTY stream initially to run a routine RTTY filter and a flutter
>> filter simultaneously and later provide both demods for two-radio
>> contesting.
>>
>>
>> Jerry W4UK
>>
>>
>>
>>
>> --
>> WWW: http://www.writelog.com/
>> Submissions: writelog@contesting.com
>> Administrative requests: writelog-REQUEST@contesting.com
>> Problems: owner-writelog@contesting.com
>>
>>
>
>
>
--
WWW: http://www.writelog.com/
Submissions: writelog@contesting.com
Administrative requests: writelog-REQUEST@contesting.com
Problems: owner-writelog@contesting.com
|