[RTTY] Affordable PCI sound card recommendations?

Thu Feb 5 09:34:58 EST 2009

Simply un select the internal mic in the mixer used for sound card settings.

73
Jim W7RY

----- Original Message ----- 
From: <Gedking at aol.com>
To: <k0rc at citlink.net>; <rtty at contesting.com>
Sent: Thursday, February 05, 2009 5:46 AM
Subject: Re: [RTTY] Affordable PCI sound card recommendations?

>I sometimes use my little dell laptop on another rig and it picks up 
>outside
> noises and even picked up the sound from my other rig and decoded it. I 
> been
> looking for the built in Mic but can't find it. No big thing but it bugs 
> me
> ED K8OT
>
>
> In a message dated 2/5/2009 12:58:33 A.M. Eastern Standard Time,
> k0rc at citlink.net writes:
>
> There's  other things to consider beyond the soundcard. The soundcard is
> usually on  the bottom of my suspect list.
>
> In MMTTY you can select from three  different demodulators by clicking the
> TYPE button. Above and slightly to  the left of this button will be the
> acronyms FIR, IIR, and PLL as you  click through them. Depending upon band
> conditions at the moment, one of  the three can provide better copy.
>
> Something beyond operator control is  band and path conditions. It's 
> possible
> to have a S-9 signal and not be  able to decode because of bit distortion
> (delay). This is especially  prevalent on signals going over a polar path.
>
> Another issue can be AC  hum (ground loop). A few months back I 
> experienced
> this for the first time  in my shack. I saw the ripple on the scope. It 
> just
> didn't "look right"  and MMTTY wasn't decoding for beans. I figured out 
> the
> problem but I don't  recall what I did at the moment.
>
> The difference between copy and no  copy is rig dependant too. I was not a
> believer until I bought an Icom 756  Pro III and turned on the RTTY twin 
> peak
> filter. It brought signals out of  the noise the I would never been able 
> to
> copy on my TS-950SDX... even with  all of it's filters and DSP.
>
> Another source of "self inflicted QRM" can  be your own monitoring system. 
> If
> you are picking your RX audio from the  external speaker, it (the
> loudspeaker) will pickup room noises (another  RTTY signal from a 
> different
> radio perhaps?) and feed that into your  soundcard input. Now you have two
> competing signals going into the MMTTY  decoder.
>
> Just a few thoughts.
>
> 73 de Bob - KØRC in  MN
>
>
> ----- Original Message ----- 
> From: "Iain MacDonnell - N6ML"  <ar at dseven.org>
> To: "Robert Chudek - K0RC"  <k0rc at citlink.net>
> Cc: <RTTY at contesting.com>
> Sent:  Wednesday, February 04, 2009 10:36 PM
> Subject: Re: [RTTY] Affordable PCI  sound card recommendations?
>
>
>>
>> Hi Bob,
>>
>>  The problem was that weaker signals were not decoding (cleanly). It's
>>  difficult to quantify, but judging by ear, the signals should have  been
>> strong enough to fully copy. Changing from the on-board - most  likely
>> AC97-based (I'm not at the site now) - interface to a couple  of
>> different USB devices (an EMU-0202 and a Griffin iMic2) cleared  the
>> problem right up - those weaker signals started decoding just  fine.
>>
>> I think I'm going to go for something in the sound  blaster line. I'd
>> like to have something that does most of the work in  hardware, rather
>> than a software codec - it just seems like that might  be more reliable.
>>
>> Thanks for the input... and for Qs in a  bunch of recent contests :)
>>
>>     ~Iain /  N6ML
>>
>>
>>
>> Robert Chudek - K0RC wrote:
>>>  "We've tried the on-board audio with MMTTY, and had major problems
>>> decoding."
>>>
>>> What were the major problems  you experienced decoding?
>>>
>>> To answer you question,  virtually any soundcard will provide good
>>> results. The SB Live!  series work well.
>>>
>>> 73 de Bob - KØRC in  MN
>>>
>>>
>>> ----- Original Message ----- From:  "Iain MacDonnell - N6ML"
>>> <ar at dseven.org>
>>> To:  <RTTY at contesting.com>
>>> Sent: Wednesday, February 04, 2009  9:38 PM
>>> Subject: [RTTY] Affordable PCI sound card  recommendations?
>>>
>>>
>>>>
>>>> I  need to outfit a number of WinXP PCs at a contest station for
>>>>  RTTY. We've tried the on-board audio with MMTTY, and had major
>>>>  problems decoding. I got around this for the last contest (RU)
>>>>  by using external USB audio interfaces, but want to install
>>>>  something internal in each PC to make it permanent. I've seen
>>>>  a number of Sound Blaster Live! options on eBay in the order
>>>>  of $10-15 shipped, but thought I'd ask here if there are any
>>>>  particular models that work well, or are known to not work  well
>>>> for RTTY decoding (and maybe AFSK transmit  too).
>>>>
>>>> TIA for any  recommendations...
>>>>
>>>>     ~Iain /  N6ML
>>>>
>>>>
>>>>  _______________________________________________
>>>> RTTY mailing  list
>>>> RTTY at contesting.com
>>>>  http://lists.contesting.com/mailman/listinfo/rtty
>>>>
>>>
>>
>
> _______________________________________________
> RTTY mailing  list
> RTTY at contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty
>
> **************Great Deals on Dell Laptops. Starting at $499.
> (http://pr.atwola.com/promoclk/100000075x1217883258x1201191827/aol?redir=http://ad.doubleclick.
> net/clk;211531132;33070124;e)
> _______________________________________________
> RTTY mailing list
> RTTY at contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty
>

--------------------------------------------------------------------------------

No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.0.233 / Virus Database: 270.10.16/1929 - Release Date: 01/30/09 
17:31:00