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K-3: USB SignaLink for better RTTY decoding?

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RLVZ

K-3: USB SignaLink for better RTTY decoding?

Hi Guys,

I really like the K-3 for RTTY. But I'm trying to maximize reception as
during contests I often hear stations calling me that I can't copy. I
believe the weakest link with my RTTY reception is the SoundCard in my current
Desktop. I say this because I use a different Desktop while operating from
my Midwest QTH and that computer seems to decode weak signals with the same
K-3 a lot better. Funny thing is that the processor in that Desktop that
decodes better is about 50% slower. So my question is: do you thinking
replacing my current Desktop's SoundCard with a USB SignaLink would improve
weak signal RTTY reception? Note: I have done various routines to calibrate
the Desktop Sound Card with little improvement.

Thanks & 73,

Dick- K9OM
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Lorenz Koestler

Re: K-3: USB SignaLink for better RTTY decoding?

Hi Dick

I haven't much experiance with RTTY on different soundcards. But I
noticed that the SignaLink interface is much better (lesser noise) then
most integrated sound cards. Especially compared to the sound cards in
notebooks.

One point is the galvanic isolation. But I think the biggest advantage
of a SignaLink interface is the usability. The potentiometer are very
useful to ajust the levels. Our local distributor in Switzerland ships
the interface together with all cables needed for the K3.

best 73 de Lorenz / HB9TYU

On 02/24/2011 03:39 AM, [hidden email] wrote:

>
> Hi Guys,
>
> I really like the K-3 for RTTY. But I'm trying to maximize reception as
> during contests I often hear stations calling me that I can't copy. I
> believe the weakest link with my RTTY reception is the SoundCard in my current
> Desktop. I say this because I use a different Desktop while operating from
> my Midwest QTH and that computer seems to decode weak signals with the same
> K-3 a lot better. Funny thing is that the processor in that Desktop that
> decodes better is about 50% slower. So my question is: do you thinking
> replacing my current Desktop's SoundCard with a USB SignaLink would improve
> weak signal RTTY reception? Note: I have done various routines to calibrate
> the Desktop Sound Card with little improvement.
>
> Thanks& 73,
>
> Dick- K9OM
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

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KD8NNU

Re: K-3: USB SignaLink for better RTTY decoding?

In reply to this post by RLVZ

Interesting question as I use a laptop right now with and internal sound
card and if I can see the trace the DM780 will decode it unless there
are strong signals close by. Then I tighten the filters down and
usually it comes in clean.

Maybe the number of bits in the sound card make a big difference but I
dont know how to check this.

Also what filters do you use, I am on the fence regarding a 500 hz or
700 hxz 8 pole to add to the system.

Don
KD8NNU

On Thu, Feb 24, 2011 at 3:39 AM, [hidden email] wrote:

> Hi Guys,
> I really like the K-3 for RTTY. But I'm trying to maximize
> reception as during contests I often hear stations calling me that I
> can't copy. I believe the weakest link with my RTTY reception is the
> SoundCard in my current Desktop. I say this because I use a
> different Desktop while operating from my Midwest QTH and that
> computer seems to decode weak signals with the same K-3 a lot better.
> Funny thing is that the processor in that Desktop that decodes better
> is about 50% slower. So my question is: do you thinking replacing my
> current Desktop's SoundCard with a USB SignaLink would improve weak
> signal RTTY reception? Note: I have done various routines to
> calibrate the Desktop Sound Card with little improvement.
> Thanks & 73,
> Dick- K9OM
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Julian, G4ILO

Re: K-3: USB SignaLink for better RTTY decoding?

I use digital modes quite a lot and I think the factor that makes the biggest difference with the ability to copy correctly is the sound card clock accuracy which affects the baud rate. With some of the cheaper sound cards the clock rate when 11025Hz is selected may be 11050Hz or even 11100Hz. This can make all the difference between decoding a mode like Olivia or 1200baud packet and not decoding it. I wouldn't have thought RTTY being a slower mode was as sensitive but I don't use RTTY so I can't say one way or another.

One thing you could do is use the built-in RTTY decoder in the K3. KComm supports it.

Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com
* KComm - http://www.g4ilo.com/kcomm.html
* KTune - http://www.g4ilo.com/ktune.html

N7US

Re: K-3: USB SignaLink for better RTTY decoding?

In reply to this post by RLVZ

Dick,

If I were starting from scratch, I'd get a microKEYER II
(http://www.microham-usa.com/) because of the integration it offers,
including a second FSK port for SO2V operation with the K3, SteppIR control,
etc., all from one USB port, and the support from Joe, W4TV. The K3 has the
isolation on the audio ports, but the choice depends the total package of
features that you want.

I haven't done that yet, but I did get one of the external USB sound boxes
that W4TV mentioned on the RTTY reflector. It's now $6 cheaper at only
$18.99 than what I paid a couple of months ago:

http://www.newegg.com/Product/Product.aspx?Item=N82E16829180006

I found it to require less drive than the fancy sound card built into my
Dell computer. I'm still using FSK with a simple HB interface at
http://www.aa5au.com/rttyinterface.html . I believe that the SignaLink uses
AFSK for transmit, but I prefer FSK.

I use the left and right receiver channels to decode the main receiver and
subreceiver, respectively, in split frequency DX pileups, using two
instances of MMTTY. The USB sound box does fine for that too.

Jim N7US

-----Original Message-----

Hi Guys,

I really like the K-3 for RTTY. But I'm trying to maximize reception as
during contests I often hear stations calling me that I can't copy. I
believe the weakest link with my RTTY reception is the SoundCard in my
current
Desktop. I say this because I use a different Desktop while operating from

my Midwest QTH and that computer seems to decode weak signals with the same

K-3 a lot better. Funny thing is that the processor in that Desktop that
decodes better is about 50% slower. So my question is: do you thinking
replacing my current Desktop's SoundCard with a USB SignaLink would improve

weak signal RTTY reception? Note: I have done various routines to
calibrate
the Desktop Sound Card with little improvement.

Thanks & 73,

Dick- K9OM

______________________________________________________________
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n7ws

Re: K-3: USB SignaLink for better RTTY decoding?

In reply to this post by RLVZ

I have used a Signalink with my K3 with good results. I have cables (and headers) for both the K3 and my Kenwood TS-870 and have used it with both radios. However, when I added a SDR-IQ as a panadapter to the K3 I ran out of USB ports on my laptop and went to a straight connection from the K3 Line In/Out to the built-in sound card on the Lenovo T400 laptop. (I use a second monitor for more screen real estate) Performance has been acceptable but I have not done an A/B comparison with two instances of MMTTY running. The Signalink might be better (or worse) but I can't say.

In the K3 I have the 400 Hz, 8-pole filter and usually use a 200 Hz DSP BW without the dual peak turned on.

The Signalink is AFSK only and to use the better FSK filtering in my Kenwood, I have built a prototype FSK decoder board that decodes the Signalink AFSK signal to a digital signal for direct FSK transmit. I was well on the way to committing this to a PC board that would install inside the Signalink case, but my lovely wife passed away early last month and I've lost all interest in this project (and a lot of other things).

In testing the FSK board I've used the K3 as the receiver and can say that the K3 internal RTTY decoder is very poor compared to MMTTY using the laptop soundcard.

Wes N7WS

--- On Wed, 2/23/11, [hidden email] <[hidden email]> wrote:

>
> Hi Guys,
>
> I really like the K-3 for RTTY. But I'm trying to
> maximize reception as
> during contests I often hear stations calling me that I
> can't copy. I
> believe the weakest link with my RTTY reception is
> the SoundCard in my current
> Desktop. I say this because I use a different
> Desktop while operating from
> my Midwest QTH and that computer seems to decode weak
> signals with the same
> K-3 a lot better. Funny thing is that the
> processor in that Desktop that
> decodes better is about 50% slower. So my question
> is: do you thinking
> replacing my current Desktop's SoundCard with a USB
> SignaLink would improve
> weak signal RTTY reception? Note: I have done
> various routines to calibrate
> the Desktop Sound Card with little improvement.
>
> Thanks & 73,
>
> Dick- K9OM