AFSK on K3

[N4BP]

I'm unable to transmit an AFSK signal in DATA mode, although I can transmit RTTY in LSB mode.  The line output from my computer soundcard does have the audio signal on it and is connected to the Line In mono jack on the K3.  For MIC SEL in configuration, I have Line In selected.  DATA MD is set to AFSK A and shows 45 bps.  PITCH is set to 2125-170.  Using MMTTY software barefoot which works properly with my FT-1000MP  (same cable, but new phone plug connectors to mate with K3).  K3 goes into transmit mode and audio signal is present on cable feeding K3's Line In, but no modulation.  What am I missing??

[Ed K1EP]

Bob-
Make sure you have the latest firmware.  Up until the recent release
there were problems with the Line In.  One problem was that although
you had Line In selected, it really wasn't selected unless you went
in to the menu and selected another input and the re-selected Line
In.  I would try that to see if that is the problem.  I had that
problem when using basic LSB or USB modes with Line In.

At 12/24/2007 01:53 PM, N4BP wrote:

>I'm unable to transmit an AFSK signal in DATA mode, although I can transmit
>RTTY in LSB mode.  The line output from my computer soundcard does have the
>audio signal on it and is connected to the Line In mono jack on the K3.  For
>MIC SEL in configuration, I have Line In selected.  DATA MD is set to AFSK A
>and shows 45 bps.  PITCH is set to 2125-170.  Using MMTTY software barefoot
>which works properly with my FT-1000MP  (same cable, but new phone plug
>connectors to mate with K3).  K3 goes into transmit mode and audio signal is
>present on cable feeding K3's Line In, but no modulation.  What am I
>missing??

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[N4BP]

<quote author="Ed K1EP">
Make sure you have the latest firmware.  Up until the recent release
there were problems with the Line In.  One problem was that although
you had Line In selected, it really wasn't selected unless you went
in to the menu and selected another input and the re-selected Line
In.  I would try that to see if that is the problem.  I had that
problem when using basic LSB or USB modes with Line In.

Thanks Ed but, yes I do have the latest firmware.  And the MIC SEL had been changed several times between rP.H (for SSB) and Line In (for AFSK).  Again, the Line In selection works if I transmit AFSK in LSB mode.  But no modulation when in DATA mode.

[KK7P]

> Thanks Ed but, yes I do have the latest firmware.  And the MIC SEL had been
> changed several times between rP.H (for SSB) and Line In (for AFSK).  Again,
> the Line In selection works if I transmit AFSK in LSB mode.  But no
> modulation when in DATA mode.

I just ran some tests here.  The K3 data modes called DATA A and DATA A
REV are working in transmit with LINE IN and should work with any
soundcard mode, including AFSK.  The K3 data mode called AFSK appears to
not be working properly in transmit.

73,

Lyle KK7P



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[N4BP]

<quote author="Lyle Johnson-6">
I just ran some tests here.  The K3 data modes called DATA A and DATA A
REV are working in transmit with LINE IN and should work with any
soundcard mode, including AFSK.  The K3 data mode called AFSK appears to
not be working properly in transmit.

Unfortunately, DATA A doesn't work very well for receiving RTTY.  The SHIFT has to be set to the upper limit - which still doesn't reach the center of the passband - and width can't be used below about 450 cycles.  Also, DUAL PB is not usable.  AFSK A works perfectly for receive.  Now if only it worked for transmit..
My hope is that this will be fixed in a firmware revision before the ARRL RTTY Roundup on January 5/6???

[rkayakr]

The AFSK mode has an undocumented INPUT filter limiting Line In signal from 800 to 1200 Hz. You can get a signal out in that range and you can set the pitch to 915 MHz for receive. Unfortunately, invoking the Dual PB filter inhibits transmission in AFSK, so you might as well use DATA A, where Dual PB also doesn't work (stops all received signals).

The Line IN problem has apparently not been fixed, results remain inconsistent. Another gotya is that having CWT on inhibits transmission.

Elecraft support says that these are all known problems.

    Bob
       KD8CGH
          KX1, K2, K3