[Elecraft] RTTY using DATA mode on K3

[Derek Cohn/WB0TUA]

Hi Everyone,

I just bought a K3 a few weeks ago and have been using it on CW. It's time to play with it a bit on RTTY. I'm using the Tigetronics Signalink to interface the radio to my PC which is running MMTTY. When I have the mode switch in the sideband position, copy on the laptop is just fine and the signals display properly on the tuning aids in MMTTY. I read the manual pages about better performance if the DATA mode is selected. I switched to the DATA mode and there is very little audio in the speaker and no signals displayed on the tuning aids in MMTTY. No copy either. I double-checked the data mode setting and it is AFSK-A which I think is correct. I must have a setting wrong somewhere. I've gone over the data section in the manual a few more times but don't see what I'm doing wrong. Any ideas?

Thanks and 73,

Derek Cohn
Morse Telegraph Club - Alton Chapter
Office UD, Sine DJ
Amateur Radio Station - WBØTUA
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[Richard Ferch]

WB0TUA wrote:

> I just bought a K3 a few weeks ago and have been using it on CW. It's time to play \
> with it a bit on RTTY. I'm using the Tigetronics Signalink to interface the radio to \
> my PC which is running MMTTY. When I have the mode switch in the sideband position, \
> copy on the laptop is just fine and the signals display properly on the tuning aids \
> in MMTTY. I read the manual pages about better performance if the DATA mode is \
> selected. I switched to the DATA mode and there is very little audio in the speaker \
> and no signals displayed on the tuning aids in MMTTY. No copy either. I \
> double-checked the data mode setting and it is AFSK-A which I think is correct. I \
> must have a setting wrong somewhere. I've gone over the data section in the manual a \
> few more times but don't see what I'm doing wrong. Any ideas?

Derek,

I wouldn't have said that DATA modes give you better performance
necessarily, but using AFSK A gives you the ability to use a number of
RTTY-specific features on the K3 that are not available in SSB mode.

In AFSK A, the default filter settings are much narrower than in LSB, so
you don't have as much freedom to tune signals using an arbitrary audio
frequency. Check that the PITCH setting on the K3 in AFSK A mode is
consistent with the Mark setting in MMTTY, and that when you tune in a
signal you tune such that the received audio mark tone lands on that
audio frequency. To start with, I'd suggest that you turn MMTTY's AFC
off, and use the K3's tuning knob to tune in signals - don't click with
the mouse in the waterfall or let AFC tune to nearby signals.

73,
Rich VE3KI

[Wes Stewart]

I'm using the same setup.

Check the K3 pitch (Hold the "Spot" button) and verify that it's the same as the Mark setting in MMTTY.  I used 915 Hz since it's much easier on the ears and I can almost tune signals by ear now close enough to demodulate.  The downside to the lower tone is the possibility of more IMD on transmit.

Turn off Net and AFC.  I tune the K3 frequency using the MMTTY X-Y display.  (If I could turn off the waterfall I would.)

Wes  N7WS

--- On Sun, 4/18/10, Derek Cohn/WB0TUA <vibr...@mindspring.com> wrote:

> From: Derek Cohn/WB0TUA <vibr...@mindspring.com>
> Subject: [Elecraft] RTTY using DATA mode on K3
> To: elec...@mailman.qth.net
> Date: Sunday, April 18, 2010, 9:53 AM
> Hi Everyone,
>
> I just bought a K3 a few weeks ago and have been using it
> on CW.  It's time to play with it a bit on RTTY. 
> I'm using the Tigetronics Signalink to interface the radio
> to my PC which is running MMTTY.  When I have the mode
> switch in the sideband position, copy on the laptop is just
> fine and the signals display properly on the tuning aids in
> MMTTY.  I read the manual pages about better
> performance if the DATA mode is selected.  I switched
> to the DATA mode and there is very little audio in the
> speaker and no signals displayed on the tuning aids in
> MMTTY.  No copy either.  I double-checked the data
> mode setting and it is AFSK-A which I think is
> correct.  I must have a setting wrong somewhere. 
> I've gone over the data section in the manual a few more
> times but don't see what I'm doing wrong.  Any ideas?
>

> Thanks and 73,
>
> Derek Cohn
> Morse Telegraph Club - Alton Chapter
> Office UD, Sine DJ
> Amateur Radio Station - WBØTUA

[Bill VanAlstyne W5WVO]

Hi Derek,

When using a computer and sound card to drive the K3 in any digital mode,
your data mode should be set to DATA A. Somebody will correct me if I'm
wrong, but I suspect that's your problem.

DATA A mode is basically equivalent to the USB/LSB position, except that
equalization and compression are disabled.

Bill W5VWO


--------------------------------------------------
From: "Derek Cohn/WB0TUA" <vibr...@mindspring.com>
Sent: Sunday, April 18, 2010 9:53 AM
To: <elec...@mailman.qth.net>

Subject: [Elecraft] RTTY using DATA mode on K3

[Bill VanAlstyne W5WVO]

Looks like I am off-base here. Please disregard my post, Derek.
Bill W5VWO

--------------------------------------------------
From: "Bill VanAlstyne W5WVO" <w5...@cybermesa.net>
Sent: Sunday, April 18, 2010 12:27 PM
To: "Derek Cohn/WB0TUA" <vibr...@mindspring.com>;
<elec...@mailman.qth.net>
Subject: Re: [Elecraft] RTTY using DATA mode on K3

[Gary Hinson]

Something that caught me out once or twice is that the PC's audio output should be close to the K3's
tone settings on RTTy (can't remember if this is DATA or AFSK modes - possibly both). With MMTTY,
it's possible to net the TX tones to the RX tones anywhere on the watefall, but if the TX tones are
way off the rig's expected tone frequencies, they are filtered away. [This is even without any TX
equalization.]

73
Gary ZL2iFB

[Mike Harris]

G'day,

My AFSK A pitch is set to 1445Hz. MMTTY (in Logger32) is set to
default to 1445Hz.

When I start up MMTTY the frequency markers on the waterfall are
appropriate for 1445Hz paired tones. If I activate the DUAL PB
filter the filter is also matched to the tone pair.

If I change the K3 pitch setting then the DUAL PB filter changes to
the new pitch frequency pair.

Without DUAL PB activated I can receive and transmit anywhere within
the displayed waterfall, dependent upon the IF bandwidth selected
simply by clicking on the desired signal.

With DUAL PB activated I can only receive at the pitch frequency
pair and tuning to a new signal requires use of the VFO. As
expected.

With NET ON the MMTTY TX tones follow the RX setting, with NET OFF
the TX tones remain fixed to the MMTTY pitch setting, in may case
1445Hz and the receive can be anywhere in the waterfall. This is
naturally how one can work narrow split or answers callers off
frequency, or at least I do.

Now, there is a catch if you have CONFIG: AFSK TX - FIL ON. The K3
wraps a 400Hz DSP TX filter around the selected TX pitch pair. If
you then try and TX anywhere outside that 400Hz filter there is no
output. Like the DUAL PB this filter is shifted to match the K3
pitch setting. The default setting is OFF.

In AFSK A mode the K3 displays the RTTY Mark frequency which means
when I click on a spot the radio is tuned to the spot. This will
not happen if you use DATA A, you have to offset the VFO manually to
go looking for the signal in the waterfall.

For what it's worth. Oh yes, it's all in the handbook!

Regards,

Mike VP8NO