[Elecraft] K3S and RTTY Contesting with N1MM+/MMTTY

[Richard Ferch]

There is some confusion evident in your post on the roles of the 
connections between the radio and the computer.

There are three separate connections needed for operation in data modes 
(possibly four in FSK).

The first of these connections is for rig control from N1MM+. On a K3, 
this is the RS232 port. On a K3S, you can use the USB connection 
instead, provided the K3S's CONFIG:RS232 is set for USB. Either way, 
this represents one serial port in the software. N1MM+ must be 
configured to use this port for rig control, and this port cannot be 
used by MMTTY when it is run from within N1MM+. This last limitation 
(inability to share a serial port between the two programs) is why the 
configuration that you use in MMTTY stand-alone does not work when you 
run MMTTY from N1MM+.

The second connection is for audio to and from MMTTY. On a K3, there are 
actually two cables for audio, one in and one out, but on a K3S, these 
can be replaced by a single USB connection to the USB codec inside the 
radio. This happens to be shared with the same USB cable that conveys 
rig control, but there are two separate and independent devices as far 
as the software is concerned - one is a serial port, the other is a 
sound card, and there is no interaction between the two in the 
application software.

This audio connection is used for receive audio, and in AFSK, for 
transmit audio. MMTTY is configured to use the radio's USB codec as its 
sound card; N1MM+ does not need to use the sound card at all in data 
modes (SSB is another story, but I won't go into that here).

The third connection is for TX/RX control, or PTT. There are several 
ways of doing this on the K3/K3S, and it can be controlled either in the 
radio, or in N1MM+, or in MMTTY - pick one.

In AFSK (or in CW), the method internal to the radio is VOX. If you use 
VOX, you do not need to, and for the sake of avoiding confusion you 
should not, configure any other method of PTT either in N1MM+ or in 
MMTTY. However, VOX does not work in FSK D. If the radio is in FSK D, 
PTT must be controlled some other way (either via radio command or via a 
hardware PTT connection).

A second method is to use software radio commands from N1MM+ over the 
radio control line to control PTT. This method can be used by MMTTY when 
it is run stand-alone, but it is not available to MMTTY when it is run 
from within N1MM+ because of the inability to share the port. If you use 
this method, you do not need either a hardware connection or VOX.

A third method is to use serial port keying, by convention usually done 
on RTS, although it is possible to use DTR. In most radios, this has to 
be a separate port from the radio control port, and it has to be through 
a keying circuit. The K3 and K3S are exceptions - you can use RTS on the 
radio control port without any keying circuitry by setting 
CONFIG:PTT-KEY to RTS-OFF (or RTS-DTR to allow CW keying on DTR). This 
must be done from N1MM+, not from MMTTY, because the radio control port 
cannot be shared between the two programs.

You can also use a different serial port for PTT control, in which case 
it would be connected through a keying circuit to either the PTT IN jack 
or to the ACC connector on the K3/K3S. Since this is a different serial 
port from the radio control port, you can choose to use it either from 
N1MM+ or from MMTTY.

The fourth possible connection (which may be shared with the third PTT 
method) is for FSK keying from MMTTY, which is applied via the ACC 
connector. This can be done from a serial port through a keying circuit, 
but it must be a different serial port from the one used for rig 
control. This is a hardware limitation, not just software. The FSK 
serial port must be configured in MMTTY, and there is normally no need 
to mention it at all in N1MM+. MMTTY can also use this same port for PTT 
control, in which case you do not need to configure a PTT method in N1MM+.

It is possible to configure a serial port used by MMTTY in N1MM+ in such 
a way that N1MM+ only uses it in CW/SSB and hands it over to MMTTY in 
data modes, but this is only necessary if you need to time-share the FSK 
port with other uses in other modes, or if you want to use FSK with the 
built-in MMVARI engine in N1MM+.

There is another way to do FSK, and that is via radio control commands 
embedded in CAT1ASC macros in N1MM+, but this method is not supported by 
the N1MM+ programming team, i.e. you are on your own if you try it.

There is no TCP/IP connection to the radio. HRD may use TCP/IP for 
intercommunication between its software modules, but the K3 or K3S has 
no Ethernet connection and no way to use TCP/IP.

Bottom line: You may use VOX in AFSK if you choose to do so, but it is 
not necessary if you have correctly configured one of the other PTT 
control methods.

73,
Rich VE3KI


KD3TB wrote:

> I have a new K3S radio that uses the new  USB for Sound and Radio Control.
> For RTTY contesting I use N1MM+ with the MMTTY interface.  Since the USB
> Codec control appears to act differently than a standard serial port, I need
> to put the Radio in VOX to key RTTY in N1MM+.  In the past with my older K3
> which used a standard Serial port connection, I did not have to do this.  My
> K3 Settings are: Tx Data Mode (AFSK A), with PTT-KEY in rts-dtr . No
> difference in Safe versus unsafe modes. It also requires the VOX on in FSK
> mode too. When I use must MMTTY by itself, I can key with the correct Com
> port.  I am sure this has something to do with how N1MM+ interfaces with the
> new K3S USB Codec . I have not tried this with other RTTY programs such as
> FLdigi, etc.  Everything works fine in CW, DVR Memory keying with the
> correct codes, etc.
>
>
>
> With Ham Radio Deluxe, since it uses a TC/IP connection between the software
> and radio, I do not need to have TX Data in VOX on mode.
>
>
>
> I am not sure to eliminate the requirement for VOX on, if it requires an
> update in either K3S firmware or how N1MM+ interfaces with the K3S USB Codec
> commands. -  Or we just stay with VOX on when contesting.
>
>
>
> Food for thought and what are others experience with the K3S and N1MM+/MMTTY
> in RTTY contesting?