[Dx4win] Need some help with MMTTY - SOLVED

[Larry Alkoff]

I previously reported trouble getting a Rigblaster Plus to key FSK using 
the MMTTY engine in DX4Win 7.  It turns out you cannot use both CW 
keying and FSK rtty keying with a Rigblaster Plus because Windows does 
not allow separate programs such as DX4Win and MMTTY to use the same 
serial port.  This is why Rigblaster Pro has 2 serial ports.

The easiest solution was to build a separate two transistor interface 
right into a DB-9 hood with a pigtail connected to the rear Yaesu rtty 
port.  Both FSK and PTT can be done at the rear port.

The interface took _me_ over a day to gather parts, design, build and 
debug but should take _you_ no more than a couple hours.

Below are my design notes.
Hope this information helps someone else.

Larry Alkoff N2LA

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

rttyrat.nfo                     6/28/05

The rttyrat is a simple two NPN transistor interface built into a DB-9 
hood used to key rtty PTT and FSK through the Yaesu rtty jack.

This device is connected to a _different_ serial port than a Rigblaster
type connection to allow rtty to be separately from the
normal Rigblaster PTT and CW keying.

This gets around the Windows problem that two programs
(such as DX4Win and MMTTY) cannot use the same serial port).

FSK is preferable to audio keyed rtty because there is no need to fiddle
with the audio levels to prevent overdriving which causes QRM.
The Yaesu rtty mode through the rear rtty jack allows the use of the 
Yaesu narrow filters

My setup uses com1 for a Rigblaster Plus and com2 for the rttyrat.
If you use a USB derived serial port,  make _sure_ it can support 5 bit 
Baudot code.



      DB-9                                               Yaesu DIN
     ----- 
-------------------
                                          NPN transistor
                                                / col ------> pin 1 FSK
     pin 3 TXD ----- 1k resistor ------  base |/
                                              |\
                                                \
     pin 5 ground  -------------------------- ground -------> pin 4 gnd


                                          NPN transistor
                                                / col ------> pin 3 PTT
     pin 7 RTS ----- 1k resistor ------  base |/
                                              |\
                                                \
     pin 5 ground  -------------------------- ground -------> pin 4 gnd




     Pinout of DB 9                        Pinout of Yaesu rtty DIN jack
     viewed from solder side                     viewed from solder side
     -----------                            -----------------------------

          1 2 3 4 5                                      2   3
           6 7 8 9                                      1     4

           3=TXD                                        1=FSK    yellow wire
           7=RTS                                        2=Audio 



------------------  end of design notes  -----------------------------