Using the HAL ST-8000 HF Modem With the Yaesu FT-1000MP Transceiver and RTTY by WF1B

The HAL ST-8000 is a high-end RTTY unit. It contains no DSP, but the quality of its filters is well known. These units are showing up at flea markets, and sometimes those selling them have no idea what they're worth. If you see one in good shape at a flea, think about picking it up!

With lots of internal DIP switches, the ST-8000 is able to accommodate many types of transceivers. Getting these settings just right is a bit of work. This document explains the settings I used in the ST-8000, related FT-1000MP settings and the configuration of the RTTY software by WF1B to talk with the modem.

It is my hope that this information is useful to someone else who needs to set up the same combination. Perhaps they'll have an easier time than I did!

Interconnection Assumptions
My interconnects make the following assumptions:
FSK signaling operation
Connections made to RTTY jack on FT-1000MP only
ST-8000 Switch Settings
Receiver Related Switch Settings
Since I pull audio from the fixed-level output on the RTTY jack of the FT-1000MP, I set the switches in bank S1 as follows:
S1-5 ON
S1-4 OFF
S1-3 ON
S1-2 ON
S1-1 OFF
These settings are for 600 ohm impedance, unbalanced. Note: the audio is fed into a 1/4" headphone jack. Connect the tip of the plug to the RX Audio from the FT-1000MP, and the other two connections to ground. Failing to ground the middle ring will result in no RX decode.

 
FSK Transmit Settings
S2-5 ON
S2-4 ON
S2-3 OFF
S2-2 ON
S2-1 OFF
Having S2-1 in the ON position resulted in a lack of shift signal.
S3-5 ON
S3-4 OFF
S3-3 OFF
S3-2 OFF
S3-1 ON
S4-5 ON
S4-4 ON
S4-3 OFF
S4-2 ON
S4-1 OFF

 
Front Panel Settings
The Front panel of the ST-8000 provides lots of things that can be twiddled. Here are the settings I use, at least as a starting point:

Regen OFF
Normal/Reverse: Normal
KOS OFF (center position)
Anti-space: OFF
Print Squelch: Full counterclockwise
Detector: FM M/S
Mark Frequency: 2125
Space Frequency: 2295
Shift: 170
Input Baud: 45
Output Baud: 45 (not used)
Diversity: full counterclockwise
FT-1000MP Settings
The only setting affected on the FT-1000MP, is the FSK Keying. The ST-8000 switch settings above require the FSK Keying on the FT-1000MP be set to Normal.
RTTY by WF1B Configuration
Below are the relevant portions of the RTTY.INI file. Some of the lines here probably are not needed and may be left from running with a P-38. I'll try to whittle the list down to the bare essentials.

[TNC1]
ComPort=3
Usos=Yes
Diddles=No
Type=BAUDOT-DRV
CharDelay=3
Normal=Yes
Mode=RTTY

[COM3]
BaseAddr=$3E8
IrqNumber=9
HandShake=none
BaudRate=45
Parity=None
DataBits=5
StopBits=2

Obviously you'd replace the com port settings with whatever com port you wanted to use. The BAUDOT-DRV setting will result in 5 bit baudot passing over the COM port between the ST-8000 and the computer.