I would like to hear from anyone who is successfully keying the FSK and
PTT lines via the ACC2 connector on the rear panel of the TS-590SG. What
serial adapter and what hardware interface are you using to do so?
I have tried two different interfaces using optoisolators to attempt FSK
and PTT keying from a serial card to the rear panel ACC2 connector. Both
attempts have failed. I am using MMTTY software for keying and I do get
the requisite signal change on TXD pin 3 (FSK) and RTS pin 7 (PTT)
lines. I have also verified proper setup of the '590 by manually
grounding the inputs PKS pin 9 (PTT) and RTTY pin 2 (FSK) on the ACC2
connector.
However, I *think* the problem lies with the serial card not providing
enough voltage/current for the optoisolators to completely turn on and
provide a hard ground to the ACC2 inputs. I have tried two different
serial cards and one swings from -4.9 to +5.0 VDC on the data lines and
the other card swings from -3.8 to +3.9 VDC. The cards I am using are a
two port generic PCI Express SI-PEX15037 and a four port Perle Fast 4
PCI card. Does anyone know of a serial card that has a full -12 to +12
VDC swing?
One of the hardware interfaces has 4N25 optoisolators and the other uses
Fairchild FOD852 optoisolators. There are 1K series resistors in the
input line to the optoisolators and I have tried various values (100,
220 & 470Ω) with limited success but nothing consistent.
While my objective was to keep the rig isolated from the computer, I am
thinking about building an interface that uses NPN transistors for
keying. Is anyone using NPN transistors to key their '590? Are you tying
the ground from pin 5 of the RS-232 port to the pin 4, 8 or 12 ground of
the ACC2?
Any input is appreciated...I have been off RTTY since purchasing this
rig in November and I want to get back on the bands.
Thanks,
Tim WS4V
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