I also tried Steward Cobbs RS422 - Rs232 hack but with no joy in the
beginning. First I had used the standard RS232 com1 port of my computer
with no success. Later I tried my Prolific USB-to Serial adapter and
things got better. After some measurments and looking at the pinout of
the RS422/1PPS connector I've found somewhere on the Net, I made some
additions to Stewards hack at the RS422 male plug:
connect pin3 (Ground) to pin4 (Rx+) and add an 150 resistor from pin 3
to pin 5 (Tx+). This works reliable to the the Prolific but not reliable
with the standard com1 port. The reason seems to be that the Tx- (pin 9)
voltage swing re Ground is only abt. 3.5 V. This could explain the mixed
success of other members.
hope this helps Götz
btw: will the RFTG-REF1 unit I have work standalone? I still have the
STBY-led blinking after more than 24 hours and 3 to 8 satellites in
view, all other leds off.
Am 30.10.2014 01:11, :
HI
There are a few possible variations:
1) Different power supply voltages
2) Cheating RS-232 versus a proper RS-422 converter
3) The “right” interface cable (what ever it’s pinout is) versus a VGA cable (
or no cable at all…)
4) The HP interface versus the Lucent one
5) Windows 3.11 versus Windows 10 beta (or maybe something in-between).
I’m only observing that some have had more luck with these than others. Since
they are all NOS, they should all work. That suggests one or another hookup
issue. I don’t think there is any need for ultra long detail lists. Stu took
care a lot of that. I don’t have one, so at this point I’m just an observer on
the sidelines.
Bob
Most time-nuts want to see more than a pretty green light. The old
RFTG series allowed you to hook up a PC to the "RS422/PPS" port and
peek under the hood with a diagnostic program. The program is
available on the KO4BB website. It is written for an old version of
Windows, and I had no luck getting it to run under Windows 7. It does
run under WINE (the Windows emulator for Linux) on Ubuntu 12.04 LTS.
To use it, you need to make an adapter cable to connect the oddball
RS-422 pinout to a conventional PC RS-232 pinout. The adapter cable
looks like this:
RFTG PC
DE-9P DE-9S
7 <----------> 5
8 <----------> 3
9 <----------> 2
(According to the official specs, this is cheating, because you're
connecting the negative side of the differential RS-422 signals to the
RS-232, and ignoring the positive side of the differential signals.
However, it's a standard hack, and it's worked every time I've tried
it.)
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