JeffreyJ posted:Hello Everybody:
It is the LCRU that is bad. Connected the sound card directly to track power and it works great with both the Commodore and Hudson sound chips. When the sound card is plugged into the tether it does not work in either conventional or command. Placed a VOM on pins 1 and 2 (they supply the sound card power) from the engine and received a reading of about 12v in conventional. I suspect that the current output is the issue most likely caused by a failed card or an aged solder joint. I plan on re-soldering the wires to see if that fixes the issue.
Hold-up for a minute... unless I'm reading something wrong, what you've said doesn't make sense.
1) You've proven that the sound system works when connected to track power. That's good, as it eliminates things like the speaker and volume pot.
2) It doesn't work in conventional or command when connected to the tether, but you're getting a reading of 12v in conventional on pins 1 and 2. If your track power is also 12 volts, then that's good. Track power and the voltage on pins 1 and 2 should be exactly the same.
3) If you're in conventional mode, and you're getting the correct track voltage at pins 1 and 2 across the tether, and you know the sound system works, then there is no reason why it wouldn't work. If you trace pins 1 and 2 (black and black with the red stripe) back through the locomotive, you'll see that they're wired DIRECT to track power. There is no LCRU or any other electronics involved.
We still don't know if your LCRU is good or bad, but the above scenario should work in conventional. I suspect that the tether is not delivering track power to the tender.
TRW
