Second UR91

Over the last 99 sessions from time to time I have had trouble with radio reception dropping out and subsequent loss of control of engines.  Since I could not replicate this issue when I was in the layout room alone and it didn't seem to occur during the Wednesday night sessions I came to the conclusion that the number of people in the layout room during the Saturday sessions was interfering with the radio reception.  So I decided to install a second UR91 at the other end of the layout room and up high out of the way of the various bodies present during a session.

The new UR91 arrived Monday and today I visited Lowe's to get some more Loconet cable.  (Of course the amount of cable I had left over from the initial Loconet installation was just a bit too short!)

This afternoon I installed the UR91.  Now this should be a fairly simple process.  Find a mounting location.  Mount the unit.  Connect the PS-14 power supply.  Connect the Loconet.  Test the installation.  Clean up.  (At least that is the theory.)

I found what I believed to be a suitable location and mounted the UR91.  Next I connected the PS-14 power supply.  (Luckily I had a receptacle in the area for the helix monitor.)  So far so good.

Then it was on to the Loconet.  I tested the new cable (it already had plugs on both ends) with an LT1 just to make sure it was good before I started and it was.  So I passed the cable up to the UR91 and threaded it to the only open Loconet plug which was in Thorny Point.  I cut the cable and installed a new plug.  I used the existing plug on this end of the cable to determine the alignment.  But just for confirmation I check the plug at the UR91 and that is when I found out the plugs had been crossed wired on the original cable and now were also crossed wired on the new cable.  So I cut off the newly installed plug and installed another in the proper orientation.  A test of the new cable with the LT1 indicated it was not getting good contact on all pins.  Since the original cable worked it had to be the new plug.  So off came the second plug and on went a third.  The third was a charm and the LT1 indicated a good cable.  So I plugged the cable into the UR91 and to the Loconet in Thorny Point.

Now it was time to test the new UR91.  To do this I needed to get the existing UR91 disabled.  I had planned to just remove the Loconet cable but it was daisy chained through this UR91 so I unplugged its power supply and with the Loconet cable removed from the new UR91 I tried a radio throttle.  IT WORKED!  Which was NOT good.  Digitrax says the UR91 needs a PS-14 power supply but based on this I don't know why.  It worked just fine with the power from the Loconet.

Next I removed the Loconet from the command station and ran a temporary cable to the next UP panel which removed the original UR91 completely from the Loconet.  I again tried a radio throttle and nothing worked.  At least we now knew the original UR91 was out of the loop.  I then plugged the new UR91 into the Loconet and tried a radio throttle again and NOTHING WORKED!  What was the matter?  A bad UR91?  I tried cycling the command station off and back on and tried the radio throttle again.  This time IT WORKED! Whew.  It seems if the UR91 is not present when the command station comes up it will not recognize it.

I then plugged the original UR91 back into the Loconet and test everything once more and everything seems to be working.  That is until the next Saturday session.

The picture below is the new UR91.

To test out the new configuration of two UR91s I ran the White Hall yard engine to Flat Top to test out the new trackage electrically and mechanically.  All new track work needs adjusting and this was no exception.  But after a few alignment changes everything seems to be working just fine.

The picture below is of the White Hall switcher at BPB Creosote testing the new trackage.