UR91 Simplex Radio Receiver

Q: Where do I locate UR91 for best performance? A:  The UR91 works best in simplex radio mode if it is mounted in a central location on or near the ceiling. A few layout configurations may require a second UR91 for best performance.If the UR91 is also to be used in IR mode, then the recommendations for the UR90 should be followed.

Q:  I noticed a little black button on the circuit board of the UR91. What is it for? A:  The push button is a diagnostic tool for Digitrax technicians and it cannot be used by the user for anything.

The jacks on the front and sides of the UP5, UR92, UR91, UR90, and LNRP front panels are Throttle Jacks and should only be used for connecting throttles to LocoNet.  They should not be used to connect to other LocoNet devices.  The jacks on the back of these units are LocoNet Jacks that are used for connecting LocoNet devices to the network.  Technically speaking! These units were designed to have the FRONT jack's second Railsync differential signal run as a diode-or'ed power source (for throttles).  This means that some cable orientations and power loads could cause unexpected operations in downstream LocoNet devices ...

  Q:  Can I mix UP-5s with Radio and IR panels? I want to upgrade slowly and still use the 400 throttles and the UT throttles while I mail them in to you one at a time for conversion to radio. A:  Yes, and you can continue to use the UP5's after conversion to radio; for instance, if you have visitors who bring their own Digitrax non-radio throttles. That's the real genius of LocoNet, since you can add to your railroad in any way. Note that you will need to plug in your throttle to LocoNet initially to select the locomotive before you ...

Follow these simple instructions to determine the best location/s on your layout for installing your UR panels for the best possible infrared or radio reception. With LocoNet, you can use Infrared, Duplex Radio and Simplex radio individually or in any combination on your layout.You'll need to be able to observe whether your command station is receiving commands from the UR panels when you are installing infrared or radio receivers and transceivers.  Your Digitrax command station makes it easy to determine when the system is receiving a signal and when it is not.  You can observe the NET LED and the Track Status Indicator or your ...

Simplex Radio Coverage One UR91 should provide full coverage for a typical model railroad under most circumstances. Simplex Radio reception is affected by metal objects between the throttle and UR91 simplex receiver, or large metal objects adjacent to the receiver; a furnace is one example of such an object. Such objects cause a second reflected signal, impairing the radio throttle signal's ability to reach the UR91. In this case, the receiver gets the signal directly from the throttle, then another signal right on top of it from the reflection. Moving the UR91 to another location may solve this problem, or you ...

Here at the Tech Support Depot, it has been our goal to improve operators' understanding of the Digitrax system of model railroad command control. We often see thoughtful words from others who are not employed by Digitrax that still have an in-depth understanding of the product line. Here, Doug Stuard talks about the UR91; these words originally appeared on the Yahoo Groups Digitrax discussion list, and are used here with his kind permission. UR91 and Throttle Antenna The UR91 antenna is the pair of 3" wires that sprout from the PC board that are arranged in a "V" similar to ...