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First Looks

Digitrax Products with Features that Caught My Attention


Advanced Duplex (Radio) Super Throttle

Brief Description

This is Digitrax's new generation of throttle. It can control two active trains and has a large, back-lit color LCD display.

Compared to the DT402/DT502 throttles, it has fewer buttons (23 vs. 32). Functionality of the additional buttons were moved to menus. If anything, this is an improvement as you are not looking over a sea of buttons to find the one you want as well as the menus help focus you on the things appropriate for what you are doing.

It is about a quarter inch wider and about a half inch thicker than its predecessors.

It took me about three months to get my throttle. The chatter on the Digitrax chat group seemed to indicate that Digitrax had some initial problems. The throttle I received a few days ago worked fine.

I have the duplex radio model. It worked fine with my existing UR92 duplex radio transceiver Loconet interface.

My Experience

This throttle is very different looking than the DT402 throttle I had used for so many years. With fewer buttons and menus, I wisely decided to read the manual before hacking away at keys. The manual is only 24 pages long and well worth the read. At a minimum, watch a YouTube video on your new toy. After reading the manual, I was off and running. Everything was easy to find. Setting options, setting up routes, programming and all the functionality of the older throttles is there.

While the new throttle has menus, the functionality that you are accustomed to with their previous throttles remains unchanged. For example, to acquare a locomotive you press the loco key, enter the address, and then press the loco key again. To dispatch, you will see a menu item for this as well.

The display has more information and is less cryptic than its predecessors. You will find on-screen menus related to what you are doing and a scrolling help message.

As a nice touch, I found their new implementation of all 28 functions to be easier to know which functions you are accessing as well as the displaying which of those 28 are active.

If you have found their older throttles a challenge, I encourage you to check out this new throttle. I found this throttle very easy to use.

To minimize power drain, the throttle uses an LCD display. As the manual warns (You read it, right?), be sure to be looking at the display straight on. As with any LCD display, it looks different at an angle. This happened to me. A loco I did not have selected and was displayed in gray, looked black - meaning selected - at a angle.

I like that the throttle uses AA batteries rather than a 9V battery, goes into a power saving mode, can be turned off so you don't need to remove the batteries, and has an optional rechargeable battery pack. If you have a Digitrax PS12 wall transformer, it meets Digitrax's specifications for a charger for your DT602(D) when using the optional Ni-MH battery pack. Use a Digitrax PS-14 wall transformer to charge the battery pack. The older PS-12 should work as well. DO NOT try to recharge regular AA batteries!

The throttle can be gripped in it's curved, upper section and you can operate the speed and direction keys with your thumb. That's my experience, but I have large hands. I tend to operate my throttles and my cell phone with two hands anyway. If one hand operation is important to you, be sure to try one of these throttles before buying it.

Like some of the other larger throttles on the market, this throttle doesn't fit the popular plastic throttle holder. Making your own, larger throttle pocket is not a big deal.

On the video I watched, it mentioned the loss of function keys 10 through 12 that are available on the older throttles. This must be something that Digitrax addressed as my DT602D had F10 - F12 on the softkeys D, E, and F. If ready-access to functions F10-F12 is important to you, have no fear, they are there.

Power Off and Track Power

The only problem I had was when I tried powering down by pressing the power button. The menu would appear for an instant and then go away. I couldn't power down. Occasionaly it would work. So I wrote Digitrax's tech support. In a matter of minutes, they got back with me.

They informed me that the power key actually has two buttons under it. All I needed to do was press the left side of the key. Works great now!


HO Scale Turnout Signaling Kit


Digitrax offers signal masts in both HO and N scale that are intended to be used with their SE8C Signal Decoder. Kits are available for signaling turnouts or your mainline. They also offer a Terminal Strip Mounting Kit for use with realistic, third-party signals. This first look is at the HO turnout signaling kit. For more on these other kits, visit the Digitrax website at:

As you can see from the above picture, the SHABC kit contains everything you need to signal a turnout. While the signals lack realistic details, this kit is very appealing due to it's low cost, easy installation, and removable masts.

Pathway to Realistic Signals

The three-signal SHABC kit is about the cost of a single third-party signal. What isn't there to like about that? Signals can definitely dent your bank account. When you can afford more realistic signals, this kit can be easily modified to work with your new signals by cutting of the Digitrax signal mast and soldering on the wires to your new signals. You can also solder a after-market mast to a pad on the base of the Digitrax mast circuit board. In the meantime, you have something that works well. If you think you are wasting the signals, you are, but in the grand scheme of things, the parts that you cut off in the future and discard are only worth a few cents.

Removable Signal Masts

This is another feature that gets your attention. Being trackside, signals are right in harm's way; particularly when track is being cleaned. Digitrax signals are plugged into their SMP1 connector (in lower right of the picture above) mounted under the layout. Just pull up on the signal mast from above the layout and get it out of the way while cleaning track. If you clean your track without removing your signal first and damage it, you can just install a new signal mast.

Pretty it Up

The mast is a circuit board; so it isn't round. This can solved with some plastic puddy and shaped with your fingers. You can then paint the mast to be a more appropriate color.

Some sort of a hood over the lights is desirable. This can probably be done using 3-D printing. If you have done this and don't mind sharing, I'll post the 3-D files here on my website. Some public and university libraries have printers for use by the public. They charge about ten to twenty cents per gram of plastic - a real deal! I can't see buying a printer for myself.

As a finishing touch, you can add a ladder up the back.



Occupancy Detector, Transponding, and Power Management for 8 Zones


Occupany Detector, Transpond, Auto Reverser and Power Management for 1 Zone


BXPA1 with connectors removed


These products share a lot in common, so I will cover them both here. I will be sure to clearly point out when I am only writing about one or the other.

The BXP88 is an eight-zone (section) transponding receiver and block detector. It also has an electronic circuit breaker for each detection section. As with any block detector, you can't put an automatic reversing unit after any block detector. (Usually you can put them before a block detector.)

The BXPA1 is a single-zone (section) transponding receiver, a block detector, an electronic circuit breaker, and a automatic reverser. So between the BXPA1 and the BXP88, you should have everything you need.

Putting all these capabilities in one unit reduces the number of things you have to buy as well as less work to install. All depending on where the units are located, this can be a great help.

Both devices use a proprietary means for detecting occupancy and is very sensitive. It can detect rolling stock with detection resistors on them as high as 22,000 ohms (22k-ohms).

Both units report occupancy and transponder ID over Loconet. Your DCC system does not need to be a Digitrax system to use these products. You will need to be using software like JMRI driving Loconet to receive the occupancy and transponder information from these products.


The documentation that comes with the BXPA1 is shorter than what comes with the BXP88. Go to the Digitrax Tech Support Depot and download the KB1058 document, "BXPA1 Advanced Setup" or just follow my link to it. This tells you how to adjust the "pots." (That's slang for potentiometers. That's a mouthful! Now you know why those in the know simply call them pots.) It also includes info for hooking external devices and output display as well as a few other things you may find yourself wondering about. By-the-way, don't turn the pots until you have read the instructions for doing so. With too much force, you could damage them.

Removing the Terminal Blocks

The terminal blocks on both devices can be removed and the orientation changed so that your wires can leave the device either horizontally or vertically. You can see an example of the removed terminal blocks in the above photo of the BXPA1.

The terminal blocks fit on the pins very snuggly; as they should. Since they fit so tightly, I was a little nervouse getting the first one off. I didn't know exactly where to pry and didn't want to damage anything.

I then figured out way to get the terminal blocks off safely. Take a ball-point pen and stick into one of the terminal holes on one end of the terminal block and lift a little. It's firm, but it will budge. Don't move it a lot or you may risk bending the pins. Then move the pen to the opposite end of the terminal strip and lift there. Keep working it back and forth until the connector comes off.

You can use the terminal blocks in either orientation; your choice and whatever works best for your situation. I only caution you that if you wired the block and then decided to change the way the terminal block mounts, note the left most screw when horizontal, will become the right most screw when vertical. So if you wired the block, you will have to move all the wires.

While the terminals of the BXP88 are covered up by the terminal block when horizontal, don't panic. Just look at the documentation. There is a clear diagram there.

The BXPA1 doesn't have a diagram in the instructions. So that you don't have to remove the terminal blocks to see the labels, Here they are:


Left OUTB OUTA INA INB        


Set Points

The maximum current setpoint for the BXP88 is 3 amps. If you are using it with entry level DCC systems that have a maximum output of less than 3 amps, it probably won't trip. The BXP88 does not have adjustable thresholds for its electronic circuit breakers.

The BXPA1 trip point can be adjusted with the pots. Just read your KB1058 document.

Analog Locomotives

These transponding devices don't work with analog locomotives; which don't support transponding anyway. The BXP88 will disable zerro stretching in your command station. Zero stretching is the DCC technique for running analog locomotives. If you had a analog locomotive you were running that doesn't work after you hook up a BXP88, now you know why. Time to put a decoder in that locomotive!

Local and Remote Indicators

Both devices provide for local and remote status indicators. The local indicators are intended for troubleshooting and the remote ones are for you control panels.

Note that the BXPA1 output requires a resistor in series with the LED where as the BXP88 does not. Let this be a lesson to you. WHENEVER hooking up an LED, make sure you read the documentation carefully and KNOW whether you need a resistor or not. Falure to do so may let the magic smoke out of your device and then you will have to send it in for repair.

- test individual zomes for tripping. test twisted buses., test detector sensitivity.


First Looks in the works: SDXH186MT, Zephyr Express


Duplex Super Throttle

Turnout Signaling Kit
Occupancy Detector, Transponder, Auto Reverse, Power Management

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