I bought off of eBay back in August my MRC Master Control 20 Walk Around Throttle for analog DC operations. It is the most powerful DC unit on the market to date. After a few months, the handheld is not working properly. It refuses to activiate when power is applied. The base unit is working fine. The phone jacks also work. Anybody else have similar issues and any fixes to this?
Did you try a different connecting cable?
Does the "power monitor" light light up on the main console?
Ed
I have the same set-up, but wasn't overly impressed by the handheld throttle, which doesn't offer much finesse in speed adjustments, so replaced it with this one, from Ken Stapleton Electronics...
It has Pulse Width Modulation, which offers great speed control (there's an adjustable screw on the handheld that can vary the starting voltage), and can handle multiple locomotives if you're running long or heavy trains, or, like me, have a layout with lots of grades. I've had mine for ages. I believe that Ken has created some more powerful ones since I bought mine, but can no longer find his website. If I can find his contact info, I'll post it here.
Below is the description of the throttle:
1MODEL 821A PWM MODEL RAILROAD THROTTLEThe model 821A PWM model railroad throttle has been designed for use with any scale DC model railroad system. Like it’s predecessor the model 820, this throttle has been designed to provide unparalleled performance in both switching and mainline usage. It is easily installed and requires no maintenance. Please follow these instructions for installation and modifications to enhance your operational enjoyment.INSTALLATIONThe model 821A needs a supply voltage source to work. The supply voltage can be 12 to 24 volts AC or DC. The ability to operate from DC power source makes this throttle especially attractive for outdoor operating situations with battery supply (eg. automotive batteries). Applying voltages above therecommended limits can damage the throttle. Voltages below the recommended limits may result in erratic or unreliable operation. The power supply must be able to supply enough current to allow reliable operation to your layout. A supply rated for 3 amps is recommended, however, you can get away with less if you don’t expect to draw the 3 amp maximum. Be warned though, a power supply rated for less than 3 amps can be permanently damaged if the output of the throttle is shorted during operation. Be sure to fuse the power supply’s output terminals to protect the supply. If you are unsure of how to do this consult an electrician or an electronics technician. Connect the supply voltage to terminals 5 and 6.If you have a common rail blocked system and plan to use more than one throttle an individual power supply must be used for each throttle. If you have a fully isolated blocked system (both rails gapped) multiple throttles can be operated from one supply source. Again, be sure the power supply is capable of supplying ample current to operate all of the throttles.The large aluminum heat sink can become very hot during normal operation and will become especially hot in the case of overloads caused by a short applied to the tracks or throttle output terminals. The printed circuit assembly should be mounted so that adequate air flow is available to help cool the heat sink. Do not touch the heat sink unless you are sure it has not become too hot to touch.The printed circuit assembly can be mounted with #6 hardware at each of the four corners of the board. If you plan to mount the PCB on a metal surface spacers should be used in order that the soldered side of the circuit board clears at least ¼” above the mounting surface.ALWAYS DOUBLE CHECK YOUR CONNECTIONS TOENSURE SAFETY !!!TRACK CONNECTIONSThe throttle’s output appears at terminals 7 and 8 connect to the track. Be sure your connections are solid and that wires are not frayed. Use stranded 18AWG minimum insulated wire and make sure the insulation is not cracked or compromised in any way that will cause a short circuit.CONTROL HANDSET CONNECTIONSRefer to figure 1 for handset connections to the printed circuit board. If you are using the optionally available 851HS handset follow the color code beside figure 1. If you plan to construct your own handset follow the connections as per the diagrams included.
2figure 1 –connections to PCB ass’yCONNECTIONS TO TERMINALS1 -speed control voltage input-851HS handset yellow or white2 -direction control voltage input-851HS handset green3 -12VDC handset supply-851HS red4 -handset ground-851HS black5 -AC/DC supply terminal6 -AC/DC supply terminal7 -track voltage8 -track voltageNote -Terminals are numbered on the bottom of the PCB assemblyHANDSET DIAGRAMSThese schematic diagrams outline different handset configurations should you decide to construct your own handset. The standard configuration of the 851HS is shown in figure 2. Variations of this configuration are shown in figure 3. When constructing your own handset be sure to follow standard electronics soldering practices. Always use a clean soldering iron and NEVER use acid core solder or acid flux. Inspect your work to ensure solder joints are clean, smooth and shiny and that connections go to where they are intended.Part values shown are not “carved in stone”. Feel free to experiment with these values. The only caveat is that the “speed” control’s value must not be below 5KOhm or above 50KOhm and it must also be a “linear taper” potentiometer.figure 2-821HS standard handset configuration3figure 3-821HSX fully featured handset configurationThe configuration shown in figure 3encompasses the many differentiations to the handset controls. Feel free to experiment by adding or deleting functions. Experiment with the values of the components and observe their effect on the operation of the throttle. When you have decided on the final configuration, choose a suitable enclosure and plan the control and switch placement for comfortable operation. One-handed control is very desirable and your handset should be maximized with this goal in mind.ADJUSTMENTSThe trimpot labeled “VOLTS” is located within the heat sink area. This should be adjusted to your desired full speed voltage. This can be done by running a locomotive up to the full speed setting of the throttle and adjusting until the optimal full speed is established. The “FREQ” adjustment is factory set at 60Hz and shouldn’t need to beadjusted unless you have a “stubborn” locomotive that may be more responsive at a different setting. Run the locomotive at very low speed and then adjust for maximum controllability in conjunction with the speed control at low speeds. Ken Stapleton
If it's of any help, I do have the MRC handheld throttle, which was working the last time I used it.
Wayne
To the OP: Since you started this thread with the same query as you posted in the 12-year old thread, I deleted those posts and included John's (PRR 8259) response below. That keeps the replies in one thread rather than two...
CRSR2008--
Did you check the plugs and/or your wiring? Sometimes the length of wire run can be enough to make a power supply not work...just saw that with my dcc system when a friend made a new cable for me. It was too long and had too much resistance. As soon as we went back to the regular cord length we were fine.
FYI - for anyone even contemplating a switch to DCC at some point in the future, the various manufacturers have warnings regarding earlier MRC power supplies VOIDING their warranty on electronics. In at least one case, the manufacturer specifically says not to use any MRC power supply at all, and in other cases, companies such as Rapido tell you specifically which power supplies are the ones that you cannot use (typically the older ones as they do not supply "pure" filtered DC current).
One work around is to install a DPDT toggle switch which will allow you to change from DC operation to DCC operation with a throw of the switch. You can only use one mode at a time, but for those in transition between DC and DCC, this method allows you to retain all those old plain DC units for as long as you want to.
The ONLY MRC power supply that I would consider using with current DCC locomotives would be the MRC Tech 7 and possibly the Tech 6 Sound Controller. The older ones are at this point not recommended to use with current generation DCC locomotives as in some cases they can fry decoders. Even some plain DC engines are using decoders now if only just to control lighting features, etc.
After for years being in the "dc only" crowd, I have basically switched to DCC for all the lighting features, etc. and the current diesel sounds which are much improved over earlier efforts.
I have only one plain DC unit remaining, an MTH SD70M-2. All the rest have been replaced.
John
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
It's interesting to me that this MRC product does not run the full output power through the hand-held throttle, which is why you can use phone cable as the connection.
It's a puzzlement as to why they don't convert the hand-held to radio.
Then DC people could have a cordless walk-around throttle.
CRSR2008It refuses to activiate when power is applied. The base unit is working fine. The phone jacks also work. Anybody else have similar issues and any fixes to this?
Hello,
I have actual experience with the MRC CM20, and I have experienced your problem.
When my friend Randy built his N scale layout, beginning back in 1991, at some point he decided to convert it to walk-around control.
Since I did all the wiring on the layout, I did the install. He bought three of the MRC Controlmaster 20s, and the installation was pretty straight-forward.
After less than a year, two of them became problematic. Eventually one failed completely, and the only good one lost low-speed control.
The fix was to throw the MRC controllers into the trash and replace them with Star-Tec Hoggers. Randy bought four of the Hoggers, and the installation was nearly like-for-like. The fourth unit was to convert the yard cab to hand-held.
These have been in service for more than 20 years on the layout, and still are all functioning just fine.
They are not manufactured anymore, but hopefully a good one is not too hard to find.
They do make a terrible noise at power-on, and they hum, But... they work, and keep on working.
-Kevin
Living the dream.
Mrc was once the go to power pack but I have seen so many of them fail. Only have one that still works which supplys the AC to my turntable.
Hi Ed. Yes I tried a different phone cord-nothing. The base unit is getting power as when I engage the handheld, the signal is getting to it. The power light responses to throttle position, the directional works as well as the momentum. I discovered (strangely) that the problem fixed itself after a day or two.
Thanks Wayne for all the great information. I have heard of this type and that it is a kit only project. I suck at electronic building (LOL). As to my problem it seem to have fixed itself. I never discovered why it was giving me problems.
I downloaded the MRC paperwork once I got the unit. Thanks. The problem seem to have fixed itself.
Hi John. Thanks for your help. I do have a heavy duty DPDT toggle that I installed to go from analog DC to DCC. I checked the wiring and connections to see if the wires were touching - nothing there. I use the standard coil plug in that came with the unit and installed three phone jacks. They all work. I thought about the power issues and think that running four locomotives at a time closes to the source might have been the problem. I like to make power moves at my engine facility, which is when the problem started. After a few days, the problem seem to fix itself.
Like DCC, the cable only sends signals for throttle position, direction, and momentum. There is no physical current expect to power the light indicators. That's what I think. I might be wrong, but this makes sense to me. As for radio, I wonder about that too.
I noticed that MRC products are great for the first two or three years, then they seem to start failing at a fast rate. However, there are some that work as expected for 10 plus years. MRC is being compared to Bachmann: hit or miss products. Why would your friend need more than two MRC or Hogger walkaround units for N-scale? His layout must be huge! Did you wire it with multiple dual plug ports or single ports per area? Why are Hoggers no longer being produced?
doctorwayneI believe that Ken has created some more powerful ones since I bought mine, but can no longer find his website. If I can find his contact info, I'll post it here.
I received a reply from Ken this morning. Here's a LINK to his website.
You can run the circuit board for the Stapleton throttle from either the AC or DC terminals of the ControlMaster 20.
doctorwayne I received a reply from Ken this morning. Here's a LINK to his website.
http://www.classixaudio.com/
7j43k It's interesting to me that this MRC product does not run the full output power through the hand-held throttle, which is why you can use phone cable as the connection. It's a puzzlement as to why they don't convert the hand-held to radio. Then DC people could have a cordless walk-around throttle. Ed
MRC seems to have completely ignored that market?
But you can find Aristo Train Engineer throttles used like this:
Or you can buy the newer version here:
https://www.revoelectronics.com/
Sheldon