MTH QSI Digital Whistle/DCRU Question

I had several locos with QSI DCRUs, and this wasn't a problem.  All were converted to PS2 10 or so years ago.

In my experience, it is a flaky bug that sometimes occurs with some QSI and Proto-1 sound systems in combination with some transformers. It happened the other day to a Proto-1 unit I was fixing for a friend - and then it was fine. If there is a cure other than a different transformer, I am not aware of it. I haven't seen that happen when using old-style Lionel transformers that used an electromechanical variable transformer rather than a fixed transformer and an electronic control module. 

  Try a lighted car on the track  If it works. a 330 ohm resistor across the hot rollers  and chassis might eliminate the problem.    The resistor might get warm  and hopefully not hot.. I remember doing this when the power- masters first came out..

All - thanks for the info. So this is a somewhat common issue? Huh. I've had lighted caboose/cars on all the tracks. Like I said, there isn't a "regular schedule" this occurs, just occasionally when cycling through the reverse unit. 

I use MTH Z-1000, granted they are about 10 years old and an Z-500 so transformer compatibility shouldn't be an issue. Regardless, interesting this is "common" and I'd appreciate any other comments. Any way to fix this or is it just the way it is?

Clean wheels and pickup rollers especially roller pin.  G

G ,

Been there done that. No change. I've noticed that if I hold the direction button down for closer to 2-3 seconds is when it occurs but again, not always. According to the manual, after 3 seconds of no juice is when the reverse unit "resets" into neutral for start up. Not sure if I'm on to something here but could the delay be just long enough that upon power up the electronics get confused to think reset to start in neutral and a whistle is produced upon power up?

Any way to fix this or is it just the way it is?   Do you have a post war Lionel Transformer? It may fix the problem. QSI stuff was designed to run on pure sine wave transformers.

I only use MTH transformers - 2 Z-1000s and 1 Z-500. Aren't MTH transformers pure sine wave? I would think so considering they used QSI electronics. 

Nope.

Early         Proto-Sound Equipped Engine Compatibility With DCS

Early Proto-Sound         equipped engines (PS1) built in 1995 and 1996 suffered operating anomalies         when used with "shark-fin" or phase control AC Waveforms found in the         AC track voltage of what were then considered modern-type transformers.         Older transformers, like Lionel's ZW model or MTH's then newly released         Z-4000 employed a more "pure" sine wave form of current for which the         PS1 system was specifically designed.

Because these newer         transformers could cause the sound system to act irregularly, MTH chose         to disallow operation with any transformer type affected by the shark         fin wave form rather than suffer complaints that the engine was defective.         The affected transformer types were not listed in the approved transformer         list found inside each engine produced during those years. Because so         few of these "modern" transformers existed in the marketplace few consumers         experienced the automatic transformer rejection.

By 1997, software         designers had pinpointed the shark-fin problem and resolved it through         software and hardware changes in the PS1 circuit board. Consequently 1997         and later PS1 engines do not require the shark-fin transformer rejection         needed in 1995 and 1996.

Users of DCS may have         experienced the shark-fin rejection when attempting to run those engines         on a variable channel. This is because the DCS Track Interface Unit (or         TIU) does not employ the more expensive pure sine wave form of current         found in the MTH Z-4000 and instead relies on the less expensive phase         control AC waveform. While the TIU waveform isn't as pronounced as that         found in those early mid-1990's transformers, the PS1 software will still         reject the current and not allow the locomotive to leave the RESET state.         

DCS users experiencing         this phenomenon should follow either of the following procedures to allow         their PS1 engines to operate with the DCS system.

Z-4000 Remote Receiver         Method

1. With the PS1 engine          on the track, employ the use of the MTH Z-4000 transformer for powering          the variable or fixed channels of the TIU.
2. Configure the TIU          for a Z4K Channel. There are two ways to do this. Either step requires          the use of the Z-4000 remote receiver (MTH part number 40-4002)
3. 1. Configure the          Fixed channel by setting it up through the TIU setup menu as a Z4K          channel.
   2. If using 2.1          software, you can configure a variable channel as a fixed channel          as well. Once configured as a fixed channel via the TIU setup menu,          the channel can be used as a Z4K channel.
4. Give the fixed          (or variable configured as fixed) Z4K channel full power from the Z-4000          transformer.
5. Use the DCS remote          to access the Z4K channels and adjust the track current appropriately          to operate your PS1 locomotive. The shark-fin rejection will be disabled          because the TIU is receiving full power from the Z-4000 transformer.          The combination of full power with the use of the Z4K receiver eliminates          the need for the TIU to regulate the current from the TIU to the track          and thus does not "contaminate" the track current with a shark fin or          phase control wave form. As a result, the track current isn't rejected          by the PS1 hardware and the locomotive should operate normally.
6. The engine will          continue to function and respond to DCS commands as long as it is not          shut down. When shut down, repeat the above procedure to get the engine          to respond again.

Sine-Wave Trick Method

1. With the PS1 engine          on the track, employ the use of an MTH Z-4000 transformer or any older          Lionel ZW or KW type transformer as the power supply for the Variable          Channels.
2. Apply power only          to the TIU via either the Fixed 1 or Auxiliary Power input. Do not apply          power to the variable channel at this time.
3. Scroll the variable          track voltage up to 22 volts using the DCS remote.
4. Now apply 8 - 10          volts of current from the transformer to the Variable Channel you wish          to control. At this point you have tricked the TIU into thinking it          is passing current straight to the track and the PS1 locomotive should          start up.
5. Press the red Direction          button on the remote to allow the PS1 engine to leave Reset. Press DIR          again to park the engine in neutral.
6. Adjust the transformer          throttle up to full voltage. And lower the DCS voltage setting down          to the desired operating voltage the user wishes to apply to the engine.         
7. The engine will          now continue to function and respond to DCS conventional commands as          long as it is not shut down. When shut down, repeat the above procedure          to get the engine to respond again.

Gregg, 

Thanks a lot. I don't own any PS1 engines and again, this is NOT a PS1 engine, just a DCRU and a digital QSI Whistle (all PS2/3 with this DCRC/Whistle and some Lionel Air Whistles)  anymore so this has been a bit of a "re-fresh" experience with the requirements and characteristics of these electronics. I do have a CW80 but it only powers a small trolley line and I can't run an engine on it and we all know how well those work with modern MTH electronics.

I wonder when the Z-1000 came out (same with the Z-500) as I pulled out the operators manual for the engine and looked at the recommended transformer list and I see the Z-4000 and the Z-750. A little research on the forum and the internet showed that MTH transformers are pure sine wave but the Z-controller "chops" it. A few things stuck me:

1) I assume something with the internal, all-in-one construction of the Z-4000 eliminates the "chopping" of the pure sine wave?

2) How is the Z-750 different than the Z-500 or Z-1000? Other than the voltage, I don't see how anything is different. Anyone know when they came out? The MTH website says 2003 for the Z-1000 but somehow I remember them being introduced way before that. 

Every once in a while and possibly with older units the controller could bleed on a DC voltage at times.  That could trigger the whistle.

For the older transformers the controllers where different.  I think now they all use the same higher rated controller.

I understand the DCRU, but have had limited experience with DCRU/Whistle boards.

For PS-1 I only have one board that randomly blows the whistle.  I isolated it to the bottom board.  But have not found the source of the DC leak.  Probably a diode or maybe a capacitor.  G

Thanks G. 

I haven't had any "random" whistle blowing issues before other than with a Lionel air whistle that was resolved after some good wheel/roller scrubbing and "tinkering". Otherwise it isn't an issue. Also, this engine can run until the wheels fall off and not have an issue. It is only on occasion when cycling through the reverse unit. 

My two Z1K bricks are about 10 years old with new controllers and my Z-500 is 100% new so that isn't much of an issue apparently. 

When did the Z-1000 and Z-500 come out? Like I mentioned, the Z-750 is on the recommended transformer list for this loco and the only MTH transformer on the list but I'm not sure if that applies only to the PS1 equipped versions. Strange to think an MTH transformer may/may not be compatible with an MTH train! 

Pull the sound board and plug it back in.

Hi, not sure what the actual difference is in the electronics but it is not the brick where the difference / cause is, rather the controller itself.

That said, using a Z-750 controller in your case you should not experience this issue. 

Now ironically if you were to get one, while it would stop this issue from occurring, sadly you would experience issues using it with some PS 2 units.

I have always only used MTH 75 & 100 watt transformers and controllers and have experienced every issue possible throughout the years. Now I am aware of such and it is less of a hardship. However I have to say that that was not always the case and the stuff that I have experience did very much cause lots of grief Prior to figuring out such. All of which makes me feel bad for the people not so advanced in the hobby.

Needless to say, my solution to the issues was to eliminate the units from my fleet which required the z-750 controller as well as removing the z-750 controller itself from my life. Because with the issues certain Ps2 units had using that controller caused me more grief then being bothered having it or the other units around in the mix since they were the minority and my PS2 stuff is definitely the majority.

Marty,

Thanks I opened the tender but don't see any obvious plugs, etc. Not feeling very comfortable messing around in there I buttoned it back up. 

Subway - thanks. I tried my Z-500 and it still reproduced the issue. Replacing the Formers is not an option. Since it runs fine as-is, I'll just keep running it. I think it would be a good candidate for an air whistle one day...