Dramatic reduction in speed after fitting a 121 sound chip

[Michael Nolan]

I have just fitted MM0567 Sound Chip to my 121 and the speed is non existent I am running in DC have I missed something, any help please.

 

[Joe Keegan]

Yes , you have limited functions/speed on DC .

You need to operate on DCC to achieve the correct functions/speed.

Have you read up in general on using DCC/DCC decoders , using DCC decoders on DC ?

Check out this DCC site “ wiringfordcc.com “ and the section “ DCC for beginners “

Do not use DCC decoders on DC feedback controllers as this will destroy the decoder and you no redress on a damaged decoder used on a DC feedback Controller.

 

[Michael Nolan]

3 hours ago, Joe Keegan said:

Yes , you have limited functions/speed on DC .

You need to operate on DCC to achieve the correct functions/speed.

Have you read up in general on using DCC/DCC decoders , using DCC decoders on DC ?

Check out this DCC site “ wiringfordcc.com “ and the section “ DCC for beginners “

Do not use DCC decoders on DC feedback controllers as this will destroy the decoder and you no redress on a damaged decoder used on a DC feedback Controller.

 

Thanks Joe but the IRM site sold them to me as 'The LokSound 5 decoder works for analogue DC and AC (!) layouts.'  so why am I having this problem. 

Sorry for my ignorance but what is a DC feedback controller, I am using a basic Gaugemaster 4 Model Q to supply power to the track. To get very slow craw speed I have use full power speed on the controller.

[murrayec]

@Michael Nolan The DCC chip is pre-set for prototype running so slow startup speed and stopping. Have you left the loco run for a while to see if it speeds up?

Gaugemaster DC controllers have a low setting on full throttle, so the top speed is slower than other DC controllers! You may need to program the speed settings on the DCC chip if you still experience the problem.....

Eoin

[Noel]

13 hours ago, Michael Nolan said:

I have just fitted MM0567 Sound Chip to my 121 and the speed is non existent I am running in DC have I missed something, any help please.

A DCC decoder has very limited and basic functionality on a DC layout. Our layout was DC converted to DCC but I can switch it back to DC mode by swapping two cables. I usually do this to test run new locos and run them in. The decoder you have obviously has been DC enabled as factory default setting (ie bit 2 of CV29 is on). You won’t have any control over CVs 3 & 4 ( acceleration and deceleration), nor CV5 (max voltage=max speed). If you had access to a DCC controller or somebody else’s DCC system these could be programmed.

Questions for you:

1. if you turn on your DC controller and turn it to max, leave it at max for 60seconds, does the loco accelerate extremely slowly but eventually attain a higher track speed?
    
2. How does the loco respond on DC with the decoder removed and the original decoder blanking board is plugged back in? Worth checking that a stiff chassis is not the problem (Ie in need of lube)?
    
3. is it the same in forward and reverse?

I’ll test run my sole MM supplied ESU LokSound 5 decoder tomorrow on DC to see how it behaves on DC at max voltage (using a gaugemaster DC controller) and report back.

basically you have no control over CVs 3,4,5, and 6 (mid voltage) without access to a DCC controller, nor access to light functions or driving functions, horns, flange squeal, etc, just default engine noise and default running lights once the loco is moving (ie getting at least 4-12volts).

PS as Eoin has already advised ensure you don’t have a DC track cleaner (Eg Relco O’R gaugemaster wired in orbit will destroy a DCC decoder).

Good luck. Will let you know tomorrow how I get on with the DC test.

[Noel]

Apologies @Michael Nolan I didn't get a chance to try the loco on DC today, preoccupied with snow up here in the mountains. Will try during the week.

[Old Blarney]

Slow Running

I wonder if the cause may be this?  The Murphy Models Decoder has a Slow Speed Function setting. When selected this function (F6)  significantly slows the speed of a locomotive.  The Slow Speed Function (F6) is used  to reduce locomotive speeds, and thus, allow shunting movements to appear realistic , as well as  allow excellent slow speed running, especially within restricted track areas. 

If selected, the F6 button, will reduce the fastest speed of a locomotive to something  just faster than  a slow crawl.

I hope this may assist you.

White..

[WRENNEIRE]

He is using DC David, he cannot use Function 6 without a DCC Controller

[Noel]

8 hours ago, WRENNEIRE said:

He is using DC David, he cannot use Function 6 without a DCC Controller

Indeed this is going to make it difficult to solve.

I spoke with ‘a man in the know’, who understands a lot more about these matters than I do. First off he tells me the Murphy Model supplied decoder is an ESU LokSound V5 DCC which means its not AC analogue not that many use that now a days.

So its not AC and DC ready as previously stated, DC only. The DC settings are set at 9v so its not going to move until it gets 9v and the motor settings are set at 8v so that all may be having an impact in this slow running.

My advice would be to try and find a way to use a DCC controller, or run the loco on somebodies DCC layout or a club DCC layout so that you can examine and possibly change CV settings that could effect DC running (ie limiting max voltage to the motor from the decoder when the track is providing 12v).

But my final thought is one of the main advantages for me personally of DCC over DC is aside from better motor control, and simpler wiring is the ability to run and control locos equipped with DCC sound. Running a sound loco on DC greatly diminishes the functionality available.

Will let you know later in the week how one of my 121s runs on DC with that MM supplied decoder. Last thought, consider in the future the possibility of getting one of the entry level DCC controller systems like a Z21 or an NCE PowerCab (assuming this loco and decoder are without fault).

 

[Old Blarney]

Wrenneire and Noel,

Thank you for your replies. I assumed the situation was, that which you describe in your reply to my post. I made my suggestion on this basis  The decoder could have been reprogrammed prior to its installation in the offending locomotive.  If so, then perhaps F6 may have been selected in error.  Were the locomotive with its decoder to be placed on a DCC Layout the setting could be accesses and appropriate changes made. 

My very best wished to everyone.  I do hope a solution is reached for Michael's sake. I certainly know how disappointing it is when your expectations are dashed.

White.

Edited January 25, 2021 by Old Blarney

[irishthump]

Had a good look through the Loksound V5 manual last night and both the starting and top speeds of the loco while on DC control can be independently set. There is also a setting for allowing the lights and sound to activate before the loco moves off.

Unfortunately though Michael will need acess to a DCC controller to check and adjust these settings.