Here's an update on my progress with this.
I did a little investigation into the current detectors that I use on my railway - LDT RS-8 units. Forgetting my possibly underrated cabling these units do create a voltage drop of around 1v, measured at the units installed back in my shed. I did try lowering the output voltage of the Lenz, but there is a consistent voltage drop of about 1v.
I tried bypassing the LDT current detectors completely - they were bypassed in the shed, so the track current was still supplied to all the sections down the same cabling. The loco was then completely happy and travelled around the line without the breaking problem. So I think that there may be some sort of compatibility problem between these and the Massoth decoders.
The Brake on DC function has been suggested earlier in the thread as a possible cause, I understand there are other braking methods in DCC. Lenz has one using Asymetric Brake Modules. I believe Marklin has a different system. As far as I can see Massoth Decoders don't support any of these although according to a note on the Massoth forum all Massoth decoders support Brake on DC since 2007. Clearly I don't have DC on my line, but it would seem to me that something is causing the decoder to issue a brake command. I feel that the current detectors - which certainly are not passive as they do cause a voltage drop - are causing this. It would be interesting to compare the waveforms of the DCC signal straight out of the Lenz and after passing through the current detector. Sadly I don't have one!
So I decided to get an ESU decoder for the 218 instead, so an order was duly made to Wales - and I decided to try a Sound decoder, my first! While that decoder was on order another came up on eBay which I won for a very reasonable price and after having a railcar sound put onto it installed that one in my Railcar. The railcar was running fine on it's Massoth decoder, but only with a Power Buffer installed and this was somewhat unslghtly inside the passenger compartment. The power buffer helped inside the 218, but was not a complete cure for some reason.
So now the Railcar and 218 both have new LokSound XL decoders, and both are running very nicely indeed. The Railcar's Massoth decoder is winging it's way to another forum member and I'm quite sure it will perform perfectly.
The ESU decoder's factory Back EMF settings were not good for either of these locos - both were doing some nasty jerking at starting and stopping, but having altered these (I used the settings recommended earlier in the thread for the 218) they both run very well now.
So that's it - I haven't got to the bottom of the problem. But I have a solution which works for me.
Cheers
I did a little investigation into the current detectors that I use on my railway - LDT RS-8 units. Forgetting my possibly underrated cabling these units do create a voltage drop of around 1v, measured at the units installed back in my shed. I did try lowering the output voltage of the Lenz, but there is a consistent voltage drop of about 1v.
I tried bypassing the LDT current detectors completely - they were bypassed in the shed, so the track current was still supplied to all the sections down the same cabling. The loco was then completely happy and travelled around the line without the breaking problem. So I think that there may be some sort of compatibility problem between these and the Massoth decoders.
The Brake on DC function has been suggested earlier in the thread as a possible cause, I understand there are other braking methods in DCC. Lenz has one using Asymetric Brake Modules. I believe Marklin has a different system. As far as I can see Massoth Decoders don't support any of these although according to a note on the Massoth forum all Massoth decoders support Brake on DC since 2007. Clearly I don't have DC on my line, but it would seem to me that something is causing the decoder to issue a brake command. I feel that the current detectors - which certainly are not passive as they do cause a voltage drop - are causing this. It would be interesting to compare the waveforms of the DCC signal straight out of the Lenz and after passing through the current detector. Sadly I don't have one!
So I decided to get an ESU decoder for the 218 instead, so an order was duly made to Wales - and I decided to try a Sound decoder, my first! While that decoder was on order another came up on eBay which I won for a very reasonable price and after having a railcar sound put onto it installed that one in my Railcar. The railcar was running fine on it's Massoth decoder, but only with a Power Buffer installed and this was somewhat unslghtly inside the passenger compartment. The power buffer helped inside the 218, but was not a complete cure for some reason.
So now the Railcar and 218 both have new LokSound XL decoders, and both are running very nicely indeed. The Railcar's Massoth decoder is winging it's way to another forum member and I'm quite sure it will perform perfectly.
The ESU decoder's factory Back EMF settings were not good for either of these locos - both were doing some nasty jerking at starting and stopping, but having altered these (I used the settings recommended earlier in the thread for the 218) they both run very well now.
So that's it - I haven't got to the bottom of the problem. But I have a solution which works for me.
Cheers