brammie

Just had notification from Amazon that delivery forecast as 22 Sep! The items were listed as "In Stock", but I now see that the small print identifies source a HK!

Other than for trade, the UK supply of small value resistors is quite limited - but I have ordered a number of 4 ohm and 5 ohm, both 5 watt. Once to hand, I can try various combinations in parallel and in series in the hope of getting that Lima speed fixation under some sort of control!

Thank you for your interest Izzy. Firstly, to answer your questions, (1) Yes, the same address loaded in each decoder. (2) The LIma Class 20, when previously fitted with a Hornby TTS only, ran happily with the nose pointing in either direction. I spent the afternoon removing the Lenz decoder from the Lima Class 20 and reconnecting the Hornby TTS wires left unconnected. It runs perfectly again, with all sound functions also working perfectly. As a matter of interest, I fitted the Lenz decoder to a second Lima Class 20 chassis that I own, and it runs pretty well in that. Testing the Hornby Class 20 together with the Lima Class 20, both with TTS decoders (but not in consist) shows the Lima to run some 20% faster than the Hornby for the same throttle setting. The next initiative is to install a small resistor in line with the Lima motor connections to reduce the voltage, and so the speed. I will start with a 4ohm 4 watt and take it from there. One good thing came out of the exercise; what a belter to hear two Class 20 locos giving it out from their speakers!

Do they both have traction tyres? If one is with and one without, that could make a real big difference in how the locos perform. JSpencer: The Hornby driving wheel bogy has traction tyres on a single (opposing) wheel of each axle only .The Lima Class 20, as is generally well known, has traction tyres on all four driving wheels. Thank you for your interest. I am currently banking on the in-line resistor plan to reduce motor voltage output from the decoder.

Following advice from a member on another site, I attempted to speed match my Lima Class 20 loco fitted with a Lenz decoder to the Hornby Class 20 with TTS sound. I spent a day trying to rig the CVs, and finally settled for something workable but not ideal. I then added a Hornby TTS decoder in the Lima, wired up only to the wheel pickups (black and red) for supply and only speaker outputs connected. Whilst the loco was happy to run well under the control of the Lenz decoder, it was clear from my ECoS dispay that all was not well. Ordinarilly, each of the (20 plus)TTS sound functions is represented by a symbol on the ECoS controller, but in this case - nothing. I checked out wiring, again, and was left scratching my head, but was left wondering whether red and black only to the Hornby TTS decoder are sufficient. Whilst walking my dog this morning, the thought occured to me that I might rig the Lima Class 20 with a Hornby Class 20 TTS decoder again, but this time insert a dropper resistance in series with the motor connections to reduce the motor speed to that of the Hornby Class 20 for the same throttle setting. At a guess, I could start with 4ohm, 4watt (max motor current 1 amp) and then replace with higher/lower R value to achieve speed matching of the two locos at cruising speed. If that idea worked, I could then set the two locos up to run in consist, as per the ECoS manual. Anyone see any obvious problems with the idea?

Thank you for that SRman. I wish it were that simple; neither CV5 nor CV6 are listed in the Hornby Class 20 Sound Decoder Manual, and reading them on the ECoS Controller shows "Error" for both CVs. There is however reference to "CV150-154: Motor Control Method", the lengthy explanation of which seems to imply that motor speed control is achieved through compensation under load - as opposed to setting loco speed for a specifc throttle setting (which is a must for two locos in consist).

Here's hoping: I have two Class 20 diesel locos which I intend to run in consist. One is an out-of-the-box Hornby with TTS fitted, the other is a Lima which previously ran extremely well on a Lenz chip and which continues to run extremely well with a Hornby TTS chip fitted. Both work fine individually on my ECoS controller. My problem is the difference in their speed for specific throttle settings. On test track with both locos selected on the ECoS screen the Hornby runs approx 25% faster (in either direction) than the Lima for the same throttle setting. I have been assuming that this can be dressed out by speed matching through CV settings, but I can't find any simple process by which to achieve this. I am sure that this problem is not unique to my locos, so would greatly appreciate any advice from others who may have encountered a similar problem. Brammie