After following this topic for some time, I feel I must join the debate, and state from the outset that I agree completely with John.
I have been using the catenary to power my electric locos for over 40 years. When digital came on the scene, I initially followed the advice of Lenz (I chose DCC because I had fitted all my Marklin locos with Hamo magnets back in the 1980's and operated them with DC using an old Hammant & Morgan Duette) and did not attempt to power the locos through the catenary. The locos worked (I was using only 2 rail at the time ( a long story) but they did not run as smoothly or as reliably as they had previously done with the catenary and I was considering giving up DCC.
After some discussions with a retailer at an exhibition in Canberra in 2004, I decided to tr(y powering the locos through the catenary. At the time, I was using the old pressed metal Marklin system which was soldered at the joints due to age and tarnishing/rust. The system worked immediately; the locos ran smoothly and reliably as they had before, with the added advantage of the fine control that is possible with digital/DCC. I was also able to return all my Marklin locos to service.
I have since constructed a new layout which is fitted with Sommerfeldt catenary using Peco track and points. It is a simple layout built for exhibiting and was at the exhibition held by the Marklin Modelers of Sydney at Beecroft in 2012. I decided to use the 0.7mm wire sections for strength as exhibition layouts take quite a pounding when being moved to and from exhibitions. The layout has worked reliably since built. I have experienced none of the problems outlined by Chris, and have not lost any decoders (I use decoders from TCS, Lenz and Trix, but mostly ESU LokPilot III's and IV's) powering locos through the catenary. I can't say the same for 2 rail. I have one HAG Re6/6 that has destroyed 3 decoders while operating in 2 rail format, but I have experienced no problems since I converted it to 3 rail using the catenary 1n 2004.
I recall that Lenz stated in their instructions (I am relying on my memory here) that in some cases, decoders had been destroyed when powered through the catenary because they had received up to double the voltage that they were designed to handle. AS stated above, I have never experienced this or any other problem, and I have often wondered why manufacturers would advise against using the catenary to power trains digitally. I may have an explanation for this,and a way of avoiding it
In the first half of the 1990's, Marklin introduced a new model of the SBB Ae6/6. As the prototype Ae6/6 is a particular favourite of mine, I acquired both the green version locn No 11414 and the red version Loco No 11425. Both locos were fitted with Hamo magnets and operate on DC through the catenary as with all my electric locos. Their performance was terrible, and they would not run smoothly at all. I was unable to improve their running qualities, and they sent most of the next 10 years in their boxes. I did notice one day while operating them in dull light that there was a blue arcing of electricity at the elbow joint on the pantographs of both locos, and I seem to recall that the pantographs were hot to touch.
After I had converted most of my electric locos to operate on DCC through the catenary in 2004, I decided to have another attempt with these two Ae6/6's. At about this time, I had become aware of the benefits of using graphite to improve electrical conductivity, particularly when used for 2 rail DCC. Conscious of the warning given by Lenz, and the arcing I had observed in the pantographs of these two locos some years previously, I wondered of the problems being experienced in using digital/DCC through the catenary could be caused by electrical resistance in some pantographs. After I had installed a decoder in the green loco, a placed a small drop of oil mixed with graphite of every joint of both pantographs. I then placed it on the track and it ran perfectly for the first time since I had acquired it 10-12 years previuously. The red loco was then converted and it also ran perfectly. I have had no problems with these locos since.
Why I had this problem with these 2 locos, but none of the other 30 or so other electric locos I own, I do not know. I believe that it would only be an occasional problem with some pantograhs. Others, like John, may never experience this problem ever. As a precaution, I have given all the pantographs of my electric locos the graphite treatment, and I have had no further problems.
I would never consider powering any of my electric locos other than using digital/DCC through the catenary.
Geoff
Edited by user 30 March 2013 11:11:05(UTC)
| Reason: Not specified