If you want to maintain DC for some time while still having DCC operational, it would be best to arrange things so that it is impossible to have both running simultaneously. You want to disconnect one source from the layout and power it down before you bring the other one up. Having a layout which is part DC and part DCC is a disaster waiting to happen.
A lot of today's decoders are "dual mode." They will operate on either DCC or DC. So, you might start the conversion by replacing a few decoders, but continuing to run your layout mostly on DC. Set up a small track for your DCC system, and get used to the system, programming and other DCC-isms.
Of course, you might be like me. I pulled my old DC trains out of a long slumber in the attic. I set up some track, and planned to build a DC layout and convert to DCC after a while. A financial windfall caused me to buy the DCC system a bit ahead of schedule. I installed one decoder, disconnected the DC system and powered up with DCC for the first time. Before the night was over, I had removed the DC power pack and put it in a box under the layout, never to connect it to a track again.
It takes an iron man to play with a toy iron horse.
Yes, I already am able to run the entire layout on one power pack by following Crandel's suggestion and if I understand you correctly, I would physically remove my two current power packs and replace them both with one DCC power supply which would power the entire layout. This would mean I would have to have all the engines converted at once. I have 14 locomotives. Also, as soon as I make the switch I set about the task of troubleshooting the electrical system, not being able to run any trains for the entire time.
My addition includes a fair sized classification yard and several industries so I am looking at having to purchase 20 to 25 turnouts. So here are a few more questions:
1. Is it possible to replace power pack A with a DCC power supply and leave power pack B attached as is? Then I could convert the locomotives 2 or 3 at a time and still be able to run the others on pack B (not simultaneously, of course). I realize I would have to be very careful never to let the converted engines run into a DC block - couldn't I simply turn off power pack B when running DCC? This would also give me time to debug the DCC system.
2. My original layout consisted of Atlas Code 80 flextrack and (mostly) Peco turnouts. I like the look of Code 55 track and can get it online at a reasonable price. What are your recommendations along these lines?
Thanks very much for your help so far.
Peter
Crandel is correct.
If the layout is wired with Cab control but uses a common rail, you should disconnect all DC power packs. Then just connect your DCC system to cab A and set all your block switches for cab A. I have converted a former DC cab control layout to DCC in just that way. I didn't have to change anything else.
I also think that because your locomotives are 5 years old or newer, you shouldn't have any problems converting them. I use TSC decoders for all of my Club N scale locos and really like them. The DCC conversion photos on their web site are a huge help and they will guide you step by step.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
As a general rule, yes, and the way to do the conversion is simply to close all the circuits/blocks/toggles so that the power supply can actually reach all the rails simultaneously. You want no open blocks, but you still need to handle phase reversals properly the same way you do for reversing loops or turning wyes in DC. That is, there must still be the gap at the best place, and the phase reversal (some call it polarity reversal because it's easiest to remember for those still in DC) must still take place at one end to prevent the same problem....the short.
Most find their non-insulated frogs to be trouble-free if their rolling stock wheelsets are properly guaged and the turnouts themselves are of good gauge, condition, and quality. You can still get the problems with power routing when you get such turnouts at the ends of the same siding, and in that case you still need the one pair of gaps at one of the turnouts. If your wheelsets make contact with the point rail that is not of the right phase for the type of turnout and the way it is thrown and routes power, you can get a short. But it really depends on several variables, and the idea is to just go ahead and isolate the frog entirely and provide gaps to keep the wheels from causing shorts.
The locomotive conversion is something I have never done, so I will leave that to others who can counsel you as to what you will probably have to do. Sometimes just getting new locos is at least a partial answer in the case of especially difficult engine conversions.
Crandell
The big question is, can the locos be fitted with decoders? Most Atlas and Kato of that vintage should have a board replacement decoder available, althouhgt it often is not simple plug and play. Go to the TCS web site and look at their decoder installs and pick out your locos. Older ones in you range, and even older ones, will almost certainly require frame modifications to fit decoders, the newer they are, the more likely it is the wiull be relatively easy to convert.
http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/N_Scale/N_Search/search.html
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I have a 30-year old N scale layout that I am expanding and upgrading. It is currently wired for DC dual cab control. Some of the turnouts are insulfrog and some are electrofrog. Most are Peco but some are Atlas. All my locomotives are Atlas or Kato, but most are 5 - 15 years old. My question is: is it possible to convert the layout to DCC or should I just keep it as is? Or my question probably should be, how do I go about answering this question?