switching to dcc

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B

bncity

New Member
I am switching to dcc and would like some help, I have 10 DCC ready locomoitives, most Athearn, with 1 Kato and 1 Atlas, and a dozen or so old blue box Athearns. For now I am just going to change the DCC ready ones. My question is what system works best for everyone, and what decoders do I want? Also, how hard would it be to switch the old Blue box locos over? I have done some soldering if that helps. If it matters, my layout is 10' by 25'. Thanks for any help,
Jerry
 
Hi Jerry,

Digitrax is a great DCC system. They make a variety of decoders to convert your locos. For conversions of your DCC ready Atherns, the http://www.digitrax.com/products/mobile-decoders/dh163p/ (6 out put functions) and http://www.digitrax.com/products/mobile-decoders/dh123p/ (2 output functions). For the blue box locos, they used to make a special decoder, though I can't seem to find it on their site...

Something you might consider is a few sound units. Sound will add much to your layout.
 


It's possible to convert an older model to DCC. Some are easier than others and if it is a good runner then it would be worth the effort. If it is a poor runner then I wouldn't bother with it. Sell it or give it to somebody for parts and buy something worthwhile to replace it.

DCC is a great addition to good equipment, but it won't make a Cadillac out of a Pinto.
 
The major problem would be with locos that have the frame electrically linked to the wheels on one side, and likewise connected to one terminal of the motor. You really need all the connections to be made via wires for DCC to be usable.
 
John P said:
The major problem would be with locos that have the frame electrically linked to the wheels on one side, and likewise connected to one terminal of the motor. You really need all the connections to be made via wires for DCC to be usable.
Click to expand...

I converted a Bachmann plus 4-8-4 J that had that difficulty it was a matter of cutting the brass clip that connects the motor to the frame then soldering the encoders power pickup to one side of the cut clip and the lead to the motor to the other side of the cut. It wasnt an easy install to do, but i did manage to get the encoder in the loco body rather than the tender.
You just have to work out a way to isolate the motor from the frame then make that conection through the decoder
 
I can't give too much advice on gear as I've only used a limited selection. I have NCE's power cab and the club has the pro cab version. The NCE system seems to work well, but I haven't used other DCC systems to compare it with.

I've got a bachmann decoder in one loco and a TCS decoder in the other. The bachmann decoder works much better than most people will tell you. It did take a lot time to run that loco in before it ran well. The TCS decode caused some problems until I turned the BEMF off. Lots of people rave about BEMF, so I am not sure what I am doing wrong.

My club has the Sprog II programing system with JMRI's decoder pro program on a computer. This allows programing the decoder through a windows interface which I find much easier than fiddling with a cab to do the programming. The progam track at the club is located at the computer and not on the layout. You'll need an isolated programming track, but many people have this on their layout.

I have had to rewire a P2K S1 for DCC. I found it pretty simple to add a wire to the motor avoiding a live cahssis. I also added lots of electrical tape just to make sure no electicial shorts could occur. Avoiding shorts, which destroy decoders, is why we need all that electical isolation.

The big difference between DCC and DC is the need for very clean wheels and track on DCC. We need a nice strong signal through the tracks, especially with sound. There is nothing more offputing than sound locos stalling, then restarting their sound. On board capacitors and a bus wiring system for hte layout with feeders to very length of track, helps here. Also turnouts are best to be rewired to ensure no power gaps. You might need to fiddle a bit with turnouts to stop any shorts that might occur there.

Hope that helps and I appologise for the contradictory report on decoder proformance. TCS and lokpilot are supposed to be very good while bachmann is supposed to be terrible, dispite my experience.
 
evil_ol_man said:
Here is a good question: is it possible to retrofit an older locomotive with DCC? or is it impossible?
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I have never met a locomotive that I could not convert to DCC. The issue with old locomotives is often the current draw of the motor. In this case one has to purchase special high-power decoders or remotor the loco.

Then it becomes a financial question as to whether the cost/effort of putting in the decoder is work more or less than just purchase a new loco which often run SOOOO much better anyway.
 
I was wondering about that. most of my blue boxes need more power to run than the DCC ready ones and I was curious if you could adjust that with DCC. Maybe I'll try one to see what I can do.
Jerry
 


The most important thing to do when converting older locos is to conduct a stall test, to see what the top amperage is thru the motor. If the stall amp rating on the motor is higher than the amp rating of the decoder, you'll be asking for problems. Otherwise the conversions of older locomotives, including Athearn BB's is straight forward.

To conduct a stall test, connect a VOM meter with one lead to the track and the other lead to the power pack. Set the VOM to register amps. Apply full power to the loco, and press down on it until the motor stops running. Quickly note the amp rating at its highest, and then cut the power. Do not hold the loco down for longer than 3-5 seconds as you could damage the motor if held longer.

Generally if the stalled amp reading is greater than 1 amp, then the motor needs replacing.
 
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Eric, the reason you can't find the Athearn BB harness, is they are no longer offered. You can make an "Athearn Harness" cheaper than you can buy one.
 
one more question, I have some signals that run off track power, will they be ok that way if I switch to DCC ?
Jerry
 
BN,

I'm at the point of considering jumping the DCC shark, also. I have a thread in the Electronics section on DCC and signaling, as its something that I want to include going forward. FWIW, I'm leaning towards NCE, over Digitrax, but am also considering one of the MRC Prodigy systems. I don't know if there's much difference between the NCE and Prodigy systems. FWIW, one reason I haven't converted to DCC previously, was that I have a huge number of locos from prior to 1998, and considered decoders for all of them to be to large an investment. Now I'm thinking that I'll probably limit the number of locos I convert to DCC, and just display the rest, or get rid of them. Its also concerned me about how would I fit a decoder into many of the older locos. I'd rather not eliminate flywheels, or have to become a remotorer. The one remotoring job I did years ago, wasn't completely successful, so I haven't tried much in that regard since.
 
bncity said:
one more question, I have some signals that run off track power, will they be ok that way if I switch to DCC ?
Jerry
Click to expand...

Probably not. Many older systems are not DCC compatible, esp if they utilize track detection like the old Twin-T system.
 
bncity said:
one more question, I have some signals that run off track power, will they be ok that way if I switch to DCC ?
Click to expand...
That would depend totally on the signal system. There are so many different ways to do signaling it is impossible to say. In general, I would guess not.
 
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