I hope to try this conversion myself. I’ve done one install of an NCE D408SR. Any suggestions for decoders (power and sound), speaker, connectors, and/or lessons learned on wiring?
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I have a Weaver PRR 0-4-0, practically same vintage. I did not put sound in it, but it did not require a high amperage decoder. I used a Digitrax rated at 2.0 amps stall, and 1.5 continuous.
Test it on your bench on straight DC. I usually set it upside down in a foam cradle and connect leads. I put a meter that will read up to about 10 amps in series to read the amperage. I run it at 12 volts or max on DC transformer and hold a block of wood against the drivers to create a load and see what it draws as it is slowed down. Mine stayed down around 1 amp all the way to a stall. So I could use any decoder rated at over about 1.0 amp - I wanted about 1.5,
As for speakers, I have just used what I could get that fit rated at 8 ohm resistance. The decoder mfg sometimes recommends their own speakers to match. A really neat thing to do with a steamer which I have only done with one so far, is to put the speaker in the front of the boiler under the stack rather than the tender like many HO locos. This puts the sound right where it should be for a steamer.
I absolutely like to use a plug connection between the tender and loco for when I have to take it off the track. I can't handle it hard wired like many HO guys do. So depending on where the decoder and speaker are located plus the tender light, I find a plug/socket combination that has enough pins to handle the connections. If both the speaker and decoder are in the tender you need 5.
On many of my steamers I have been able to fit the decoder into the boiler over top the weight. That reduces the connections to the tender a lot.
I suggest a keep alive circuit (NCE medium "No Halt" works well for O scale). On my 2-8-0 I reversed one of the tender trucks. I can't remember if it was to get 4 wheel pickup from one rail or if I wired it to get pickup from the both rails on the tender. Also if it has a chuffing unit remove it to improve slow speed performance. On the 2-8-0 it was one screw to hold it in place.
https://ogrforum.com/...0#158111058982118820
thanks for the suggestions. Still wondering what decoder(s?) might be right… seems like some (most?) sound decoders come preprogrammed for specific locos. Assume the vendor might recommend /sell speaker and connectors.
https://ogrforum.com/...6#158111058988547876
Jim, thanks for the suggestion… hadn’t thought about the keep alive.
To choose a decoder, you still need to know what current (amps) the loco draws. You don't need this super fine, just need to know less than 1 amp, 2 amps or 4 amps etc.
I have seen a line of decoders, I think Soundtraxx that has decoders listed as "small, medium, and large" steamers. I don't know why size of the prototype would change the sound other than volume.
The big thing that would change sound is number of cylinders I think. A 3 cylinder loco would sound different than typical two cylinder. An articulated with 4 cylinders would be different.
there are probably some subtle differences for a Compound. But compounds did not last long.
The decoder for this in my opinion would be something for a 2 cylinder, small or medium size steamer.
