New to DCC and I want to add a decoder no sound to my new switcher I bought last year. The box says DCC ready so I assume the motor is isolated. It will accept 8pin or 9pin decoder.
What is the difference between 8 and 9? My local hobby store only sells 9 pin decoders and they were out of stock. I just want a motor only decoder.
I just purchased the MRC decoder doctor so I can read the CVs on my DCC locos, (I'm using the Tech 6) and it has a NMRA 8pin socket for testing decoders before install. I'm confused. So 9 pin is not NMRA compliant? Can I test a 9 pin decoder in a 8 pin socket?
Pat Bandy
Pat,
Back in the Dark Ages(early 90's), decoder came with a 6 pin or 8 pin plug/socket. Most decoders in the US followed the NMRA 8 pin format. Since electronics moves must faster than the rest of the world(NMRA included), the 9 pin JST connecter arrived. This is much more compact and allows easier wiring in a body shell. Your Athearn RTR loco has a 8 pin connector and a harness with a 9 pin JST connector - You can use either decoder type. Most non-sound decoders have a JST connector on the end of the decoder and a wire harness or just wires.
Many of the new sound decoders have the 21 pin harness with 6 function outputs and speaker output. These are all NMRA complient, but there is a Euro version of the 21 pin that does not have the current driving capacity of the last 2 outputs that the NMRA version has.
Confused even More? The electronics industry changes faster than any other!
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Yes, 9 pin is NMRA compliant. There are multiple connector sizes that are part of the DCC standard.
9 pin connector is generally on the decoder itself, no wire harness. 9 pins allows for the track pickups, motor outputs, 4 functions, and the common wire. The 8 pin typically has the track pickups, motor output, 2 functions, and the common - the 9th pin is not connected so that if you plug the 8 pin plug backwards, nothing gets damaged. The 9 pin connector is physically keyed so you can't plug it in backwards.
You would need a 9 pin to 8 pin harness to hook a 9 pin decoder to the Decoder Doctor. Most "8 pin" decoders really are 9 pin decoders that come with a wiring harness with an 9 pin plug at the other end. And many 8 pin decoders have way too much wire for many installations, so you need to either cut it short or find room to tuck it away in the loco where it can;t get caught in any moving parts. TCS sells many different lengths and orientations of 9 pin to 8 pin.
On Athearn engines that come with both connections, they will have a dummy plug in the 9 pin connector to allow the loco to run on regular DC. This little board has to be removed no matter if you are plugging in a 9 pin decoder or an 8 pin one.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thank you Jim and Randy. Both posts were very helpful alltho Randy edged you out Jim! lol
Seems I will have to wait till Monday to get my decoder. I have four DCC locos with Soundtrax and I love them. The Walthers Mainline SD70 I discovered for cheap was just that, cheap. Only four sound functions available and what I've read so far, not much else I can do without replacing the decoder but that will be for another day.
Right now, I just want to get the switcher changed over to DCC.
TCS has very good motor control. PLug and play.
TCS cover quite a few brands. Non sound and sound.
Look at the below link.
http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Athearn/SW1500_DCC_Ready/Athearn_SW1500_DCC_Ready.html
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
I think I used a TCS T1 decoder in my SW 1500s, or possibly an NCE D13SRJ. I use the 9pin connection when there is an option between 8 or 9 pin. A NCE D13SRJ or TCS T1 should fit just fine.
Small switchers (Alco S and HH types) get the TCS 6pin MC2 decoder.