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Installing a Decoder in a Bachmann GG-1

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  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, September 3, 2014 9:47 AM

 If the chokes and capacitors are bypassed just by plugging in the decoder, it would likely be a first for Bachmann. The capacitors in some models are mounted on the circuit board, on others they are directly attached to the motor terminals.

 The capacitors are in parallel with the motor - as such, they can be just clipped off. This is generally sufficient, as it takes a combination of coils and capacitors to filter certain frequencies. The coils are a bit more bother - they are in series with the motor power and as such cannot just be clipped off - the motor will no longer get power. If removed, a jumper wire must be installed in their place.

 Motor control seems to improve even with the cheapy old Bachmann motor only decoders, and most definitely with better quality decodes that have high frequency drive and BEMF, just by removing those capacitors. Some people have DC control systems that use a drive similar to the output of a DCC decoder - clipping the capacitors improves performance with these systems as well.

                             --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    July 2013
  • From: Northern New Jersey
  • 89 posts
Posted by Daywhitemtns on Wednesday, September 3, 2014 7:31 AM

gmpullman

I think the OP was just explaining that in some cases you need an 8 pin "riser" to get your decoder to clear some components that are on the board. I remember needing to do this on some BLI Blueline boards.

What I would like to know is if the Bachmann "choke coil" or is it a filter capacitor that they put across the motor leads gets bypassed? I seem to recall that Bachmann uses this wiring plan on all their HO engines to comply with some kind of FCC RF interference code and that it has some undesirable effects (IIRC Randy Rinker mentioned in a past thread) maybe messing up the BEMF?

I am presently installing decoders in a pair of Bachmann E-33 motors and I am scrapping the board entirely which is the prefered method for me.

Happy Modeling, Ed

 

In response to your question I took another look at the Bachmann board in the GG-1. It has two choke coils installed for interference suppression but I can't tell if they are bypassed due to the decoder installation, nor can I tell if the back EMF function is affected adversely by their presence - I simply don't know enough to have an opinion here. If you do scrap the Bachmann boards in your E33s, I'd like to know the results and if you feel a noticeable improvement resulted.

I should also add that the GG-1 body must be properly oriented on the frame - it cannot mount either way. There is a directional arrow molded on the motor cover on the frame and a corresponding directional arrow molded on the underside of the body's roof indicating the correct positioning.

  • Member since
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  • From: Northern New Jersey
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Posted by Daywhitemtns on Wednesday, September 3, 2014 7:00 AM

davidmbedard
Thick skin is an asset. I was hoping for pics....because I didn't gather what you were describing...that's all. Not everyone knows how to plug in an 8 pin socket.....they need a little guidance. Little things like determining pin one is difficult for some....and a mistery for those new to DCC .....this is where a picture can help the masses.

David B
 

Sorry that I wasn't more clear in my explanation. To begin with, I forgot to mention that an exploded view parts diagram is included with the GG-1 detailing its internal layout although I did download another one from the Bachmann website. After unscrewing the four #10215 screws located on either side of both pilot trucks on the bottom of the frame, the GG-1 body can be removed. The OEM 8-pin socket can immediately be seen at one end of the frame. Eight pin plug-in decoders or decoders with a harness and 8-pin plug generally have pin-1 marked with a 1 or a dot as an indication. The socket may have a corresponding mark although not all I've seen do. If you can determine the color-coding of the wires attached to the socket, note that following the NMRA protocol the orange wire (motor right) attaches to the receptacle for pin 1 while the red wire attaches to the receptacle for pin 8 (right rail). If all else fails, simply plug the decoder into the socket without regard to orientation and test it on the track. If the orientation is correct, the locomotive will move and the headlights will work properly. If incorrect, the locomotive will still move but the headlights will not work. In that case, simply reverse the decoder in the socket and all will be well. No harm will be done by plugging in the decoder with incorrect orientation.

I hope this is more helpful to you.

 

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Wednesday, September 3, 2014 6:50 AM

I bought the sound version.  I took advantage of a free shipping special at Trainworld and the seriously low price of about $150, as I recall.  I like the horn, in particular, as the engine itself is quite quiet.  The instruction sheet mentioned that the GG-1 had a reputation as a "widow maker" because it ran so silently and track crews sometimes failed to take notice.

Gigi has no problem negotiating 18 inch radius curves.  The trucks all track very well and I didn't have to tweak any of my trackwork on her behalf.  One of the crummy plastic couplers has already failed, so I'll be replacing those when I get to it, or when the other one fails.

Like other Sound Value decoders, this one does not support CV5 and CV6, Vhigh and Vmid.  Instead, similar functionality can be found in CVs 63 and 64, listed as Starting Voltage and Maximum Motor Voltage.  These are listed online (Google Sound Value Decoder CV) but not provided with the in-package documentation.  I had to play with these (and CVs 3 & 4, acceleration and deceleration) to get a smooth start.  As delivered, the first few steps (at 28 step mode) were very jumpy, and speed step 1 was already too fast.

 

It takes an iron man to play with a toy iron horse. 

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Tuesday, September 2, 2014 11:41 PM

I think the OP was just explaining that in some cases you need an 8 pin "riser" to get your decoder to clear some components that are on the board. I remember needing to do this on some BLI Blueline boards.

What I would like to know is if the Bachmann "choke coil" or is it a filter capacitor that they put across the motor leads gets bypassed? I seem to recall that Bachmann uses this wiring plan on all their HO engines to comply with some kind of FCC RF interference code and that it has some undesirable effects (IIRC Randy Rinker mentioned in a past thread) maybe messing up the BEMF?

I am presently installing decoders in a pair of Bachmann E-33 motors and I am scrapping the board entirely which is the prefered method for me.

Happy Modeling, Ed

  • Member since
    April 2004
  • From: Ontario Canada
  • 3,574 posts
Posted by Mark R. on Tuesday, September 2, 2014 11:34 PM

I thought the review was well written. I understood exactly what he was describing, but then, I'm well versed in DCC installations and knew exactly what he was referencing with the spacer plug.

That being said, there's going to be a LOT of people who are not very knowledgable in DCC installations that couldn't get a mental image of that no matter how hard they try.

As they say, a picture is worth a thousand words.

Mark. 

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
    July 2013
  • From: Northern New Jersey
  • 89 posts
Posted by Daywhitemtns on Tuesday, September 2, 2014 8:36 PM

Gee, and i guess if one needed a pictorial as to how to plug a decoder into an NMRA socket in a Bachmann GG-1, one could go to the Bachmann website and bring up the exploded view diagram of the DCC-Ready GG-1 showing the location of the OEM socket.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, September 2, 2014 5:57 PM

 Hmm, and all this time I should have known, those install pics on the TCS web site that show how to fit decoders in a huge variety of various scale locos are just not necessary  </sarcasm>

               --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    October 2006
  • From: Western, MA
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Posted by richg1998 on Tuesday, September 2, 2014 3:57 PM

I agree with David B.

A good review would have pictures to help others who might like details. This is a model railroad community.

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.

  • Member since
    July 2013
  • From: Northern New Jersey
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Posted by Daywhitemtns on Tuesday, September 2, 2014 1:07 PM

[quote user="davidmbedard"]Reviews sans pics are lacking something......

David B

I disagree!
  • Member since
    July 2013
  • From: Northern New Jersey
  • 89 posts
Installing a Decoder in a Bachmann GG-1
Posted by Daywhitemtns on Tuesday, September 2, 2014 12:19 PM

Since I don't like sound and prefer to install my own choice of decoder, I purchased a DCC-ready Bachmann GG-1. It comes with an NMRA 8-pin socket. Once the Bachmann plug-in board, which enables operation of the locomotive on DC is removed, it's a simple matter of plugging in your decoder of choice. Because of limited space around the socket area, I decided to use a Lenz Silver Direct decoder which plugs right into the socket without the need for a separate harness and plug. However, due to the presence of an interfering plastic wire keeper adjacent to the socket, it was not possible to seat the decoder all the way down. This was easy enough to fix by first installing an NMRA 8-pin connector (combination socket/plug) into the OEM socket which raised the decoder high enough above the keeper so it would sit flat and level. These connectors are available from Tony's Train Exchange, or other sources, for a nominal fee.

With the decoder installed, the locomotive ran smoothly throughout the speed range from the slowest crawl to maximum speed. Acceleration and deceleration delays were quite appropriate on my layout without having to adjust CV3 and CV4 but of course these parameters are easy to adjust to one's taste.

All-in-all a nice-running model. Bachmann specifies a 22" minimum radius and with my 24" minimum radius curves the model tracked perfectly and looked good while doing it.

While I was at it, I replaced the OEM couplers with Kadee "scale" #158 types and painted the pilots, pilot truck and driver sideframes PolyScale RR Tie Brown which pretty closely matches the appearance of the undercarriage of the prototype when I could still see the prototype, and in most of the photos I've seen. Also, it gets rid of that horrible plastic sheen.

For those of you who want a GG-1, IMO this is a good-looking, excellent running model at a quite reasonable price.

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