OK.  Thanks.

Nothing special.  An R/C Big Hauler running around my track which is in desperate need of some weeding.   https://www.youtube.com/watch?v=x0m20_JO2gk&feature=youtu.be

Yes, very nice indeed.  I am about to try that conversion as well.  I am curious what battery you used and also why you used NIMH rather than Lithium.  I'm thinking Lipos are generally smaller.  I don't remember if Crest has a low voltage cut-off, but you can buy Li-ion battery packs that have PCB protection.   I am planning on using a 3S Li-ion which is rated at 11.1 volts.  I would love to see a photo or schematic of your conversion.  Thanks.

Craig

I have several older Big Haulers.  Every one is missing what I assume are small plastic bells that fit in the plastic wishbone bell holders.  What I see in parts are what look to be much more sophisticated multi-piece metal bell components.  Those are overkill for my inexpensive entry-level locos.  Any suggestions for finding the simpler replacement bells.  Since they seem easily lost, I would probably glue them on if I could find them.  Thanks.   

OK.  Thanks.  It appears that Bachmann works in mysterious ways.

Hi Tony.  I think I understand what you are saying though I am not at all familiar with the terms "Superhet" or "Digital Proportional Signal."

Here in the US as I understand it there are six sub-frequencies in the 27 MHz band that are used for R/C communication.  The sub-frequencies range from 26.995 MHz to 27.225 MHz.  Each sub-frequency is capable of carrying (at least) 2 channels of information (e.g. steering and throttle) between the Tx and Rx. Each of these channels carries information that can be interpreted by an ESC as left/right in degrees of turn and forward/reverse in degrees of speed. 

I believe you are saying that the Bachmann loco receiver does not distinguish sub-frequencies and further is "latching on" to the information that informs the motor control to reverse?

Hi Wade.  I tried it in all sequences.  With the transmitter on, either before or after the loco, the train runs in reverse.  The trim did help to get top speed in the neutral steering position.  The loco does as you say - running full speed forward - with the transmitter off.

The transmitter that is designed to operate the loco can run in forward or reverse.  Somehow the signal from my 2-channel 27 MHz pistol transmitter is interpreted by the loco as reverse only.

I also have run R/C cars, Sleeping Bear, but not as long as 12 years, and I have almost exclusively used 2.4 GHz.  I believe you are right about the channel usage.  With an R/C car the throttle control can be used to run the car forward or backward (with the ESC programmed that way) - and that is all done on one channel (ch. 2 with 27 MHz).  Steering (on ch 1) does not have to be programed as the servo seems to understand how to respond to clockwise and counterclockwise manipulations.  I'm not sure how re-wiring would make a difference as I think the response of the loco's motor control is pre-programed to respond to signals from Bachmann's proprietary transmitter that are somehow different from a "regular" R/C 27 MHz transmitter.  I certainly could be all wrong about that.

As always, thanks for you comments.  It feels like I am a step closer to understanding with each comment.

Well, success - at least partially.  I made a power cable from a 4-pin computer disk drive cable with the 4-pin connector shaved a little to fit the receptacle opening in the loco and a male Dean's connector on the other end (wired as per Wade's diagram).

The 4-pin plug seems to be fine.  I connected a 7-cell 8.4v stick battery, turned the right switch on the loco to "on" and the wheels started turning.  It is a bit noisy.

Now for the Tx test.  All of the six crystals affected the locomotive although it seemed like #6 (blue) had the finest grain control.  I only have pistol transmitters in 27 Mhz and speed control was effected with the steering knob which I think is channel 1 on the 2-channel transmitter.  The throttle trigger (ch. 2) had no effect.  Maximum loco speed was at the neutral steering position going to full stop when the steering was turned to the peg (which direction  - clockwise or counterclockwise - affected the speed depended on the reversing switch on the tx). 

Here's the weird part (at least to me).  With the Tx turned off, the loco goes full speed forward.  With the Tx turned on, the loco only goes in reverse although speed can be controlled with the steering control (ch. 1) on the Tx.  Perhaps if the battery connection were switched, the opposite would be the case.  I'll try that.  But I don't quite understand why the direction would change with the Tx on and off.

For what it is worth I used a Tactic 27 Mhz pistol style 2-channel transmitter.

Well I might be able to try this experiment.  I found an old computer disk drive and pulled the cable from it.  One connector was 4-pin.  It took a little Dremel work to remove some of the alignment tabs, but now it fits into the receptacle in the locomotive.  

I soldered a Dean's plug on the other end, splitting the wires according to Wade's diagram.  I could not, however, figure out how the plug I have would orient to Wade's, so I may have things reversed pos to neg.  I don't think that should matter as long as there isn't a short.  It's 50/50.  As I have it now POS is going to the two right pins and NEG to the two left pins as you look at it from the rear of the loco.  If you see this Wade and I have it wrong, let me know.  Otherwise it will be trial by fire here in a few minutes.

Anyway, I'm charging a 7-cell 8.4 volt stick battery.  As soon as it is charged I'll see if I can get power.  Standing by are a 27MHz Tx and all 6 crystals.

Thanks for the heads-up Wade.  I sent the seller a message to ask if he might also have the R/C cable.  You never know.

Jerry, I wonder if the folks who tried the 27MHz stick transmitters tried all of the six channels.  Of course I have no idea if the Bachmann receiver is set to any of those channels, but since I have an old tx and all 6 of the crystals, I thought I would try it out.  It doesn't sound promising, but I will try it out and report back.

Thank you for the information on the R/C systems.  I'll check out G Scale Graphics.

As for the scale issue, no I am not sure.  While the difference between one meter and one yard may not be the most important to me, there sure are a lot of beautiful locomotives in the 1:20.3 scale.  The cost is a bit daunting, but I'm not looking at developing a big empire - if I went that direction,  a Consolidation for sure and maybe a Shay (and in my dreams a K27).  Right now I am planning as much "garden" as "railroad" in my garden railroad and have not started laying outdoor track.  Much to do with landscape work and building a pond and stream.  

I have purchased some R1 (24" radius) curve track, which I don't think I would be able to use with many locomotives, especially the larger 1:20.3 ones.  So I think I need to bite the bullet on that and make sure my track will handle wherever I end up equipment-wise.  

Y'all have been very helpful.  I appreciate all of the really good information you have given to me in a short period of time.

Craig

UPDATE:  And thank you Wade for the wiring information.  When I Googled 4-pin connector I did see a bunch that were used for connecting disk drives, so I think you are right about a computer connection.  Interesting if  Bachmann in the 90's would have used computer parts.

Loco Bill, I do have a metal-wheel "donor" if it turns out I can get the R/C Big Hauler to work.

Thanks to both of you.  Good advice about trying it out before investing more money.  I do have a bunch of 7.2 (6 cell) and 8.4 (7 cell) NIMH packs that I had hoped to try.

"At least you got the transmitter!!!"  Alas, no.  That is why I was wanting to try out a 27 MHz R/C transmitter with the different crystals to see which (if any) worked.

I was trying to get away on the cheap here - but without the cable it doesn't look like that is going to happen.  I don't expect it to be great or up to par with newer equipment, but there is some satisfaction for me in getting older stuff to work.

I sent an email to Bachmann service to see if they could help me with identifying the loco plug and how to wire it.  I'll see if they respond.

I am new to this, and after what I have read and what you have informed me, I do plan on picking up an Annie and putting in a modern RC system (Aristo Evolution or RCS) and the Loco Bill battery pack in the near future.  I'm having to make decisions on what to buy first.  I have a small ""test" loop set up in my basement for now.  I have figured out plans for a more satisfying outdoor circuit.  So I'm thinking, build the track before buying more expensive equipment.  But that track is pretty expensive too.

Again, thank you for your help.

Thank you Loco Bill for the great battery information.

I was looking at this:  http://www.hobbyking.com/hobbyking/store/__14843__Turnigy_5000mAh_4S_25C_Lipo_Pack_USA_Warehouse_.html  but it is pretty large (roughly 6"X2"X1 1/2").  Your battery box solution and GTL batteries look better to me.  It is smaller and it also has discharge protection which I don't thing the Turnigy Lipo has.

Well, I got my R/C loco in the post this morning.  I can't try it out right away since I don't have 6 D batteries.  I understood from what I had read that these locos also had a connector for a Nicad/NIMH battery pack.  I don't see one in the loco I bought unless I have to take it apart to get to the connector.  Maybe I do?  So buy some batteries or locate the connector.

UPDATE:  Now I see I need an adapter cable.  I wrote Bachmann parts, but don't hold out a lot of hope that they still stock it.  

OR if anyone knows what type of connector plugs into the loco that would be great.  It appears to be a 4 pin (not sure why) female connector.  I could then make my own adapter cable.  Or even if someone has the cable and could take a close-up of the connector, that could help.  Thanks.

Here's a picture:

Thank you both for your responses.  You have given me a bunch to think about.  More importantly using R/C seems a little clearer and more possible than it did before. 

The installation on the Aristo-Craft version does pretty straightforward.  I'll have to revisit the RCS site to compare.  The Aristo-Craft system does seem to be more sophisticated in terms of multiple train control, but may be more than I need for my simple layout.  I certainly do want to use sound - but either system may work for that.

Again thank you both for the very helpful comments.

As for the 27 MHz stuff I found the following on the Internet.

26.995 MHz - Ch 1 (Brown)
27.045 MHz - Ch 2 (Red)
27.095 MHz - Ch 3 (Orange)
27.145 MHz - Ch 4 (Yellow)
27.195 MHz - Ch 5 (Green)
27.255 MHz - Ch 6 (Blue)

"In many toy-grade vehicles the specific channel within the 27MHz range is not specified and unchangeable making it more likely that two or more 27MHz vehicles operating in the same area will experience crosstalk or interference. The most common fixed frequency for 27MHz toys is channel 4 (yellow) at 27.145 MHz. RC toys with selectable bands (usually 3 or 6) generally have a selector switch on both the vehicle and the controller that let the operator select a different band or channel (designated by letter, number, or color) so that two 27MHz toys can play together."

The channels are different in Australia and in the UK, but I would think that Bachmann would have to use the US standard for locomotives sold here.

I hope to get an R/C Bachmann Loco by this weekend and will let you know how my testing goes.  From what i understand, the receiver and speed control are both on the same board so it might be difficult or impossible to upgrade just the receiver to 2.4 GHz.  Also they would not have a lipo cutoff circuit, so would be limited to Alkaline, NiCad or NIMH batteries.

I am very interested in your conversions.  Electronics made for R/C cars - especially ESCs - seem like overkill as far as motor capacity while only handling 2S or 3S lipo batteries (11.1 V max).  The most promising source for large scale trains that I have found is Remote Control Systems in Australia - but still, even with the Planet Tx and Hobby King lipos it looks like well over $100/locomotive.  What system did you decide upon and how difficult was the conversion?  Thanks.

Thanks for the information.  Pioneer it is then.  I do have crystal for all of those frequencies.  It is outdated stuff as nearly everything of value is 2.4 GHz these days.

I am really surprised that one of the major G scale manufacturers doesn't offer a 2.4Ghz and Lipo battery option.  I'd guess the reason is that it would not be compatible with DCC and other favored operating systems, and you would need a transmitter for every train.  So I guess that won't happen.  

R/C just makes more sense for me so it is either make an old Bachmann R/C/ loco work or convert using one of the available aftermarket systems that are just a little more money than I want to spend.  If I convert it would definitely be to a 2.4 GHz system.

My belief is that those six channels are what were allocated by FCC for the 27 MHz frequency but I sure could be wrong about that.  Maybe they all will work as Bachmann's note indicates a 27 MHz loco can be operated at the same time as a 49 MHz loco, whereas vehicles with the 6 different 27 MHz crystals can be independently operated at the same time.  

I will report the results,  I should be getting a loco in the post pretty soon.