Converting Lionel Rail Sounds to DC operation

Easiest way is to run AC when operating this model by itself.  All your lights should still work in your cabeese and passenger cars.

Doesn't the Lionel system require more than just a transformer?  My MTH Hudson needs a special controller, and a factory reset.

Nope:  the 6-18030 is a conventional engine.  Pulls like a mule; it will climb a cliff with a heavy train (just keep the traction tires fresh).  Everything on the engine is DC, but it was designed to run on an AC layout, so there is a part of the electronics in the engine that converts the AC to DC.  It's part of the Electronic Reverse unit:  This is standard stuff for a can-motored engine in the Lionel world.  I do not know if it is possible to eliminate that portion of the board from the rest and keep the RS intact.

The Railsounds looks at the track voltage for DC offsets to trigger whistle or bell.  If you're running it on DC, it'll always be triggering either the whistle or bell.

AC would be a possible option if I was just running it at my home layout but I plan to take it to the club layout and they just run DC.  It did come with the early Lionel box that switches the rectifier polarity to control bell or whistle on AC operation.

The traction tires are long gone, those were removed when the wheels were turned down for 2 rail.  It's heavy, and I plan to add more weight, so I think it will pull fine.  It does run smoothly.

I thought the DC operation might make the bell or whistle on all the time, but I think it is triggered by a change event so it's off.  It may come on and stay on if the engine goes over dirty track, but on DC I couldn't get a peep out of it.

The whistle should be on all the time if the polarity is right.  The bell is triggered by a change, so as long as the power stays on, you have a 50-50 chance of the bell not ringing.

I think a conventional whistle tender probably would be.  This must be AC coupled or look for the change since it is not on when powered by DC.  I ran it quite a bit last night (on a test bed, not on track) and the whistle and bell do not come on and neither does the chuff on DC.  All work fine on AC.

Well, whatever works for you.   I don't get those results with a TMCC tender on the tracks here using DC.

Based on the accurate observations GunRunnerJohn, I need to modify my earlier statement that it is not possible to keep the RS electronics operative correctly when feeding the engine straight DC. 

Why not look into a DCC setup with a sound decoder?

At one time, running 2-rail TMCC was pretty popular, but it didn't survive the DCC onslaught.  You might try looking at the index of the early issues of O Scale Trains magazine for  articles on doing so.

I should have titled my post differently.  The 6-18030 Mikado came out in 1993 and is not a TMCC engine.  I realize you can control it with TMCC, but it pre-dates the actual TMCC equipped engines.  It has the early rail sounds, not the later rail sounds II and they are certainly not close to state of the art now.

I plan to run this frequently at the club I belong to and they are strictly DC, so DCC is not an option.  I understand how to install it if I wanted to go that way. 

The tender operates exactly how I described it on DC, I am an electrical engineer and have been designing and testing analog and digital circuits for 35 plus years.  I appreciate the suggestions and welcome anyone else's experience with this.  I will likely just make a new tender bottom plate and run this with DC and not try to use the rail sounds. 

Thank you all.

So when you said "retain some of the functionality" in your original post, were you referring to ability to trigger whistle/bell?  And if so what is your thinking on how that would be done with DC+ or DC- on the track at all times.

There are methods in the DC HO world to activate whistle/bell by fussing with interrupting the DC track voltage and such. 

With low-cost RC modules on eBay I'd estimate say $5 per channel for a simple FOB and receiver that could be patched in to the board where DC+ and DC- offsets are detected on your existing sound board to remote trigger the whistle/bell....seeing as you're an EE that is.

I was thinking of keeping the chuffing sound, it's not that bad, and trying to have it whistle when it first starts.  The problem is the varying track voltage, a bridge rectifier can fix the polarity.  There are options for the track voltage as well, just not sure I want to get that involved.

I was just surprised that it did nothing on DC so that's why I posted this, just to see if anyone had encountered this before.

You might look up Dallee electronics. I *think* they offer a sound solution to your query.

Do you know how DC offset is detected?  Seems you just need to cut a trace in that circuit...then install a R-C that inserts a one-time 5-second (or whatever) DC offset when power is first applied.

Thanks for the info on Dallee. I'd forgotten about them, and I think that might be easier.

Regarding the DC offset, no I don't know how they detect it on this tender.  There are a number of circuit cards stacked in the tender and I don't have a schematic.  One circuit card is dedicated to the reversing circuitry and there is an amplifier board for the sound.  I literally just started looking at it a day ago.  I'm inclined to leave it intact and set it aside then do my own sound if I elect to go that route. 

Thanks again to all that have replied!