Skip to main content

I have three new Legacy steam locomotives, and all of had a common issue.  Crossing certain switches cause the sound to drop out.  No problem I thought, I actually designed a product to take care of this specific issue with Legacy steam locomotives, the YLB - RailSounds Battery Replacement (RS-Lite).  So, I popped open the tender and with my YLB in hand, I prepared to fix this annoying issue.

SAY WHAT???  There is no battery connection for the new boards!

Lionel RSL4 Sound Dropout Fix N1

After a little detective work, I found an interesting configuration for the filter caps on the board.  First off, they had thru-hole caps on a mostly surface mount board.  I suspect that component shortages may have dictated the change, I know I can't buy a 220uf 35V SMT cap to save my soul!  There are two caps on the board, the negative terminals are common, but the positive terminals are separated by a diode.  Now, that's a somewhat curious configuration that I haven't seen before, but I'm guessing it was to prevent the second cap from being discharged back through the track connection, it would be interesting to see the whole circuit drawn out.  Not sure exactly what was intended, but I decided that was a good place to tap into the raw power.

Lionel RSL4 Sound Dropout Fix N2

By adding a 2200uf 35V cap, I was able to increase the sound hold-up time to several seconds, more than enough to transition the brief track power interruptions of slow running over a switch.

Lionel RSL4 Sound Dropout Fix N3

I used a small piece of double-sided foam tape to secure the capacitor inside the tender, job done.  At about ten minutes for each of my three new Legacy engines, I had this project all wrapped up in half an hour!

Lionel RSL4 Sound Dropout Fix N4

The after effect of adding the fix, before the fix the sound would drop out at slow speeds over either of the double slip switches or the curved switches on the layout.  Now I can go around as slow as possible and no sound dropouts.

Attachments

Images (4)
  • Lionel RSL4 Sound Dropout Fix N1
  • Lionel RSL4 Sound Dropout Fix N2
  • Lionel RSL4 Sound Dropout Fix N3
  • Lionel RSL4 Sound Dropout Fix N4
Last edited by gunrunnerjohn
Original Post

Replies sorted oldest to newest

Without spending a lot more time tinkering and tracing, I couldn't figure out if I could find a place to use a supercap.  However, the large conventional cap on the raw rectified power gives me a bit more than two seconds of sound.  This seems sufficient for most brief power interruptions running over switches.  I prefer this to the solution I was considering, adding a tether between the locomotive and tender to bring track power over and share the rollers.  This keeps the simple drawbar connection intact and solves the sound drop-out issue.

John, That certainly was a quick and easy fix once you saw there was no place for your YLB.  For sure everyone is dealing with component shortages.

Arnold, My guess is if you put a legal document in front of us, I wouldn't understand any of it!    Come to think of it, I passed my FCC Radiotelephone License exam 45 years and a couple month ago.  We were still dealing with vacuum tubes then.

@Mark Boyce posted:

John, That certainly was a quick and easy fix once you saw there was no place for your YLB.  For sure everyone is dealing with component shortages.

Arnold, My guess is if you put a legal document in front of us, I wouldn't understand any of it!    Come to think of it, I passed my FCC Radiotelephone License exam 45 years and a couple month ago.  We were still dealing with vacuum tubes then.

Mark: About the same time you were getting your license, I was learning the hard way NOT to ever tell anyone that you knew how to repair (tube) TVs cuz EVERYBODY had a broken one somewhere!

John: I assume you tied your big cap to the 2nd cap on the board? I wonder why the diode wasn't added before the 1st cap?

George

Last edited by GeoPeg
@GeoPeg posted:

John: I assume you tied your big cap to the 2nd cap on the board? I wonder why the diode wasn't added before the 1st cap?

There's a bridge rectifier at the input of the power to the board.  That's normally all you see for a power supply, that produces DC of the proper polarity no matter what comes in, AC or DC.  The exact purpose of the diode between the two caps is a bit of a mystery to me, I can only imagine it was to prevent the cap from discharging back through the input circuitry, not sure exactly how.  I'd love to see a schematic of all the power input circuitry.

@William 1 posted:

Just throwing it out here, for some guys who don’t want to open up their engine, ERR makes a relay that give track power to the middle rail depending on direction and it works really well to not lose power to the engine when crossing a Ross switch.

All my longer curved switches, and the double-slip switches, have the DZ-1008 relay to energize the dead rails.  That's obviously not enough for close coupled rollers on many tenders.  The only cure I know of is opening them up and applying a fix similar to this one.

@GeoPeg posted:

Mark: About the same time you were getting your license, I was learning the hard way NOT to ever tell anyone that you knew how to repair (tube) TVs cuz EVERYBODY had a broken one somewhere!

John: I assume you tied your big cap to the 2nd cap on the board? I wonder why the diode wasn't added before the 1st cap?

George

George, I know what you mean!  I wanted to tell everyone I was a janitor 😆

Add Reply

Post
OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
330-757-3020

www.ogaugerr.com
×
×
×
×
Link copied to your clipboard.
×
×