LC+ Mikado loses speed control

I don't have a Mikado, but it sounds like the speed (tach) sensor isn't reading reliably.  On some locos, Lionel affixes the flywheel to the motor shaft with a tiny Allen screw.  If you have repair skills, you might try removing the shell.  Make sure that the flywheel is secure on the shaft, and hasn't rubbed through the insulation on any wires.  Another possibility is some kind of mechanical bind, but I can't imagine why that would ever "settle down."

A lot of folks love speed control, but a properly geared conventional loco does just fine, and there's a lot less to go wrong.  If you do find out what's causing your issue, please let us know!

I've had this problem with my LionMaster T-1.  It's visiting Gunrunner John for a fix.  Mine would surge when the train was on a grade. 

Jon

Yes, but Jon's issue with the LM T-1 Duplex is a bad motor, and I haven't been able to find a replacement!

The issue with the LC+ locomotive is likely to be the tach sensor, flywheel, or possibly something silly like loose screws on the gearbox.

Thanks John,

It is 103.6 F right now.  Too hot for old men.  I'll send my wife after the locomotive and check it in the cool of the big house.  

I will report my findings when I come to. 

I found the gremlin!  It was one of those nights when I couldn't sleep.  The train building was still too hot.  I got the remote to my LC+ and took it to my air conditioned radio room.  I looked up the FCC registration number as seen on the back of the remote.  Of course, the number is assigned to Lionel.  I discovered their frequency range is 2.404 to 2.476 GHz.   I set my spectrum analyzer for 2.2 to 2.6 GHz and operated the remote.  I had a good "on" signal but the train speed signal was erratic, just like the train speed.  As good as a finger print.  So, the speed control problem is in the remote.  To be exact, the speed pot is bad.  With a victory scored I slept well.  Today I will disembowel the remote.

Have y'all had to repair/replace your remotes?  More to follow.

Before you take the remote apart... You could further validate your findings by running the loco conventionally (if you have a variable transformer.)  If your theory is correct, it should run normally under transformer control.

Well, the remote is very easy to take apart, so I'd just shoot the pot with some contact cleaner and see how it does.

Thank you both,

My locomotive runs correctly in conventional mode.  I feel confident now.  This is the kind of problem I often encounter with my antique ham radio equipment.  I read somewhere that Lionel produced a RF controlled controlled set in the post war years.  I'll bet that a hoot to keep working.

Bill

gunrunnerjohn posted:

Well, the remote is very easy to take apart, so I'd just shoot the pot with some contact cleaner and see how it does.

I've got one somewhere that I tried to take apart. The speed wheel knob wouldn't come off. It should pull right off,  correct?

Yep, just pulls off.

Yeah.  Mine must have been stuck.  Started to pull the potentiometer out of the board.    Somehow I ended up with a second remote so I never pursued taking the first one apart.

I just took one out and yanked off the knob, they're just a press fit.

All is good now.  The train room is still too hot, so I used my spectrum analyzer again.  It looks much better.  I tried to take a picture of my computer screen without luck.  I've got to get air conditioning for my railroad.  Tonight, when it cools off I will test on my layout.  If anyone else has this problem, remember that a little tuner cleaner is good and a little more is bad.

GUNRUNNERJOHN, thank you once again.