Works in Command but not in Conventional

Turn off the command base, it thinks it's in command mode.

Yes, Like gunrunnerjohn said, If the track is connected to the Command Base, the engine will read it as TMCC powered because it is TMCC equipped. A TMCC equipped engine will think it's in command mode if the Command Base is attached to the track.  If you power up to 16 volts + on the track, it will operate as a command engine.  To get a command equipped engine to operate as fully conventional, you have to disconnect the Command Base from the track.

I did install a model 400 to replace my Trainmaster 135 watt unit while the engine was back to Trainz for repairs.  I used to simple switch the Trainmaster from Conventional to Command using the slide switch.  I thought the model 400 could switch by pressing the combination of either the "L" or the "M" button and then "SET".  I will try just unplugging the commnad base this evening when I get home.  Boy that would be a easy fix!!!

It will switch it to variable voltage by pressing M-but the command signal is still pulsating through your tracks, telling any command equipped engine 'I'm right here for ya'

Thank you and gunrunnerjohn for the help.  You would think an electrical engineer could figure this out on my own.

It's the simple stuff that always gets you.

I disconnected the power from the command unit and could not get the CAB-1 to vary the track voltage so I reconnected the power and disconnected the DB-9 connector that attaches to the 400 watt unit.  Same result: no CAB-1 control of track voltage.  So what am I doing wrong?

I think you misunderstand.  I was assuming you were running the conventional stuff using a standard transformer, not from the CAB1.  If you're using the CAB1, why not run it TMCC?  If you're trying to use the CAB1 and the TPC to control track power, obviously the command base has to be connected.  I don't know of a way to run that locomotive in conventional mode with the command base active, it's seeing the command signal and going into TMCC mode.  Just run it as a TMCC locomotive.

I undestand and now agree.  I'm going to guess that if I just had my Lionel "Z" type transformer and no TMCC stuff at all, I would be able to run the 28052 N&W locomotive in conventional mode.  I love my BAB-1 and the ability to watch my trains from anywhere on the layout.

Now you have a new problem, you can't run a command engine in conventional with a Command base hooked up and you can't use a TPC without a base. Hook your wires from the transformer directly to the track and unplug your base. Now you can test your engine in conventional. Now you know why TPC's are for running conventioal engines.

Neil

Gunrunnerjohn is correct. A TMCC locomotive can only run conventionally with transformer control. Trying to run it conventional off a TPC will adjust track power but the engine will always see the TMCC signal and go to TMCC mode. You could run it and all your other post war engines from a CAB1 and Powermaster in conventional.

What am I missing here?  To run a conventional locomotive with a TPC, you simply disconnect the wire from the thumbscrew terminal on the Base, thereby killing the TMCC signal to the track.

Good point Dale, I wonder if that's a combination that hasn't been tried?  I'm forgetting the TPC doesn't need the signal to function, since it's connected directly using the serial cable.  My TPC's are in the closet, so I am not reminded how they connect.

That did it.  I disconnected the single wire that supplies the TMCC signal to the track.  Now everything conventional works.  Thanks guys.

Thank Dale, we were all being dense!

You can also do this with a power master since the CAB-1 talks directly to the power master without the Command Base.  I just leave the Command Base unplugged and use the Power Master/CAB-1 to vary voltage to the track.  G

Really-that's interesting.  I thought you needed a Command Base to run through a Powermaster or TPC to run in conventional with the Cab1.  I have been meaning to set up my dad's std gauge train from the 40s and run it with a Cab1.  I thought I needed a command base to do it and was considering buying an extra one for projects like this.  I already have an extra powermaster.  Thanks, I'll give it a try.     

The PowerMaster is unique that it receives commands directly from the CAB1.  Actually, the CAB1 and PowerMaster were developed before the TMCC Command Base as a system.

Sweet!  I'm going to give it a try next day or so-maybe tonight.  That makes sense, because that's what I told Kenai to do... 

So this is all I need to run with this old girl with a Cab1---we'll see---job opportunity..

William,  If you are using the 1033, you also need the adapter cord that connects to the 1033 and has an inline fuse.  The other end has the correct plug to connect to the power master.  Then you are SET!  G

Oh yeah- the plug to the powermaster.  Thanks for reminding me GGG.  Going to get back to this later.  I'll just ask quickly if I may, is that the plug that I originally used with the powermaster?  I should still have 2 of those.

Completely disconnecting the ground wire from the screw terminal on the command base is the only way I can get the signal to not confuse my Lionel 28052 locomotive.  If I connect any wire, shielded or not to the command base and also connect a similar wire to my ground terminal system but leave them disconnected, the 28052 won't run in the command mode.  I was hoping that I could simply connect these two wires together (using a male and female 1/4" audio plug and jack, when I want to run my 28052 in command mode....but Nooo!!  I guess the wire connected to the command unit's screw terminal is a sufficient antenna to send the signal to the 28052 handrail antenna.

the only ground the command base gets is from the wall plug.

Okay, wrong term.  The wire that goes from the command base screw terminal that is connected to the outside rail(ground) is what I am talking about.

don't understand this statement "I was hoping that I could simply connect these two wires together (using a male and female 1/4" audio plug and jack, when I want to run my 28052 in command mode".

there is only one wire that I connected to the outside rail from the legacy command base.

You should be able to disconnect the wire from the Command Base at the CB with a plug/jack combination, but the disconnect must be very close to the base so that there is no secondary antenna via the wire attached to the thumbscrew.

How long is the wire that you currently have connected, and is it bundled in with any track power wires?

Thanks for understanding my engineering dilemma.  I was hoping to be able to simply have two separate short wires that I could plug together when I really wanted to use my 28052 in command mode.  I found that even a 1 foot length of shielded audio wire connected to the command screw terminal was enough of an antenna for the engine to pick up the signal.  I had another longer similar audio shielded cable connected to my outside rail system.  Of course when I plugged them together, the engine would run in command mode when I set the system for a constant 18 volts on the track.  But when I disconnected the two shield audio cables, and set the system to conventional mode, the engine just sat there.  I am sure that it was still picking up the RF signal from the 1 foot piece of audio cable.  Anyway, I will have to connect and disconnect the regular old wire to the screw terminal on the command unit when I want to run the 28052 in command mode.

Do you have both the shield and the inner conductor attached to the thumbscrew?

Wow????

Wasn't there some concept somewhere somewhat like 'all you have to do is connect one wire to the track and you're running in Trainmaster Command Control !'

Or did I get lost somewhere. 

Works for me that way.  We're not talking about just connecting the command base, but rather switching the signal on and off.

As far as disconnecting the wire, you could always use a relay to remotely disconnect right at the base.  If you use a SPDT relay and have the NO side shunt the lead to track common through a .1uf capacitor, that should kill any signal that might leak through the relay.

That is a great idea Gunrunnerjohn.  Much more elegant than using an aligator clip to attach the wire to the command base lug!!

Well, it's more expensive and more trouble to do it my way, but it is more elegant.  You could even have a pilot light that says TMCC or Conventional for the switch to the relay.

Why isn't shorting the input with a cap a good idea? 

Failing that, how about switching in a LC filter with a choke?  High impedance to the RF, and a cap to shunt anything that escapes to ground.  It's really hard to believe we can't kill this signal without any damage.

What "input" are you shorting, and to what are you shorting it?

Sorry, I meant output.

Let's recap:

The object of the exercise is to simply switch the TMCC signal on or off without powering down the base. 

If I switch in a capacitor between the command base output and the ground wire from the outlet, I am effectively shorting RF the signal out of the command base.  I somehow doubt this will hurt it, but if there's a possibility of damage, I'd switch in a choke and the capacitor to accomplish the same thing but offer a higher impedance to the output TMCC signal to avoid any possible damage.

I haven't tried this, but I can't see why it wouldn't work.

What if you just unplug the Command base, or put an extension cord between the Command base plug and the power outlet with an on/of switch that is readily available.  Cut the signal from that direction instead of from Command base to track.  

I was under the impression that the base was required to run a TPC so that cutting power was not an option.  However, since he wants to run in conventional, he needs to cut the TMCC signal to the track.