Need help identifying the common terminal for a Marx 1209 transformer

It doesn't really matter for your use but if you want to be technically accurate, the wiper is connected to the left post, so the layout common would be phased/connected to the right post.

Thanks for the help Rob!

OhB1 posted:

I have a Louis Marx 1209 transformer 50 watts that I want to use to run the accessory rails on my atlas track.  I need to identify the common terminal but the transformer is not labeled at the outputs other than "To Track".  I'm sure that if that is all I was doing with the transformer I would be fine.   Does anyone have any idea which one of the terminals is common?

Thanks,

Paul

All "O" gauge transformers are wired the same with some exceptions, the solution , take a more modern transformer with a breaker switch where the common is marked, then daisy-chain your transformers together. You connect  the track terminals on each of the transformers together. For example if you were to use a a Lionel CW-80 - A-REDTRK and U-BLACKTRK which is common, attach to the MARX track terminals then slowly move each of the control-levers to power up the transformers. If the circuit breaker blows on the Lionel CW-80 reverse your wires going to your Marx if it does not then you guessed right, this is called phasing your transformers, I hope this helps. Just a word of caution, if going to be using an old Marx transformer on your layout do not use with/on any modern locomotives because you could blow the digital boards within. Old engines run with modern transformers okay. I hooked up a TPC 400 via a CAB-1 the other day never seen Marx locos run better. Jim

Skeen Street Junction posted:

if you were to use a a Lionel CW-80 - A-REDTRK and U-BLACKTRK which is common,

 Be very careful, until ~2006, the red posts on the CW-80 were common.

Here is Marty's excellent illustrated transformer phasing tutorial.

ADCX Rob posted:

Here is Marty's excellent illustrated transformer phasing tutorial.

ADCX Rob posted:

Skeen Street Junction posted:

if you were to use a a Lionel CW-80 - A-REDTRK and U-BLACKTRK which is common,

 Be very careful, until ~2006, the red posts on the CW-80 were common.

Black, red and or silver nuts either way the common terminal with Lionel is clearly marked with/by a "U" and has been that way as far back as 1956 as I can recall, the most important feature  here to remember is to use a that modern transformer where the common terminal is clearly identified and the transformer comes with circuit breaker  be used when phasing testing being done, if you do not something they will start smoking or you'll blow your circuit breaker in your panel.

"...the common terminal with Lionel is clearly marked with/by a "U" and has been that way as far back as 1956,,,"

With a couple of exceptions.

Thanks all for your help.  I actually have a LW transformer and A is the common on that transformer. 

Before 2006, the "U" posts on the CW were not common.

The "A" post is common on 1033, 1032, LW, TW, and all other single train transformers.

ADCX Rob posted:

Here is Marty's excellent illustrated transformer phasing tutorial.

It is excellent.  Thanks Marty for taking the time and thanks Rob for posting the link.

TRRR

 

OhB1 posted:

Thanks all for your help.  I actually have a LW transformer and A is the common on that transformer. 

Paul, after seeing your LW with the A-COMMON I got wondering so I gave the ones I had another look over and sure enough there it was "COMMON". Not ever noticing this engraving prior to this I always wired up the outside rails to "U". So I took to wondering and I daisy chained one of my LW's to a CW-80 i.e. U to U and A to A as suspected no problem what's so I then referred to the operating instructions on the LW "MULTI-CONTROL" Transformer and where I discovered Lionel's wiring diagrams showing "U" terminal as going to the middle rail for "O", "O27" and Super "O" and "A" to outside. Best guess the changes must have taken place when everything started getting high tech. You know it is not a good day unless you learn something new, just remember not to operate anything new locomotives on old transformers.

Skeen Street Junction posted:

... Best guess the changes must have taken place when everything started getting high tech...

Well, no.

The convention up until the MW transformer was introduced, with very few exceptions, is the "A" post is common on single train transformers, "U" is common on multi-train transformers(Type R is an exception).

Wow I really thought this was going to be an easy answer! I'm glad everyone learned a little in the process! 

OhB1 posted:

Wow I really thought this was going to be an easy answer! I'm glad everyone learned a little in the process! 

If your think this is interesting and are thinking about getting into Lionel  and/or MTH remote control well I'll tell the fun only just started. When I got back into it I thought I would stick with Post War stuff, I was wrong. Along with a bunch of other old farts we operate a layout at local area model railway train shows, if it works enjoy.  Jim

https://www.youtube.com/channe...OCqlNzFNeJNZEp_P-SlQ