Zw question

18 volt #1445 bulbs are in my ZW

Larry

Most ZW transformers use an 6 volt bulb, #51

Model "R" ZW transfomers use an 18 volt bulb #1445.

How do you know if you have a Model "R" ZW and what is the difference with a Model "R"?

I believe they are stamped on the bottom.

If you open the case, model "R" does not have any resistors in series with the pilot bulbs.

I think that an 18 volt bulb in the green pilot socket would be dim on a non-R, and normal brilliance on an "R".

There is also a wirewound resistor mounted right on the whistle control board on the model "R".

The differences are documented in the Lionel service manual, including every reprint that I have seen. Perhaps Olsens will have the ZW pages back on line soon.

Another distinctive look in the ZW-R is the transformer laminations will have no gaps, the plain ZW there are gaps evident on the transformer core.

Thanks

gunrunnerjohn,

   Please explain the ZW-R, as far as I know there are two different ZW's

a Pre War 250 and a Post War 275.  I own and use both on my layouts.  Along with 2 KW's  and a Z4K.  Which is the R or are there two different Post War 275 transformers?

PCRR/Dave

Pre War 250

275 Post War

Re gunrunnerjohn's comment -- Not all ZWs with riveted laminations are Model Rs. It doesn't seem to be clear exactly when they began riveting the laminations, but it was years before the Model R appeared (indicated by the 18V 1445 pilot lights) in 1961. I have one with the riveted laminations that I received for Christmas 1958.

Martin

There were actually more than 2... the ZW was made only starting in 1948(none prewar).  There were ongoing changes & improvements internally over the years while remaining essentially unchanged externally.

A major change had to do with the switch to a two piece lamination for easier assembly and quieter operation, which came many years after the input rating change from 250 watts to 275 watts and before the designation of the "R" model.

While the catalogs never made any mention of internal changes, the one thing that was very clear in the service documentation was that starting with those models that eliminated the indicator lamp resistor wires and the switch to 18 volt bulbs were to be considered "R" models. 

The "R" models may or may not be marked or stamped as such, but by at least 1961, with this last revision of the ZW's innards, the "R" model had incorporated all production updates and was the same from that point on.

What he said.  

All of the ones with the riveted lamination I've seen have been stamped ZW-R, I didn't realize they started before the "official" designation.  In any case, my testing shows that the R models had a little more power capability with less voltage droop with the same load as the older plain ZW models, supposedly due to better efficiency of the core.

[Mainly repeating much of what ACDX Rob said, with a bit of elaboration here and there.]

First, there were no prewar ZWs; the first year was 1948. There were Zs made before the war (no whistle controls, thus no "W"). 

There were, broadly, the following variations of the ZW: (1) 250W, 1948-49; only an "L" escutcheon on the (small) top plate, electrical info on a separate plate on the back of the case; (2) a few 275W with the electrical info plate on the back and small escutcheon on the top, tail end of 1949 production and/or very early 1950; (3) 275W with a larger plate on the top which included the electrical information, no back plate, 1950-???; riveted laminations introduced, date unclear, ???-1961; (4) Model R, defined by the 18V 1445 pilot and overload lamps (as oppsed to the 6V #51s used in all previous versions), 1961-end.

Some/many/most/all Model Rs were identified by a stampd label on the underside of the base plate, though a few had heat stamping on the back under the binding posts in the same style and typeface as the "COMMON" and "UUUU-ABCD" heat stamping. It's entirely possible that some had no ID at all.

Martin

Gentlemen,

   Thanks for the education.

Martin I know my one ZW is a very early model, because I do not remember much before 1949 and the ZW was always part of my train set, I always thought it was a Pre War transformer, if it was made in 1948 that would explain why I believed it was Pre-War I was just to young to remember my Grandfather purchasing it.

I do remember my Father selling the original Z in 1950.

I really appreciate the knowledge, I often wondered how old my original 250 ZW really was.  That makes her 65 years old this year, and still operating perfectly,

made in America with a life time guarantee, ya got to love the original Lionel trains.

PCRR/Dave