Skip to main content

The new MTH Z-4000 and Lionel's modern ZW are way out of my price range.  That leaves whatever is left of the newer type transformers.  So is there any advantage to using one of the newer type transformers when running conventional, mostly post-war locos ?

If there is an advantage to the newer technology, which ones would be good for powering the track, figuring locomotives like post-war F3s, Trainmasters and GG1s as the predominant motive power ?

Original Post

Replies sorted oldest to newest

The MTH Z-1000 may be in your range. They are about $100 new, less used. 100 watts, good quality. Truly excellent little transformers and the absolute best in that prices/size range. Should have no problem running modest Postwar trains. Been there, done that on my own layout! 

I love Postwar and Modern trains and run them all - Postwar, Modern Conventional, MTH PS2/3 and Legacy. I would, in no way, use a Postwar power source. I don't care how rebuilt it is, I just don't trust it. Modern gives you piece of mind and, most importantly, new circuit breakers and related protection. If you try running modern trains with a Postwar ZW without additional protection, you'll be cooking engines if there is a derailment. 

I used MTH Z-1000s for years. I have one in storage as a "back-up". About a year ago, I replaced my 10+ year old Z-1000s with three brand new, state-of-the-art Z-4000s. Didn't need that much power but it is good to have, not to mention a warranty and the newer technology. 

I've seen plenty of layouts running Postwar power sources. All of them are hot enough to cook on after a few minutes. You'll never get a modern transformer that hot, at least I've never seen it after 25 years in the hobby including 11 years of modular club railroading (where you sure as hell see the "extremes"). 

Last edited by SJC

Great answer by "SJC" above.

I use an MTH 4000. I paid about $400 for it a year or two after they first came out (maybe around year 2000). I saw a used one in a White Plains, NY train store about one month ago for substantially less (my recollection is that it was about $150 to $200). Might be a good deal if you can get a good technician to examine it to make sure it is in good condition.

It's nice to buy new and get the warranty.

In addition to the MTH 4000 to run my 2 separately blocked main lines, I also use 2 postwar ZWs to run sidings, switches, and accessories. They are quite economical used and in good condition (maybe $100 to $150). For the serious and knowledgeable adult hobbyist, I think the post war ZWs are fine. One drawback is they don't have the bell function, I agree they do warm up after 10 or 15 minutes running trains. They are work horses with good power, easily fixed by qualified technicians and there are plenty of available parts.

Last edited by Arnold D. Cribari

Have small 4x8 layout no switches with 2 postwar zw's run dcs and or conv on outer and inner loop with some lights and a few old bubbling towers and a older rotating searchlight .One zw powers one track while the other powers other track both have inline fuses. To switch back and forth for dcs or conv on either track i use banana jacks .

Run trains for 1-2 hours at a time prewar and postwar lionel fm's f3s gg1 etc, marx, williams and mth ps2 engines and 1 ps3  engine .

Never upgraded the tiu bought as set with remote in 2002 along with a spare remote still not used.

The transformers get slightly warm but never hot replaced rollers myself in them perhaps 10 years back.

Cannot compare to modern ones as i do not have any mind you layout only 4x8.


Last edited by Dieseler

if a ZW is pushed near its limit, then yes it will get hot.  Running a dual motor 2333 and a single motor turbine, barely gets warm on the case after 1 hour running non stop.  Now granted I am not pulling a sting of lighted passenger cars right now either.   A ZW in good condition with good or newly replaced rollers on the big handles is hard to beat price wise right now.   Watch facebook market place, seen several locally for really good prices.  They are not that hard to work on and rarely need more than a cord.  Yes if you run newer engines that have sound boards, you must be carefull as the circuit breaker isnt fast enough if the engine eats it and shorts out.  That said, I have never in all my years burned up older railsounds board, RS2.5 and older, running on a bone stock ZW with no extra protection and I had plenty of derailments back on that old layout.  Older postwar, no worries.   If you need bell control, Lionel offered a seperate button to wire in to give that option.       Mike the Aspie

The circuit breakers are strictly to protect the transformer itself, and not beyond.  To protect the newer electronics in today’s loco./tender combos, the use of TVS’s (transient surge protectors) is what is required.  This subject has been beat to death on all forums.  Also the use of external circuit breakers beyond the transformer.

My experience has been postwar transformers and new trains don't play together well. Same in reverse. Newer electronic transformers, especially the Lionel CW80, make older AC motors growl and get hot. They work fine with a DC motor and electronic reverse unit. Another problem is they don't like postwar whistle and horn relays. Many times the whistle will not work.

In the opposite, postwar transformer whistle control doesn't like modern electronic whistles and horns, and as already stated, the internal circuit breakers are too slow and meant only to protect the transformer core. TVS's or a Lionel postwar # 91 instantaneous circuit breakers highly recommended.

For my money I would go with a ZW transformer.  They are easy to work on and also will boost the voltage when using the whistle control.  You can't beat them for operating post war equipment.  If you are going to use the occasional newer locomotive I would add separate horn and bell controls as they seem to work better with the newer equipment and you also get the proper DC offset.  Also as previously pointed out TVS's should be added as well.  They are dirt cheap and provide protection for the new electronics.

My 2 cents

The original ZW transformers will last virtually forever with some minor modifications. Replace the original rectifiers with 1N3311B Zener diodes (Disconnect the Nichrome wire resistor), add TVS diodes to the outputs (1.5KE36CA) and fuse the power leads. This will provide both voltage and current overload protection and create a very stable whistle control with far less engine speed variation.

The original ZW does not rely on IC chips nor power transistors found on modern transformers. The modern internal devices often go obsolete or include cheap circuit boards with weak traces which make repairs difficult. The original ZW's were made to last, produce true sine wave output and were made during a time when serviceability was an important consideration.

The problem with ZW and most or all older transformers is NOT necessarily the breaker, the rollers, or the cord.  Many older transformers used what I would call "paper" for insulating the individual segments of the punching stack, and as this "paper" aged and deteriorated with heat the stack gets loose.  That is why many old transformers "humm".  That is 60 Hz 120 volt power vibrating the stack.  A loose stack, in addition to reduced efficiency and the result, running hot, is harbinger of a potential future transformer failure.  I am not aware that any "overhaul sites" for ZW's are restacking the transformer core.  I have had a few ZW's, and they do not even have an Off-On switch.  If you forget, even once, to unplug or disconnect a ZW after operating your trains, you are at risk.

If you value your trains, and possibly your house, get rid of all this old stuff and buy something with a modern, higher rated, and non degradable insulation system and UE protection.

My $0.02

Personally, I think the PW-ZW properly maintained and with added circuit protection can be a very reliable power source.  The lack of a power switch is a non-issue IMO.  My four Lionel Powerhouse 180 transformers do have power switches, but those switches are never used.  I have a master switch that turns off the whole layout, which I highly recommend for any layout, regardless of the vintage of the transformers.  There are any number of sources of greater fire risk than a properly maintained PW-ZW on your layout.

I don't know what UE protection is, but if you're talking about UL, that's no warranty of a solid design that will stand the test of time.

My $0.02

Former Member

For post war trains you might consider the Lionel LW transformer.

Many here consider the LW the best transformer made to run one loop or up to two trains per loop.  Many others have also come to this conclusion and written about its advantages and unique features.

LW transformers input 125 watts for one train or 62.5 watts per train when running two trains per one LW.  By comparison a ZW at total 275 watts or divided by 4 gives 69 watts per each train loop.  LW transformers put more input watts per train than any other Lionel post war transformer.  Also the LW transformers are less expensive than most other transformers, most of mine cost $30 or less each but $50 is better now.  I have been using 3 LWs for over 40 years without issues.  I use 6 am reset-able circuit breakers for each.

LW transformers have a lighted dials which shows when the transformer is putting out any voltage and the light varies in intensity as the voltage to the track is changed.  The light also shows when there is track voltage on even when the external circuit breaker is thrown.  The lighted dial makes night operation better showing the voltage at night.

Just another choice for you to consider.


From St. Louis, MO

Last edited by Choo Choo Charlie

I'm with GRJ.  I have circuit protection on all my PW transformers.  They play just fine with my modern trains.  Been running this way for years without any issues.  No they don't get hot either!   If your transformer is more than warm something is wrong.

If you don't want or are not interested in the necessary circuit protection to run PW power safely then buy modern. 

First off, the postwar transformers are rated on input power, and you have to take that into consideration when you add circuit protection and calculate the load they'll support.  Let's say the efficiency of the PW-ZW is 80%, that's a reasonable assumption.  The ZW rated at 275 watts is really a 220W output transformer, so we're talking 11-12 amps at full throttle.  My recommendation would be to provide suitable circuit protection based on the real capacity of any transformer, the PW-ZW included.

For the ZW, if you are feeding multiple tracks, I'd provide each output with circuit protection suitable to support the load on that output.  I'd also provide unified circuit protection in the common ground lead to avoid multiple outputs totaling more than the transformer should be loaded to.  That way you can provide proper protection for each output and also not be constrained to a fraction of the usable capacity of the transformer.  Each output could have an 8-10 amp fuse or fast circuit breaker, and the common ground connection could have a 12 amp fuse or fast circuit breaker.

Add Reply

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
Link copied to your clipboard.