New Lionel ZW-L Old A/F Locomotives

  I think the old Flyers use a frequency change from pure sine for the whistle horn vs the DC offset of others.

 I don't know what the dc AF units did.

There must be a power ripple that the whistle relay system can see as an activation signal. Or it sees a tmcc-Legacy signal as one. A "search" or "availability" signal might be getting picked up?

Here's something funny: My AF 18b transformer blows all my TMCC whistles all day

But it has no whistle control  A conspiracy?  

I wrote about this problem over a year ago in the S Gaugian.  I hooked a Lionel Bridge up with my Legacy system and used a Lionel TMCC Powermaster to power the track.  The Gilbert horns went full time.  I contacted Mike Reagan of Lionel about the situation.  He couldn't give me a good answer.  I asked if it was because the Powermaster converted the power to a chop wave sine from a smooth wave sine.  He said that might be the problem but he still wasn't sure.  My guess is your new Lionel transformer has a chop wave sine and that is causing the problem.  

My TPC 400's make the same thing happen.  I disconnected all the Gilbert Air Chime Whistles and Diesel Horns in so equipped engines (326, 336, etc.).  I think it is due to the use of a chopped sine wave in the new gear as opposed to fully-formed purely analog AC sine wave of the old.  Not such a bad trade off for me as I like to run conventional and command-equipped engines with a Cab2 with all the transformers out of sight and out of the way under the layout.  

All of a sudden, I have a strange urge to paint a tender with white out, and burn paper.

Even though it would likely take a boxcar to hold the paperwork

The Gilbert whistles in the tender were operated by a vibrator that added harmonics to the 60 Hz power sine wave. Any phase control power supply will also produce harmonics that can be heard in the reproducer in the tender. Even MRC's O27 Dual Power causes the whistle to sound constantly. The two easy fixes are to use only a pure sine wave transformer or disconnect the wire to the transducer in the tender.