ZW whistle diode replacement, blow modern whistle/horns better?

It should. Some engines demand a diode.

I have a couple of PW tenders that dont like diodes though. It can be a catch 22. 

So I use 8a diodes in a homemade whistle button box (1033s, you need bigger) There are threads on it. I'd add a bell option too since most new stuff has that ability.

I already have 6-5906 sound buttons for the bell. I'm hoping the stud diodes will cure the having to push the lever half way to trigger the whistle/horn in my RailSounds 5.0 and PS2 locomotives. 

   A dpdt toggle should be able to  turn the bell control to a whistle/bell control by reversing the connections. 

  That button if inline is kinda a weak link. I think they only have a 6 or 8 amp capability. The ZW can cook that with the right short. A 5.5a-5.75 amp fuse for each should save the button. (or 7.5amp-ish if they handle 8a; 9.5 for 10a,etc. )

With 2 buttons per track you can also tie red from#1 and black from #2 together. Then the two remaining leads go to track and power, just like you have now. The which goes where does not matter. If you swap the wires, the function of each buttons swaps  whistle becomes bell. bell becomes whistle.

The newer replacement diode discs work much better than the original copper oxide discs.

Adriatic posted:

   A dpdt toggle should be able to  turn the bell control to a whistle/bell control by reversing the connections. 

  That button if inline is kinda a weak link. I think they only have a 6 or 8 amp capability. The ZW can cook that with the right short. A 5.5a-5.75 amp fuse for each should save the button. (or 7.5amp-ish if they handle 8a; 9.5 for 10a,etc. )

I've upgraded the wiring in the 6-5906 buttons. They work fine for the bell. I just want the whistle button to work without slowing the trains, and I'm hoping the stud diodes will do that. 

Likely it will.  I'm just saying there are exceptions. 

 Electronics is not always as cut and dry as some folks expect it to be.     Too many options and variables. The variety of models out there alone just throws too many variables for a fast & 100% solid answer.  You might want to narrow things some by listing a diode choice you had in mind. There have been mutiple posts on what this person or the other used, but not a lot of hard comparative testing results.

    A diode get's noticed by a board better than a disc because there is a difference, especially over time, in the shape of the offset wave produced. (i.e. different ramping/chopped shapes).  But the diodes voltsges aren't as ideally suited to all PW relays holding/tripping voltage or a W-motors start up neads.

  The nature of most diodes used in this situation usually have volt  drop. But that is not a given. Diodes types can be/do many things, even voltage boost, emit light, etc. The homemade version shows a trick for getting by with clever stacking of general purpose diodes.(your sound buttons are likely the same design.....except you mentioned a mod, but again, no specifics.

Each bit of info skipped by you in tech chases will make answering harder, more long winded, or very short but very vague) 

I was planning on using an 1N1190AR diode to replace the original rectifier discs. I'm not concerned about operating Postwar whistles/horns as my two Postwar locomotives have been upgraded with Railsounds 2.5 and 3.0 boards respectively. I'm more concerned about triggering modern whistles/horns without a voltage drop, caused by pushing the whistle lever half way to trigger the whistle/horn and not engaging the booster circuit on the whistle control. 

I've modified the 6-5906 buttons by replacing the thin factory wires with 14 gauge wire. I soldered the new, larger wires, in place of the old smaller wires. This eliminated any voltage drop through the button.