# Rocket B unit horn



## hcopter51 (Aug 29, 2018)

This might be dumb but what type of horn was installed? Air chime or diesel? Thanks, John


----------



## Sagas (Dec 13, 2013)

It is described in the 1953 catalogue as Air Chime. It works with a control box into which a metal cylinder is inserted (like an old TV tube). When the button on the controller is pushed it causes a vibrator in the tube to send a signal to the speaker in the PA2 unit.

Honestly, they don't sound like a real whistle and I don't use them myself but if you have the controller and tube you can wire it up and give it a try. If you don't get any sound it may be that the vibrator in the tube is dirty or stuck together in which case you can pry open the tube at the base (its not vacuum tube), clean the contacts, close up and try again.

J.B.


----------



## hcopter51 (Aug 29, 2018)

Sagas said:


> It is described in the 1953 catalogue as Air Chime. It works with a control box into which a metal cylinder is inserted (like an old TV tube). When the button on the controller is pushed it causes a vibrator in the tube to send a signal to the speaker in the PA2 unit.
> 
> Honestly, they don't sound like a real whistle and I don't use them myself but if you have the controller and tube you can wire it up and give it a try. If you don't get any sound it may be that the vibrator in the tube is dirty or stuck together in which case you can pry open the tube at the base (its not vacuum tube), clean the contacts, close up and try again.
> 
> J.B.


Thanks JB, Mine sounds like a loud humming sound that increases when I press the control button....Have the speaker in my Rocket PA unit so I thought I would try it....Maybe the problem is in the PA unit itself.....Wheels are clean and do not spark at all which is sometimes a problem....Just thought I would try it and see what it sounded like....I usually just use the billboard horn sounds anyway....Thanks again, John


----------



## AmFlyer (Mar 16, 2012)

A couple of things to check. I assume you have all the track power connections wired through the controller. You must use a pure sine wave transformer such as a postwar Gilbert or Lionel. If any of the more modern transformers are used the horn/whistle will sound continuously. This is because the modern transformers have switching harmonics in the output waveform that are reproduced by the speaker. The truck sideframes should have sliding shoes for electrical pickup, not relying on the wheels. The wheels also pick up power. All diesels and steamers with air chime had the sliding pickups.


----------



## hcopter51 (Aug 29, 2018)

AmFlyer said:


> A couple of things to check. I assume you have all the track power connections wired through the controller. You must use a pure sine wave transformer such as a postwar Gilbert or Lionel. If any of the more modern transformers are used the horn/whistle will sound continuously. This is because the modern transformers have switching harmonics in the output waveform that are reproduced by the speaker. The truck sideframes should have sliding shoes for electrical pickup, not relying on the wheels. The wheels also pick up power. All diesels and steamers with air chime had the sliding pickups.


Thanks Tom, Yes, I am wired through the controller and am using an 18 B transformer....As far as sliding pickups I have not noticed if they are there or not...Never really looked, but I will now....Thanks again, John


----------



## AmFlyer (Mar 16, 2012)

Most likely then is the condenser used to block the 60Hz power frequency has failed. Its a capacitor, we used to call them condensers. When the capacitor fails a constant hum will be heard from the speaker. Replacements are available from AF vendors if you only need one.


----------



## hcopter51 (Aug 29, 2018)

AmFlyer said:


> Most likely then is the condenser used to block the 60Hz power frequency has failed. Its a capacitor, we used to call them condensers. When the capacitor fails a constant hum will be heard from the speaker. Replacements are available from AF vendors if you only need one.


Hi, I checked and my PA has the sliding pickups all right....I do not hear anything from the speaker when power applied to the rails until I press the control button...The sound increases when I add more power and just sounds like a loud hum....Hard to describe the sound but I am wondering if that's what I am supposed to hear....Oh well, guess I'll have to take it to someone who knows what it is supposed to sound like....Does NOT sound like it does on U-Tube tho…..John


----------



## AmFlyer (Mar 16, 2012)

They make more of a buzzing than a hum sound when working correctly. I disconnect the speakers on any I want to run so I can use them with my ZW-L's.


----------

