Seek schematic of Federal Signal Unitrol 480K

[Trebor Cadeau]

If not too difficult, I'd like to create a small hand-held box on the end of a cable so passenger seat occupant can hold the box and switch the 480K to different sounds as though turning the 480k head's rotary switch. MANUAL - WAIL - YELP - HILO

Or is that 3(?)-level rotary switch custom made for Unitrol and will be too difficult for me to create?

If I can see the schematic, I can discern what is possible and how difficult.

Right now we have a handheld pushbutton which acts as a foot switch.

In WAIL, if the button is touched, YELP sounds for 5 seconds beforeturning to WAIL.
Can I disable the timer so YELP immediately returns to WAIL when button released?

Thank you.

 

[MtnMan]

It's definitely possible. I don't have access to the diagrams right now, but I can give you some pointers in a few days.

 

[Trebor Cadeau]

Thank you. If it's not too much trouble.
The MANUAL button is nice and good enough.

 

[MtnMan]

OK, I don't have a schematic for the 480K controller, but the 80K amp is activated by +12v inputs for each of the tones. So, it would be simple to wire remote switches to the control cable as shown below. The activated tone that is the higher priority will override the other.

The switches could be pushbuttons or a rotary switch. I added isolation diodes in series with the 480 outputs, which may not be necessary, but they won't hurt.

If you want, take +12v for the remote switches from one of the switched outputs of the 480K. That way, shutting down the 480K will disable the remotes.

 

[Trebor Cadeau]

Wow! Thank you, Mounting Man. (Just being mean.)
Your diodes is a good idea! Better safe than sorry.
This will be easier than expected.