Can Fed. Sig. PA 300 be modified to do wail/yelp together

[Unit of Civil Defense]

I am doing a resto-mod on an antique police car ...I have a Federal Signal Corp. model PA 300 siren control and am wondering if the wail and yelp could be combined to get this sound...watch the clip http://youtu.be/svrDahAm48w there is someone else with one of these PA 300's who is wanting to do the mod to the unit if possible for his "unit" ....so "we" would appreciate any help or advice on this...THANKS!

[landmobile]

Thanks for posting the link, it really took me back in time

Most electronic sirens of that vintage used a pair of analog oscillators, one to generate the siren tone and a second to modulate the frequency. Changing the selector from wail to yelp switched in different resistors and/or capacitors that changed the RC time constant of the modulating oscillator. Since there is typically only one siren tone oscillator, I don't think it is posisble to mod a PA300 to generate wail and yelp simultaneously. The sound from the TV show was most likely a Holywood fake, just like the Federal fireball light on the roof.

[Unit of Civil Defense]

.......One guess and the first 2 don't count on what my antique cop car is/will be (work in progress) and the other guys unit is....yea, the siren and exhaust sounds where "canned" there was a siren from the mid 70's to early 80's ? that had the wail/yelp together...I think it may have been a Southern VP? don't remember... it's been a while.

If you "dig"the car , here is where we "hang out" http://forum.grantorinosport.org/starsk ... rum35.html 8)

[landmobile]

... there was a siren from the mid 70's to early 80's ? that had the wail/yelp together...I think it may have been a Southern VP? don't remember... it's been a while.

You're right, there are some that do a dual wail/yelp. I have heard them in ambulances around here, but I don't know the manufacturer.

US Patent 4075624A http://www.google.com/patents/US4075624 for a dual wail/yelp electronic siren was granted in 1978 and is referenced by several manufacturers, including Whelen and Federal.

I can only geuss that you're restoring a Gran Torino. That's a great project; much more unique than the typical Caprice or Crown Vic. Best of luck!

[JasonC]

You can modify it to do phaser, but you cannot do more than one tone at a time.

[Unit of Civil Defense]

....What are the chances of being able to commission someone to build a couple of simple wail/yelp ONLY dual tone sirens.....12v DC driving 2 100w speakers for the dual tone sound.

Here is a link to what we (there are two of us looking for this sound) are after....
http://www.carson-mfg.com/sounds/wail_and_yelp.mp3

Here is a link to the "canned" sound effect siren from the T.V show ...we have the cars....just need the siren to complete the project.
https://www.youtube.com/watch?v=svrDahA ... e=youtu.be