OM-120 Questions

[4J25]

I just have a few questions about the OM-120.

1. How many RPM's is the motor

2. Does anyone have any close-up pictures of the siren

and

3. Does anyone have a cutsheet or any diagrams of the siren?

Thanks!

[CycloneFan125]

I can't answer #3 but I live near the six OM-120's in Brookfield (Hartford about an hour away from me has one too) and they have the same motors as the RM-130 and they're 9 port.

This isn't my video but here's an HD video of one of those:
https://youtube.com/watch?v=K7yXiqgETH0

[4J25]

What motors do the RM-130's have?

[CycloneFan125]

RM-130's have 20 HP motors. Although I've heard two RM-130's (both in Menomonee Falls, WI) and one of them was higher pitched than the other so maybe there's a 25 HP option if that other one was higher pitched?

[DJ2226]

The OM-120 and RM-130 guts are basically a 9 port Screamer S-7.5 on steroids. Before ASC came along the Perf. Plus Penetrator used a 3 phase 240V 7.5 HP motor connected to an inverter which was connected to a rather large bank of batteries. Because the inverter solution was an absolute mess and broke down so much from the complexity of it all, ACA fitted the apprentice with a, presumably, 7 HP DC motor with a much more tamed 72V setup and dubbed it the PN20. ACA did boast about having an omni version of these sirens in an exert from a news paper; I'd have to dig that post up from the board. ASC later went on to call the rotating one the RM-130 and produced the omni variant the OM-120, respectively producing 130 and 120 dB.

In terms of motor speed these sirens usually sound like a 10 port siren, but some of that depends on the voltage going to the motor, condition of the motor, etc. Generally they are in the 585 Hz range +/- a few Hz. With a bit of algebra:

Hz = (Port # * RPM)/60
RPM = (60 * Hz)/Port #

(60 * 585 Hz)/9 = 3900 RPM

There aren't any cutsheets of these sirens online as far as I know, and that's not too surprising given that fact that it's been a good few years since they were last made ex. the 1990's. Given the nature of the sirens though I think it would be a safe assumption to say that they would perform about the same as a T-128 and T-121, maybe a little less. It's chopper is probably about the same size as the one in the T-128, around 14 inches.

There are pictures of them out there and a video of an RM-130 taken apart from I think Eden Prairie, MN. Credits to the original creators of the video and one who took the picture.
ASC OM-120 by freebrickproductions, on Flickr



https://www.youtube.com/watch?v=MWan6L18psQ

[Hacksaw]

There's a bunch of OM-120's under Contra Costa County here:

http://www.jmarcoz.com/sirens/sirenarch ... california

[SuperBanshee]

The OM-120 began as the Performance Plus Banshee, a 115 decibel omni-directional equivalent to the 125 decibel Performance Plus Penetrator. Both were 9 port sirens, introduced in 1989. The base design was improved to put out 120 decibels instead of just 115. Under ASC, it became the OM-120 and continued production until the new Tempest T-121 was established in 1999.

I'll be starting another thread regarding the Performance Plus sirens. It will help to clear up much information regarding these obscure sirens - the reason these sirens are so difficult to understand is because they were only made for a few years (1989-1993) and during that time they changed multiple times.

[CycloneFan125]

It's like how the OM-117 is pretty much the ASC branded Banshee and the OM-120 was the upgraded version of that and how the RM-127 is the ASC branded P-10/15 and the RM-130 is the upgraded version of the RM-127.

As for locations of OM-120's in the US this is what I know:

6 OM-120's in Brookfield WI
1 OM-120 in Hartford WI
3 OM-120's in Boaz AL
18 (or more) OM-120's in Contra Cosa CA

RM-130 locations include:

10 in Menomonee Falls WI
9 in Fond du Lac WI
4 in Oconomowoc WI (not in service anymore)
1 in Joliet IL (might be a PN-20)
1 in Elk Grove IL
4 in Hoffman Estates IL
2 in Schaumburg IL
1 in Rosele IL
1 (maybe more) in Decatur IL
some as mentioned in Eden Prairie MN

[Stevan Z]

It's like how the OM-117 is pretty much the ASC branded Banshee and the OM-120 was the upgraded version of that and how the RM-127 is the ASC branded P-10/15 and the RM-130 is the upgraded version of the RM-127.

As for locations of OM-120's in the US this is what I know:

6 OM-120's in Brookfield WI
1 OM-120 in Hartford WI
3 OM-120's in Boaz AL
18 (or more) OM-120's in Contra Cosa CA

RM-130 locations include:

10 in Menomonee Falls WI
9 in Fond du Lac WI
4 in Oconomowoc WI (not in service anymore)
1 in Joliet IL (might be a PN-20)
1 in Elk Grove IL
4 in Hoffman Estates IL
2 in Schaumburg IL
1 in Rosele IL
1 (maybe more) in Decatur IL
some as mentioned in Eden Prairie MN

There's actually two in Elk Grove Village, IL.

[Valra Bellkeys]

It's like how the OM-117 is pretty much the ASC branded Banshee and the OM-120 was the upgraded version of that and how the RM-127 is the ASC branded P-10/15 and the RM-130 is the upgraded version of the RM-127.

As for locations of OM-120's in the US this is what I know:

6 OM-120's in Brookfield WI
1 OM-120 in Hartford WI
3 OM-120's in Boaz AL
18 (or more) OM-120's in Contra Cosa CA

RM-130 locations include:

10 in Menomonee Falls WI
9 in Fond du Lac WI
4 in Oconomowoc WI (not in service anymore)
1 in Joliet IL (might be a PN-20)
1 in Elk Grove IL
4 in Hoffman Estates IL
2 in Schaumburg IL
1 in Rosele IL
1 (maybe more) in Decatur IL
some as mentioned in Eden Prairie MN

No love for the 6 RM-130's in Chickasha, OK?