In the case of production, the 500AT & 550AT were made from the mid-1950's, and discontinued in the early 1980's. As with coverage, they produced 120-125 dB, and covered around 1/2 to 3/4 miles. Finally, the port ratios were 8 & 12 for single tone, and 8/12, 9/12, & 10/12. I never knew ...

ver tum wrote: I've never heard of any other city that did that.

Wichita Falls, Texas also does that. They added Whelens (with a recorded Thunderbolt sound), and they took down all the 2t22s and SD10s and replaced them with Whelens or old Thunderbolts. As far as I know, they still maintain the Thunderbolts.

Hey, did you happen to drive thru Stamford? They got some new electronics, Whelens, I believe. I haven't been there since they got them. I was hoping to get their old Thunderbolt.

I see that Fort Worth finally took these 2 down:



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Yes, I have a recording of one from a siren contest a few years ago.

Yup, the P50 was still there as of about 3 months ago. All of their other sirens are 2001s. Euless also has two P50s in service. If you can settle for a T-135 instead of a P50, there is a T-135 in Sanger Grand Prairie and Bedford Texas also have T135s in their systems. -b- Does Euless still have th...