Since I have mentioned this a few times, I might as well make a topic explaining.
What is the last Thunderbolt model? Well, the C-series of course. No that's actually incorrect. Yes that was the last mass-production model, but wasn't the last model at all. The last model is probably the least known model of the Thunderbolt and there is a reason too. This model wasn't really popular and it never was advertised that well. They sold only 10 units, and these units are now gone as far as we know. It is possible that someone can come across one, and they aren't hard to miss if you see one.
So what is this mysterious Thunderbolt I'm talking about? Well it's a white single-tone unit with the belt-less rotator we see on the 2001-SRNB, small RCM cabinet and smaller blower unit.
It looked like this:
WHOA WHoa whoa, hold on, the Thunderbolt never had this rotator. That rotator came out in 2003. Actually yes it did, and it was the first siren to have it. It was a Thunderbolt exclusive too. After mass-production ended for the Thunderbolt in 1990, Federal was selling 2001s, and Thunderbolts too until they would eventually run out of stock. In 1993, they wanted to attempt a modernization project on the Thunderbolt, because it was such a popular siren, and played a big part in getting them to where they are now. They knew it would sell just from its reputation alone. They started looking into the most problematic parts in these units and narrowed it down to the rotator in particular. As we all know, the old units had a motor, a gear reducer, and a belt to drive it. Although the system worked, it wasn't really maintenance free and was prone to breaking, as in the gear reducer running out of oil and stripping out, or belts snapping. They wanted to be rid of these issues and came up with a new unit that used the same core, but used a new low power, slow turning motor. The motor was turned upright and drove the spur gear directly. It was super efficient and effective, so they made a few units and added this to the new project. Next they worked on the RCM, making it more compact and easier to work with, did the same with the blower, and added in a more reliable radio into it. Thus came a new Thunderbolt unit with a bunch of improvements. Federal put it on the market and sold it beside the 2001. Sadly it didn't quite meet their expectations, which was probably from poor advertising, and booming popularity of the 2001. They managed to sell 10 units, but then pulled the plug on it. Now they were left with a few belt-less rotators and a lot of old units from 2001 mass production and a little bit of leftover Thunderbolts. Federal used up the massive stock of rotators and finally integrated the new rotator in 2003 with the 2001-SRNB.
Special thanks to former Federal member Jeff Morrison, and knowledgeable member Jonathan Callahan for helping provide the information on this awesome siren.