I was looking around on the CADL photo archive, when some photos caught my attention. I was looking around for civil defense pictures when I found these two photos: 1. (description from archive) "Men looking at heavy equipment, at either the north or south side entrance to the Michigan capitol ...

It unfortunately might not be possible to tell them to not take it down. It still very may be likely, just be careful about who you ask about it, and be prepared for your plan to backfire. They might have some good reasons why they want to take it down! I'm fine if they want to replace a very old T...

The CD logo was typically a decal that they would put on the siren. They usually used a highly adhesive sticker or glued the decal onto the siren itself. If you need it, here's an original CD logo you can use: https://upload.wikimedia.org/wikipedia/commons/8/88/Roundel_of_the_United_States_%281961%E...

I for some reason can't see the images. You may have to upload the images to the post, so they are more likely to be seen!

It unfortunately might not be possible to tell them to not take it down. It still very may be likely, just be careful about who you ask about it, and be prepared for your plan to backfire. They might have some good reasons why they want to take it down!

Unit of Civil Defense wrote: ↑

Sun Apr 07, 2024 5:48 pm

....I thought your question got answered here....perhaps I'm wrong
viewtopic.php?t=29744

I guess I didn't see the 1000T part of the oldest Thunderbolt yet. I also guess I could've forgot I looked at it too!

Where are the first sirens in a siren series located? If the actual first siren was removed, it can be the oldest still around. It can also be the different models as well as the oldest siren in that series in general. I just came up with this idea while I was looking around siren maps, and I finall...

Lastly, I heard about some sort of horn that uses a chopper-stator mechanism like a siren, but uses some sort of mechanical damper to blast the horn open and closed. I have a video from VintageCollection showing this and I wanted to know what these are called. https://www.youtube.com/shorts/Ch6_3h9...

Here's a really old image of the San Francisco Ferry building Heath siren in 1945. An electrician was working on it at that time. Holy cow! I didn't even know that another photo of the siren still in good shape existed, let alone a close up! Where did you find this photo? The only photo of this Hea...

and what about resonating horns? Sorry for a late reply, but resonating horns work almost the same way as a diaphragm horn. Instead of air, it uses an electromagnet to vibrate a metal plate that moves fast enough to create sound, basically like a simple speaker. The electromagnet is hooked up to a ...