Federal 550-AT Naming Convention

[jacob585]

...while the second run was in the mid-1960s with improved sound projectors.

So the on in Callahan, CO is the 1st Gen, isn't it?

Any pictures of the second manufacturing run aka the 2nd Gen?

Sorry for bumping.

There might not be any 2 gens left. I heard only around 50 were made.

[Tyler]

I wasn’t even aware that there was a “2nd gen.”

[LukeH]

Would the second gen use the later 500 projector cone? I wonder if there's any literature we've missed over the years. That would man for an interesting looking siren.

[Darley Champion]

I'm aware of the hacylon 500s (because IIRC the projectors had a factory defect or something else that caused them to flop like jelly) but a 2nd Gen 500 siren...

Never heard of that, if there are any 2nd Gen 500s left in the wild, they must be rare to inexistant.

[Jared H]

The second generation 500s are the 10/12 models, like the one in Byron GA, which went by 500SHTT, and the single tone 500SHST, a la Roscoe MN. You are correct in saying very few are left. Most of the 500s out there are either LA-style or “third generation”, 9/12 500ATs

[Tyler]

I'm curious about this "second gen" 500DHTT/550 I saw earlier in the topic.

[FahmiRBLX]

The second generation 500s are the 10/12 models, like the one in Byron GA, which went by 500SHTT, and the single tone 500SHST, a la Roscoe MN. You are correct in saying very few are left. Most of the 500s out there are either LA-style or “third generation”, 9/12 500ATs

1st Gen 500s are the one with roughly 45-Degree gradient horn with supports and 8/12 Port, am I right? 3rd Gens have LAish 9/12.

And don't forget Dundee Twp's. The healthiest, albeit rotates fast, I've ever seen.

[nvanw27]

And don't forget Dundee Twp's. The healthiest, albeit rotates fast, I've ever seen.

Dundee's has been removed. It now (according to Harman) in a garden.

[Tyler]

And don't forget Dundee Twp's. The healthiest, albeit rotates fast, I've ever seen.

Dundee's has been removed. It now (according to Harman) in a garden.

Dundee's is still up, but it's at another location and is now a lawn decoration.

[uncommonsense]

Are we even sure this supposed second generation 550 is real?