Tell me if this seems right or if I’m missing something. I tried to put them in order by year.
Simplex 4030
Simplex 4037
Simplex 4040
Simplex 4041
Simplex 4048
Simplex 4050
Simplex 4051
Simplex 9833
Simplex 9806
Simplex 9838
Simplex 9219
Simplex 9422
Simplex 9252
Simplex TrueAlert
Looks about right. I think the 9806 came before the 9833 though. There was always overlap between the Faraday and Federal Signal notification appliances, so they would’ve been in Simplex’s product line at roughly the same time.
What was the purpose of having similar horns (the -9806 and the -9833) from two different companies anyway?
I put the 9806 after the 9833 because I saw 9806s on 4904 plates as well as 9838s on 4904 plates (online of course) so I thought they would be closer than the 9806 and the 9833.
I think I remember seeing that Simplex sold the 2901-9806 from the late 70’s up to the mid-90’s when they stopped using Federal Signal products. Meanwhile, the 2901-9833 was discontinued and replaced by the 9838 around 1985 or so.