The beacons are Federal 184 Power Lights on top of the cab. They are big beacons, but there are some others that I know of that are slightly bigger that are still in production, and others that are not anymore.
Signal Stat 370 and 374 beacons (photo NYPD bar 374s courtesy of Pdfootman)
Yankee 354 (photo credited to CFD125)
Whelen 994 beacons, both regular base and speaker-base versions (Photo credits to Dale Cohen and Motorolamaniac)
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Sireno 44460-0442 and 44460 beacons (photo of red one credited to Diggerdoug again)
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Peterson 759
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North American Signal 400-X and their rare par46 version of the 400-X (photo of second light credited to John Marcson)
Dietz 211 and 7-11, both standard and "hill light" versions (photo of 1st Dietz credited to ccomm911, second to John Dorgan)
Unity RV-26 and 46 (par46) and RV-45 (par36) beacons. Photo credits to Dale Cohen and Alundborg
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Federal 184H "High Boy" and CJ184. Photo credit to Oshkosh619. I know he's a member here, I just can't remember his username at the moment
Dietz 7-11 on a VSP 8-211 speaker base, which are very rare to come by according to Diggerdoug. He had this one restored and up for sale on his website
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All of these are the same dome and base design, but the rotator assemblies vary with
par bulb size and the bulb-plate holders. These are the largest diameter and height for any beacon to be used on a vehicle, minus the 120V Mark 12.
Tri-Lite/Tripp-Lite RF-64 and S-74(photo credit John Marcson for these Tripp-Lites), Tri-Lite Mark 12 (I own two of these: see avatar), and the rare Tripp-Lite S-75, which was their version of a Federal 175 beacon
Okay......that's it as far as I know. Others can fill in the ones I'm blanking out on. I'm going to bed now......
:sleepy: