U.S. PTTF Fuze, Pre-WWII

[bacarnal]

Can't remember where or when I got this Fuze, but I don't know what the nomenclature is. By the design I would think a PTTF (emission holes under the WS) for AA use and U.S. because of the pitch of the threads 1.7"x14 tpi NF. There are no numbers on the timing ring, but the adjustment slots also look U.S..
Any help would be appreciated.

 

[Alpini]

Hello,

have a look at the attached pictures. It' a Junghans design. But I wonder if it is unfinished or another experimental example because there are some differences to the drawing.

 

[sgdbdr]

It could also be a M43 wich superseeded the M2 and is of similar design except for the thread and the booster, according to TM 4-205 (1942)

 

[bacarnal]

Thanks, all. It was also identified as the M2 fuze for the M38 105mm AA (M3 AA Gun) on the IAA Forum. From the publication you posted, Alpini, it looks like the threads are of the older WWI Rounds, such as the M1907M PTTF Fuze. As described in TM9-1901 1944, the M2 fuze was adapted to take the new booster adapters (like the M20/M21 Series). As far as the M43, the documents I've seen over there show the original M43 to look like this except that the aluminum wind screen was cut down and the profile was more like the later all aluminum M43A Series. Thanks again!!