1198th Operation, Evaluation and Training Squadron

[Bearmon]

I posted this one in the "Can you ID" section it was identified and I thought it should be posted here also.  A very interesting history for a VN era Insignia 

From Wikipedia: The 1198th Operational Evaluation and Training Squadron was a unit at Norton Air Force Base, San Bernardino, California from 1965 to 1972 which conducted the initial testing of Lockheed C-130 Hercules transports modified for special operations. This went on under the project names of Thin Slice and Heavy Chain which led to the MC-130 Combat Talons, still a key component of Air Force Special Operations Command.[1] Its initial commander was Lt. Col. Robert Marks. 

More at the link  

https://en.wikipedia.org/wiki/1198th_Operational_Evaluation_and_Training_Squadron