[TenTec] a TenTec microphone by: Heil

[Bud Berthold via TenTec]

I have a TenTec microphone by: Heil.........It has a black (rather  heavy) 
metal casting case and a heavy grilled head similar to the 708 with TEN  TEC 
on the case....It also has a square PTT button 
 

I have not been able to find any information on it.....
 

Can anyone help...
 

73
 

Bud W2GLN
 

PS. I'm a proud new owner of a BEAUTIFUL ORION 565AT...I love it  :-)