[MilCom] FM Radio aboard C-130(J)?

[KB5FAS at aol.com]

I live near Little Rock AFB. Today, while scanning the 138-144  MHz band for 
milcom activity at the base, I copied traffic on 138.950 FM from a  departing 
C-130 (Arrow 47) complaining to someone about an instrument  malfunction. He 
advised he was at 4,000 ft but was getting an low altitude  alarm. He advised 
that he thumped the instrument with his finger and  it corrected itself. I was 
watching the C-130 as it was climbing out of the base  to the west and moments 
before had copied his departure on 306.200 MHz. I  verified that it was FM 
instead of the usual AM from the aircraft.  

LRAFB recently took possession of the C-130(J) aircraft and have had  crews 
training extensively on the new model "J". Perhaps they have FM onboard to  
speak with ground crews during the test flights? Anyone familiar with any FM  
equipment inside the C-130(J)'s? 
 
Thanks in advance.
 
Joe KB5FAS
Central Arkansas