[Milsurplus] GRC 9 power question

[Greg Mijal]

Hi:
I got a GRC 9 with a handcrank box and a 24 vdc dynamotor supply.
I think the easiest way to get this puppy on the air is running the DY 105 24 vdc supply.
I have 24 vdc supplies running off of wall current but want to run the rig at Field day this year as a way to attract the club operators.
So my question is this: If I buy a  new 12 to 24 vdc converter, what size should I buy? What kind of in-rush current draw should I prepare for?
Thanks
Greg
WA7LYO
Kinston NC