Loose Ariel Connection AWA Model PDC-61001?

My father has just purchased an AWA LCD TV/DVD Player Model PDC-61001
The Telescopic Antenna is very loose & the antenna will not stay Vertical. I can not see any way of adjusting the Arm. Does it have to be tightend up from the inside of the unit. This is Brand New out of the Box. Hope you can help me.
Kind Regards,
Graham Roberts Melbourne. Australia