is it posible to crossband from vhf to vhf? what i want to do is use my motorola HT on simpex send it to the mobile tm-v708 and have the mobile talk to the repeater. all i have seen is xband from uhf to vhf
No, it is not possible. It isn't able to receive a signal and re-transmit it within in the same band. (Hence it is called "Cross-Band Repeat"). In order to do what you propose, a second mobile or portable would be needed and a repeater device used to take the receive audio and transmit it through the mobile. Also note that the frequency used going to the vehicle cannot be the same as the frequency being transmitted to the repeater.
Hopefully someone else can verify this and correct me if I am wrong.