A TDMA radio terminal comprises a transmitter portion and a receiver portion. A reference signal is launched in the transmitter portion while tuning the receiver portion. At the same time, an internal delay counter is started. The counter counts clock pulses till the reference signal returns through the receiver portion. Letting this pulse count be Nd, a transmission wait time is Nt-Nd. Nt is a transmit timing at the antenna. The Nd counting operation may be triggered by a power on or a signal from a controller. Method for determining the transmission wait time in the production site is also disclosed.