The minimum Euclidean distance properties, upper bounds on the minimum distance, power density spectrum, and power-bandwidth tradeoff for M-ary phase codes where K different symbol lengths are used in a cyclical manner are considered. When these lengths are all related to each other as rational numbers, they give a finite-state Markov (trellis) description of the signal. Here, K=2 is assumed. It is found that from the point of view of minimum distance and spectral properties, multi-T phase codes are very similar to multi-h codes. It is also shown that quaternary codes give considerable improvement over binary codes. >