An active phased array radar with distributed low-peak-power transmit modules requires pulse compression to provide high sensitivity and fine range resolution. A long transmitted pulse, however, has accompanying problems such as a near-range blind zone for the transmitting channel and a loss of other gate data (dead gates) in other channels for a multichannel system. In this report the trade-off between the benefits and costs of pulse compression (lengthening) for multifunction phased array radars (MPARs) are analyzed. Specific results are presented for a three-channel MPAR and a two-channel terminal-area MPAR (TMPAR) that have been proposed as replacement systems for current U.S. civil-sector aircraft anad weather surveillance radar systems. The recommended maximum compression ratio is 130 ofr the MPAR and 80 for the TMPAR. The results are independent of radar peak power and antenna gain, and represent upper bounds. Acutal pulse compression ratios that would be employed are likely to be somewhat less tha these values, based on fulfilling specific sensitivity and scan-time requirements with specific radar physical parameters.