I currently own 624, 625, 641 and 642 base rigs plus a parts 642, along with two 639 mobiles - which used the same chassis as the 642. My only gripes: Being single conversion and with an IF stage which has just the right LO frequency, the receivers are prone to image response from SWBC stations in the 41M (7MHz) band. And do resist the temptation to 'peak' these rigs, especially if using an antenna which exhibits a high VSWR. They don't incorporate an effective power-foldback circuit and it's relatively easy to cook the final transistors.