MULTIPLEX SINGLE CONVERSION RECEIVER CRYSTAL 36MHZ CHANNEL, 601, 603, 605, 606, 607, 609, 611, 613, 615, 617, 619, 621, 623, 625, 626, 627, 629, 631, 633, 635, 637, 639, 641, 643, 645, 647, 649, 651, 653, 655, 657, 659.