Midland Radio SP-300 service manual Base Diagram PIN Description

MAXON

SP-300 HAND HELD

			BASE DIAGRAM							PIN DESCRIPTION
RF Power Amp									No Description
									1	Input
									2	GND
									3	Vcc (Pre Drive)
								7	4	Vcc Control (Drive)
							6
							5		5	Vcc (Final)
									6	Output
					4
				2	3				7	GND
				1		(VHF) P.A. Assy. P/N: 650-230-0012
						(UHF) P.A. Assy. P/N: 650-230-0013
RX Front-End
									1	Input
					GND				2	GND
				GND					4	B+(4V)
							1		5	GND
		GND					2		6
						4				Output
				5
				6	(VHF) Front-End Assy. P/N: 650-110-0012
					(UHF) Front-End Assy. P/N: 650-110-0013
RX/TX VCO									1	Gnd	9 Gnd	17	Gnd
9	8	7	6	5	4	3	2	1	2	RX Out	10 Gnd	18	Gnd
									3	Gnd	11 Gnd
									4	RX Vcc	12 Gnd
						R309			5	Gnd	13 TX Mod
									6	TX Out	14 Gnd
									7	Gnd	15 Tuning
10	11	12	13	14	15	16	17	18	8	TX Vcc	16 Gnd
TOP SIDE					(VHF) V.C.O. Assy. P/N: 650-030-0021
					(UHF) V.C.O. Assy. P/N: 650-030-0020
			12.8 MHz TCXO
				1					1	Modulation
									2	GND
									3	Out
					4				4	Vcc (5V)
		2
			3
		(VHF ONLY) TCXO Assy. P/N: 650-100-0002
								Page -40-
								May 2001