KWM2/2A Service Bulletin Information

KWM-1 Transceiver
PUB NO.	NOTE	DATE	 DESCRIPTION
SB 1		9/12/58	 A. Improvement in calibration Operation B. Spurious Outputs of KWM-1 C. Transient in speaker when switching from receiver to transmit D. Hum in speaker when AF gain control is advanced in CW operation E. "Tweets" in audio output caused by DC power supply

KWM-2 Transceiver
PUB NO.	NOTE	DATE	 DESCRIPTION
SB 1			 Not Issued to KWM-2. Issued to KWM-1!
SB 2	 	8/8/60
                Revised
                10/1/60	 Add VOX Relay Time Constant Control
SB 3	 	7/12/60
                Revised
                10/1/71	 Correlation Between Frequencies on Different Bands
SB 4	 	9/2/60	 Improvement of ALC Action and Elimination of ALC Overshoot
SB 5	 	11/23/60
                Revised
                1/3/61	 To Improve Transmit-Receive Exciter Tuning Coincidence
SB 6	 	1/11/62	 To Eliminate Delay in Operation When Switching From Transmit to Receive Function
SB 7	 	4/11/67
                Revised
                10/27/67
                2/1/70	 Replacement Relays K2 and K4
SB 8	 	9/1/70	 A: Eliminate AGC Overshoot in Noise Pulses and Provide Dual Time Constant Action B: Change Source of Delay Bias to the AGC Rectifier C: Add Delayed Decay (Hang) AGC to the RF Amplifier
SB 9		6/15/72
                Revised
                4/15/73
                10/15/75 Convert KWM-2 to KWM-2A
SB 10	 	4/15/74	 Eliminate VHF Parasitic Oscillations in Tone Oscillator, V2B
SIL 1-75	10/15/75 Overcome Instability Caused By Aging
SIL 2-75 	10/15/75 Extended Operating Range
SIL 0-60	2/3/60	 VFO Oscillator Drift
SIL None	11/15/60 Servicing Information

KWM-2A Transceiver
PUB NO.	NOTE	DATE	 DESCRIPTION
SB 1			 Not Issued
SB 2	 	8/8/60   Add VOX Relay Time Constant Control
SB 3            Revised
                10/1/60	 
                Revised
                10/1/71  Correlation Between Frequencies on Different Bands
SB 4	 	9/2/60	 Improvement of ALC Action and Elimination of ALC Overshoot
SB 5	 	11/23/60
                Revised
                1/3/61	 To Improve Transmit-Receive Exciter Tuning Coincidence
SB 6	 	1/11/62	 To Eliminate Delay in Operation When Switching From Transmit to Receive Function
SB 7	 	4/11/67
                Revised
                10/27/67
                2/1/70	 Replacement Relays K2 and K4
SB 8	 	9/1/70	 A: Eliminate AGC Overshoot in Noise Pulses and Provide Dual Time Constant Action B: Change Source of Delay Bias to the AGC Rectifier C: Add Delayed Decay (Hang) AGC to the RF Amplifier
SB 9			 Not Issued
SB 10	 	4/15/74	 Eliminate VHF Parasitic Oscillations in Tone Oscillator, V2B
SIL 2-75	10/15/75 Extended Operating Range

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