Noise is generated when NB1 is switched on for the sub-receiver.
Switching noise from the noise-blanker gate enters the AF amplifier via the +15 V line causing the noise.
Qty Description Kenwood Part No. Circuit description
1 100 µF, 16 V electrolytic capacitor CE04KW1C101M NA
1 120 ohm resistor RD14BB2B121J NA
- Cut the pattern of the 15 V line on the IF unit (X48-3060-00) component side, near Q34's emitter and add the 120 ohm resistor as shown in the accompanying diagram.
- Add the electrolytic capacitor as shown in the diagram. Quickly solder the negative lead to the metal shield of L28.
Time required for this modification is 15 minutes or less.