Transmitting on 18.1145 MHz causes a spur to appear at 18.1150 MHz with the antenna tuner on.
Add the low pass filter shown in the accompanying diagram to the input circuit of mixer Q41 on the IF unit (X48-3060-00). This filter will increase the attenuation by approximately 20 dB.
Qty Description New Part No. Circuit Description
1 220 µH inductor L40-2211-14 NA
1 220 pF chip capacitor CC73FSL1H221J NA
Caution: This modification requires soldering equipment rated for CMOS type circuits. It also requires familiarity with surface mount soldering techniques. If you do not have the proper equipment or knowledge do not attempt this modification yourself. Seek qualified assistance from your closest Kenwood Service Center (Long Beach, CA, or Virginia Beach, VA).
Time required for this modification is 60 minutes or less.