Model: IC-735 Bulletin: B1604 Subject: Elimination of chirp in CW mode when operating a wide split Information: This modification was incorporated in all IC-735s after S/N 16801 1. Remove the top and bottom covers. 2. Remove the main board. 3. Add a tantalum capacitor 1.5 mf 35V with the positive lead to the collector of Q42 and the minus lead to the emitter of Q42. The ICOM part number for the capacitor is 918-05090. 4. Add a tantalum capacitor 2.2 mf 16V with the positive lead to the base of Q62 and the minus lead to the emitter of Q62. The ICOM part number for the capacitor is 918-01674. NOTE: Spurious emission will result if the capacitors are installed with incorrect polarity. 5. Check the value of R106 on the main board. It should be 22k. 6. Replace the main board in the radio. 7. Remove the PL board from the radio. Replace the components on the following list. Original New ICOM Part Value Value P/N C29 .001mf 50V 470pf ceramic 918-01578 C30 .1mf mylar .022mf mylar 918-01686 R105 220K 47K 915-01183 8. Reassemble the radio.