Icom - 9350 / 3040 Protocol Converter (ic9350)

This project is to develop a way to use a Codan 9350 or 3040 automatic antenna with an Icom radio. Most Icom radios support the Icom AH-4 ATU, so the approach is to design a protocol converter that converts the protocol used by the 9350 and 3040 to the AH4 protocol to allow full integration with the Icom radios that support the AH-4.

The ic9350 Protocol Converter uses the interface uses the radio's ATU interface in the way that Icom intended, and will not disrupt radio operation .


Not supported

Error conditions detected:


Table 2: STATUS  LED
Status Description Comment
Steady on Tune success  
1 flash Tune failed Tune fail signaled by 9350 / 3040
2 flashes START signal < 250ms RESET received from Icom
3 flashes /TUNE low prior to initiation Tested without internal pull-up - fault could be no connection to 9350 / 3040.
4 flashes Timeout waiting for /START, /TUNE at completion 25 second timeout
5 flashes Timeout waiting for IND 1000ms
6 flashes Timeout waiting for TUNE 1000ms

Table 2 shows the STATUS LED indications. Note the 25 second timeout waiting for START, /TUNE, /IND at completion of a tune process,


Table 2: Pin assignment of 6 pin radio connector on ic9350 for Codan NGTcable.
Pin Signal
3 /IND
4 +12VDC


Table 3: Pin assignment of 4 pin connector on Icom tuner interface.
Pin Signal
1 /KEY
3 +12VDC


Table 4: Pin assignment of Codan 8528 DA15 radio connector.
Pin Signal
11 /IND
12,13 +12VDC
14,15 GND



Fig 1: Assembled PCB

Fig 1 shows an ic9350 prototype constructed on a PCB design by Mark Kyle, VK4KZK. The boards are designed to take 4 Pole PC Mount Plugable Header  (Jaycar HM3104 and HM3124) for both radio and antenna connections (though in this prototype, the radio side is direct wired).

Fig 2: Complete ic9350

Fig 2 shows the ic9350 complete in a UB5 Jiffy box (box dimensions 83 x 54 x 31mm not including connectors etc). To connect to the 9350 / 3040, and standard Codan cable is used, the radio end connector is cut off and the appropriate four wires are terminated on the plugable header at the right hand side of the picture.


Fig : 3




Version Date Description
1.01 10/12/2007 Draft.
1.02 26/02/2017 Updated for v1.03 3040 support.

© Copyright: Owen Duffy 1995, 2021. All rights reserved. Disclaimer.