The first was out of an old GE Exec II base. This is my second successful system that I've built. I've installed a heavy-duty fan that sends air straight across the fins of the TX radio. Do not forget to set the squelch control in the settings screen of csf300.exe Exit from the program and your radio is now tuned. This will tune the receiver front end for the best value for the frequencies chosen. Set the curser at 'D/A BP T1' and press 'F9'. Usually 'adjust /A /1' (do not tpe the ') works fine. You will be given 4 switches to select the program. You will now have to run a program called 'adjust.exe'. Once you have programmed your radio you now have to tune it.

Now program in the frequencies you want to use. Please note, the low-split (400-430 MHz) version only goes up to approximately 455 MHz. Use this program to determine the range you want to use with this radio. Using the program csf300.exe program your frequencies. I DO NOT PROVIDE THIS SOFTWARE! It is available on the 'Net'. You will also need a copy of ICOM Software CSF300 that you can use to program the frequencies and adjust the radio receiver. To adjust the radio in software you will need the following cable: OPC478+OPC592 The OPC592 is a special jumper cable that goes on the end of the OPC478 and connects to the mic jack of the F420. Just to make sure, change to your lowest operating frequency and make sure your radio still oscillates. You may have to make a few tranmissions adjusting slowly until you get the vco to lock. Then transmit at the highest frquency and adjust the tx vco for no more than 7.75 volts. Increasing the slug brings the lock voltage down. Adust to the highest frequency that you wish to tune and set it to just less than 7.75 volts with a high impedence voltmeter. Then locate a point marked 'cp1' just to the left of that can. The Rx Vco is at the top away from you and the Tx Vco is below that. Locate the Tx and Rx VCOs, they are on the left side of a rectangular metal piece. Open the bottom of the radio and place the front of the radio towards you. There is a hardware change and a software change. The radio is capable up operating at higher frequencies for a maximum bandwidth of 30 MHz. This radio is a 440 MHz workhorse supplied in the 400-430 MHz Range.

Icom ic-f420-10 programming software