Date: 17 May 90 15:54:21 GMT From: hpcc01!col!kenw@hplabs.hp.com (Ken Wyatt) Subject: IC-24AT Receive Mods At the request of several interested hams, I am posting the modification instructions for the Icom IC-24AT. This set of instructions originated from Icom America and was downloaded from the Icom Library of HamNet (Compuserve). Ken WA6TTY (kenw@col.hp.com) ----------------------------------------------------------------------- IC-24AT Undocumented Features - (from ICOM) The IC-24AT dual band handheld had three additional features that are not described in the owners manual. These have been left out of the owners manual because some countries restrict the use of the radio in these modes. AM AIRCRAFT RECEIVE PLUS 740 to 960 MHz RECEIVE Remove D13 from the main logic board (this diode may already be removed by ICOM in some units). This diode may already be removed in some radios. D13 is on the main logic board and is a discreet diode (one of the two in the radio) near the center of the board. It is the left discreet diode of the two on the board when the radio is open and held with the controls away from you. Simultaneously hold "Light", "B", and "#" keys depressed and turn power on. It is important to note that the radio will not meet specifica- tion on the out of band receive frequencies that are enabled with this modification. DIRECT KEYBOARD ENTRY of 100 MHz FREQUENCY Simultaneously hold "Light" and "3" keys depressed and turn power on. CROSS BAND REPEAT (simplex) Remove D14 from the main logic board (this diode may already be removed by ICOM in some units). The diode is a discreet diode to the right of D13 (from above) and directly beside it. Simultaneously hold "Funct" depressed and push "C". To turn on cross band repeat: Hold "Funct" depressed then push "5" and then push "D". To turn off cross band repeat simultaneously hold "Funct" and "D" depressed. 2-14-90 ------------------------------