Msg# TSF Size #Rd Date Time From MsgID To 3176 BN 4389 1 18-Jun 2026 KA2HZO 31351_KA2UGQ ALL@ALLBBS (NONE) Sb: ICOM 02AT FREQUENCY MODIFICATION icom 02at mod 140-163 mhz a. locate a copy of the june 1986 issue of 73 mag. b. the article on pg. 60 is for models with id numbers lower than 35,000. if yours is one of the newer models like mine..... then follow these changes: 1. read the entire article b-4 doing anything!!! 2. follow steps 1 to 3 on pg. 61 "modify ur 02at" then s t o p ! refer to fig.2 on pg. 60 and remember the diodes on urs are in different locations than in the pix. 3. using a very small flat blade iron and some solder wick remove the the three leg diode d2 notice that the numbering for d1,d2,d3,d4 are off to the left of the actual location of the diodes on the board. 4. resolder d2 down in position d5 try to use the solder on the pads.. only add solder to the pads if absolutely necessary, b-4 you put the diode in place to avoid bridging. 5. solder a store bought 1n914 or 1n4148 diode from the top pad to the bottom left pad of d4. you will need to bend and cut the leads of the diode and pre-tin with solder. bend the leads of the diode so that the body of the diode across the bottom right pad covering it up. the banded end ohe the diode should be facing down towards mhe bottom right pad. now you are ready to follow steps 7 to 13 and the rest of the instructions in the article. the only difference you will find is that a letter "u" will flash to indicate unlocked instead of the entire display flashing. gud luck and enjoy the fruits of you labor. if you are unable to locate the article pls send sase to: ka1ghf po box 1397 leominster, mass 01453 73's de ka1ghf "peter" RELAYED BY...N0KGX...GENE BAND EXPANSION MODIFICATION FOR IC-02AT FOR SERIAL NUMBERS ABOVE 34000 BY LTC STEVE PETERS, CAP ------------------------------------------------------------------------ 1. Remove back from radio (5 screws) and bottom plate (4 screws). 2. Carefully remove radio chassis from front case by pulling out top of radio and lifting slightly (to remove battery contacts from bottom case). Be extremely careful of ribbon cable and heat sink compound on power amplifier module. 3. Remove diode D2 from matrix board. 4. Add diode D4 (any small diode 1N4148; 1SS211). 5. The following is a schematic of the matrix board: ADD D4 REMOVE D2 I--+ --+-- --+-- + V D4 ID3 I ID2 I D1 I I I I I + + +---+ +---+ + + 6. Install radio chassis back into front cover. Leave back off temporarily. 7. Carefully apply power to radio and enter the lowest desired frequency. 8. Adjust slug through bottom hole on VCO cover for .5 VDC at VCO test point (just below VCO shield) at lowest desired operating frequency. 9. This completes the modification. A few words of caution: 1. The radio is not type accepted for use in the commercial band. 2. Make sure you reinstall the battery latch correctly on bottom of radio or battery will become permanently locked onto radio. 3. Tighten screws on bottom of radio snuggly. If they loosen while battery is connected you cannot remove the battery. (This has happened to many units and it would be prudent to periodically check these screws to assure their tightness.) ------------------------------------ ***->Be careful not to transmit out-of-band, or accidentally operate on any non-amateur, unless you are authorized to do so. DO NOT JEOPARDIZE YOUR LICENSE! RELAYED BY...N0KGX...GENE Note: I haven't tried or verified this, proceed at your own risk. WA2ISE And do not transmit outside of legal bands!