Subject: IC-2SAT TX/RX mod Here's the straight scoop and I HAVE tried this but you still proceed at your own risk Take the battery cover off the bottom and remove the two screws. Remove two screws directly behind PTT button. Remove one screw where handy-carry strap goes. Gently pull on the front half of the radio and the radio will split apart but don't pull TOO far because the front half of the radio is still attached to the back half with that flexible plastic film wiring stuff. Fold front half to the right and lay it down. WARNING: The battery//cover release button can now pop out and a little itsy-bitsy tiny spring can take off for parts unknown. (Ask me how I know this... I spent 2 HOURS looking for that little sucker!) Pull the button out of the case NOW and watch out for that blasted little spring! All work is done on the circuit board inside the FRONT half of the radio (the part that you just pulled off). EXTENDED RECEIVE: Look along the RIGHT side of the circuit board and about halfway down the right side you will see a tiny circuit board that is mounted VERTICALLY on it, aligned from top to bottom. Look at the TOP of this little tiny board and you will see a normal diode (D-9) that is vertically mounted on the vertical board. Sounds confusing, but you can't miss it, it's right on the top end of the board. Cut this diode. Don't try to unsolder it... CUT IT. Take my word on it. WARNING: Don't pull the diode away from the board and leave it hanging. When you put the radio back together it is a very close fit and if you short the diode, the radio won't work. The PLL stays unlocked but no damage will occur. (yeah, I did that too :-) If you stop right here and reassemble the radio, you will now have extended RECEIVE capability after you reset the radio according to the instructions in the manual on the first page. And it REALLY is extended. My PLL was still locked up down around 88 Mhz and actually received FM broadcast stations although it obviously sounded BAD! :-) The radio freq. read-out now will go all the way up past 1 GHz, but that's just the dial read-out, check the Channel Indicator and when it goes to a "U" for "Unlocked" you can keep an eye on PLL performance, however I was amazed at where the PLL was locking up and the fact that it was actually receiving (albeit poorly) across a very very wide range. Yes, of course the sensitivity is way down the further you wander from the 144-148 design frequency range but it still is pretty impressive, and the new freqs. can be stored in memory and scanned. EXTENDED TRANSMIT: Look for the big IC directly in the middle of the main board on the front cover (IC-1 40608). Go to the bottom right corner of it. Move your eyes slightly to the right and you will see three chip resisters in a row. Just to the right of THOSE you will see three silk screened dots that are bracketed by a rectangle of white ink lines where a factory diode package would have gone. The "dots" form a triangle with one at the top and two at the bottom. Install a diode (1N914 or equivalent) with the cathode on the TOP dot and the anode on the bottom left dot. This will give you extended transmit from about 138-163 or so. But if you believe that trying to get a diode in there (without shorting out a lot of stuff) is impossible, (and you are very close to being correct) then FORGET this approach. Instead get Icom's diode DA (# 1750000160) and install IT in the same place. I tried using the 1N914, and it was a TOUGH job. It worked but looked horrible and was in imminent danger of falling off. I tried it out, verified that it worked... and pulled it right out. I have the diode DA pack on order now and will do it right when it gets here. I would politely suggest that you forget trying to use the 1N914 unless you have a micro-miniature repair facility at hand. (I did and still didn't like it). ============================================================================== A friend of mine in Germany mailed me a *very* intriguing photocopy of a letter he received from someone who works for Icom-Europe. It's an internal ICOM memo with details on how to do all sorts of nifty tricks with the IC-2SE (which may nicely translate to IC-2SAT tricks). I have attempted to exactly duplicate the memo below, mangled spelling, unclear passages, and all. I don't have an IC-2SAT service manual yet, and so I'm not qualified to say if this is all really applicable or not. And, the German at the closing is a mystery. I typed "fu:r" to indicate "fr". Anyone with more details, please let us know! Bob Cromwell KC9RG cromwell@ecn.purdue.edu ps: For the people asking "what was your original diode matrix, that appears at the end. There was some thought that the matrix programming changed after the first few (hundred? thousand?) models. This is from the schematic that came with mine, with serial number in the 9500's. ICOM ICOM (Europe) GmbH Himmelgeister Strasse 100 4000 Du:sseldorf 1 F. R. Germany Phone: 0211 / 34 60 47 Fax: 0211 / 33 36 39 Telex: 8588082 ICOM D To: Icom Dealer Dusseldorf, 14.4.89 I C O M S E R V I C E I N F O R M A T I O N I C - 2 S E Push Key + switch on Requested Mode Remark LIGHT + MON CPU RESET Clear all Memories LIGHT + FUNC FULL DISPLAY Display Func Test ---------------------------------------------------------------------------- LIGHT + V/M SIMPLE MODE Info on Equipment LIGHT + C (SCAN) MULTI-FUNCTION MODE Details in Handb. ---------------------------------------------------------------------------- LIGHT + FUNC + V/M RECEIVER MODE (All Band) All Band - no Tx ---------------------------------------------------------------------------- 1. Start SIMPLE MODE TRANSCEIVER MODE/ Tx only HAM-Band/ 2. Light + FUNC + C multi-function mode Rx see list below ---------------------------------------------------------------------------- Extent Transmitter Install Diode AD (D6) Tx: 139-163 MHz (FM) Manual AM/FM Mode Change all Bands: Rx Band Ranges: 1. Change to RECEIVER MODE (not receive mode) 75 - 106 MHz (FM) 2. FUNC + PTT (working in RECEIVER MODE) 108 - 130 MHz (AM) 138 - 169 MHz (FM) Note: (+) 174 - 192 MHz (FM) 1. keep pushing each key at same time, 204 - 243 MHz (FM) 2. switch on equipment, 250 - 291 MHz (FM) 3. hold (about 4sec.) until "SET" appear, 310 - 370 MHz (FM) 4. release keys and requested mode appear; Easily tunning step change (5 - 50 KHz): 1. push and hold FUNC key for 2sec. 2. rotate TUNING CONTROL. 3. Push FUNC to return to previous mode. Frequency ranges are appoximately and not garantied. Receiver sensitivity garantied only in HAM-Band (144 - 146 MHz). In RECEIVER Mode equipment running exclusively as a Receiver, cannot transmit at all. Achtung: nur fu:r den Fachha:ndler zum Zwecke des Service bestimmt. Es mu:ssen die Bestimmungen des Fernmelde-Anlagengesetz heachtet werden. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [page 2] IC-2SA/E Frequency range expantion * Remove any diode position on D6 * Install diode DA (code No. 1750000160) position D6 After this modification frequency lock range will be expand typicaly : RX (MHz) : 108 - 140 (AM) , 138-169 (FM) , 310-370 (FM) , TX (MHz) : 139 - 163 (FM) , ------------------------------------------------- | | | | | | | | | R R | | 3 3 | | 9 8 | | o | | R R R ### <--- | | 4 4 4 ### | | 1 2 3 o o R | | 6 | | ___________ 1 | | / \ | | / \ | | | SP1 | | | | | | | | | | | \ / | | \___________/ | | | ------------------------------------------------- >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [explanation of page 2] Yeah, the above is crude, just meant to give the relative locations of the mysterious diode, SP1, R38, R39, R41, R42, R43, and R61. The 3-terminal box with an arrow drawn to it (the arrow is in the original image) looks like the below. A diode is connected from the lower left tab to the upper tab. ___ | | -------------------- | / | | --- | | /_\ | | ____| | | / | | | | -------------------- | | | | --- --- >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [diode matrix programming] To simplify/fool-proof this, if the schematic has: (X) --->|--- (Y) I'll say "from X to Y". From the "IC-2SAT IC-2SET SCHEMATIC DIAGRAM": Japan Version D6: DA115 from KEYI2 to KEYS2 Europe Version D5: DA115 from KEYI0 to KEYS3 D6: DA115 from KEYI2 to KEYS2 Italy Version D5: DAN202U from KEYI1 to KEYS3 and from KEYI0 to KEYS3 D6: DA114 from KEYI0 to KEYS2 U.S.A. Version D4: DA115 from KEYI2 to KEYS3 D9: ISS254 from KEYI1 to KEYS2 Australia Version D5: DA114 from KEYI1 to KEYS3 D6: DA115 from KEYI2 to KEYS2 Asia Version D4: DA115 from KEYI2 to KEYS3 Now, can anyone use this to figure out the Icom-Europe memo??? Bob KC9RG ============================================================================== From: kraft@perdita.gac.edu (Steven Kraft) Modifying the IC2SAT for extended receive is very simple if a certain diode was not installed at the factory, as was the case with my 2SAT. Turn the radio off, simultaneously press <#>,, and turn it on. (The button is not labeled, it is on the side under the wrist strap.) Release those three buttons after the radio beeps. (I think that mine beeped.) It can now receive over three large frequency ranges and will receive AM aircraft band transmissions acceptably. Experiment to find which frequencies you can get. The memory channel number will display the letter "U" to show that the PLL circuit is unlocked on frequencies that cannot be received. It will tune from 0-1300MHz but the operable ranges are not that big, its highest receiving freq is a little over 300MHz. If that doesn't work, a diode will have to be removed. It is a glass diode mounted on the PTT switch circuit board, and I think it is the only standard component in that area. It is mostly surface mount components.