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A post NE1H (now N1IP) and I (now K4JCW) wrote from around Feb, 1998 describing how to modify an Icom PCR-1000 for cellular coverage.
If I recall correctly, radios with S/N's > 4000 can no longer be modded this way.
RADIO: ICOM IC-PCR1000 COMMUNICATIONS RECEIVER. SUBJECT: ICOM IC-PCR1000 FREQUENCY MODIFICATION. You've been waiting. You've been told it can't be done. You don't want to pay for it. Here's how you do it. The PCR-1000 full coverage mod: What you'll need: Small philips screwdriver Slightly larger philips screwdriver Soldering iron with *very* fine tip Xacto knife, or other sharp tool 2 0-ohm surface mount resistors, 0804 in size, or 30 gauge wire-wrap wire No fear of surface mount components Ability to follow instructions Very very very first step. Read ALL the steps before starting. Make sure you feel comfortable making a mod of this nature. It's not rocket science, but it does require a steady hand. There are three things that can happen as a result of this mod. 1) You're completely successful. 2) You screw up a surface mount pad, but the radio still works when you're done. 3) You're a total hack using the wrong tools, and you send the radio back to Icom for repair. Hopefully, you're a result 1 type person. At worst, you're a result 2. If you think your going to be a result 3 type, don't even start. Call a friend. We've done this mod on 2 radios with complete success. We can't guarantee that in later radios this mod will still work. It works at least with serial numbers up to 1111 in the last 4 digits. Let's get started! Remove the 8 screws that attach the cover, and remove the top cover of the radio. Orient the radio so that serial, power and RF connector are closest to you, and the power switch faces away from you. On the PC board closest to you, in the upper left hand corner you should see a 80 pin surface mount chip. It has a number such as 64F3334 stamped on it. This is the processor. Near the upper left hand corner of the chip, you should see 2 small green 0-ohm resistors. To the left of the two resistors you should see an unpopulated pair of pads. These are the 3 "R"s below, on the left. The 4th "R" is used for location reference below. | RRR R | o ooo | o ----------------- | o | | | o | | D | | | D | r | | | ----------------- | | --- | | | | | | | | | | --- --------------------- (Picture courtesy of Alan Adamson, NE1H) Using the soldering iron and knife, *carefully* remove the right hand resistor. You'll need to alternately heat the two ends, while apply a *light* pressure with the knife. Once it's hot enough, it will lift off. It's very easy to destroy the pads the resistor is soldered to, so be *careful*. You'll now need to short the pads of the left resistor (this is the unpopulated one). You can either try and re-use the resistor you just lifted (least good idea), short them with a short piece of wire wrap wire (OK idea), or use a real 0-ohm resistor (best idea). For the next step you have two options. One option is easy and does not require removing the board from the radio (recommended). The other option is "more correct", but will require disconnecting all the cables, removing the 5 screws that hold the board down, etc (purist method). We'll presume you're more likely to want easy, so here are the steps for it. Keeping the radio oriented as described above, look below the right hand resistor (the one we removed). You should see 3 vias (holes) (see picture above). Follow the left most via, and it should go to the left most pin of the processor. The second via should go to the next pin to right, and third via should go to the pin to right. At this point, you should see two pins that don't appear to be connected to anything, then a pin that connects to a small black resistor marked 201 (this is the 4th "R" in the picture). If you've sucessfully located the 6 pins above, we want to short the pin that is the 4th from the left to ground. Above these 6 pins, you should see a small black rectangle, with 8 pins. I believe it is marked 220. On the side of this part (it's a resistor pack), there is a pin that is soldered to the ground plane. To short the 4th pin from the left to ground, tack a wire to the pin. Be *very* careful not to short the adjacent pins to the 4th pin. It's very easy to do. It you do, use a piece of Solderwick or coax braid to remove the solder. Better yet, don't short the pins. Tack the other end of the wire to the pin on the resistor pack described above. OK, you'd rather do it the "more correct" way. Disconnect all the cables from the board. You'll need to remove the shield from the RF section to remove the white ribbon cables. Disconnect the power and speaker cable. Remove the 5 screws that hold the PC card down. Remove the card from the radio. Orient the board as described above. Look for the white connector above the packet connector (lower left). It's marked J12. Just above that are a pair of solder pads for a resistor. One side goes to ground, the other goes to a via. Follow the trace on the bottom side of the board. You should see that it goes to a via, but that the trace has been cut right next to the via. Using a sharp knife and a lot of care, scratch away the solder mask to reveal bare copper on the trace. Use a piece of wire wrap wire to repair the cut trace (bridge the trace to the via). Back on the top side, short the pads for the resistor that are open (this is the lower case "R" on the left, off by itself). Reassemble the radio. If you used the "more correct" way, make sure you get all the screws and cables back in. Plug it in, turn it on, fire up the software. Tune a frequency you couldn't before. If you can tune it with the software, and the squelch is open, you're working! If it's not working, review everything we described. Make sure you didn't short any pins. I can't offer you much more help if it didn't work. Remember, you screw up your radio, it's not my fault. I don't work for Icom, I don't represent Icom. I don't endorse listening to frequencies you're not supposed to, and can't be held liable for anything that happens, anywhere in the universe, as a result of you making this mod, or even thinking about making this mod (Gawd, I hate lawyers. CYA!). This mod was done completely from our own experience and background, and did not reference any material. We don't know about these people selling the mod on the 'net, but we didn't steal it from them. Hope this helps. If you've got any suggestions to improve how to make this mod, please send e-mail. If you made this mod, let us know how it went. Also, if you want a list of the PCR-1000 commands we know about, drop us e-mail, or use DejaNews(tm) and search the alt.radio.scanner groups for the post (look for PCR-1000 in the subject). - Chris, KD4DTS (Thanks to Alan Adamson, NE1H for his being ready and willing to sacrifice his radio to a higher cause, and his drawing). --- John "Chris" Wren, KD4DTS firstname.lastname@example.org xxx-yyy-zzzz (H) 770-840-9200 x2417 (W) By US Code Title 47, Sec.227(a)(2)(B), a computer/modem/printer meets the definition of a telephone fax machine. By Sec.227(b) (1)(C), it is unlawful to send any unsolicited advertisement to such equipment, punishable by action to recover actual monetary loss, or $500, whichever is greater, for EACH violation.