This file is meant to replace the old PRO-43 mod file. 17.12.92 Subject:cellular (870-890 MHz) and low band (51-88 MHz) restoration for PRO-43 From:armille@afterlife.ncsc.mil (A. Ray Miller) Summary:cellular (870-890 MHz) and low band (51-88 MHz) restoration for PRO-43 A few people have mentioned the cellular mod for the PRO-43; it turns out you should not remove but MOVE the diode. Doing so allows cellular coverage as well as low band (up to 88 MHz) coverage. Acknowledgments to Grove Enterprises; this information came from them. They are selling the PRO-43 for $300 which is $50 less than Radio Shack. I have no connection with them other than as a satisfied customer. PRO-43 Cellular Frequency Restoration and Low Band Expansion Note:It is not lawful to monitor cellular or conventional mobile telephone conversations. The following procedure requires familiarity with microcircuit soldering and will violate your warranty. Grove Enterprises assumes no liability resulting from its attempt, nor will accept the modified scanner for return under any condition. TOOLS NEEDED:Fine point, low power soldering pencil; solder wick or a desoldering tool; pointed awl, hemostats or pointed tweezers; small Philips screwdriver; solder. 1) Remove the battery, antenna and back cover (held in place by four screws). 2) Remove the six screws holding the top circuit board in place. Carefully unsolder the two antenna connections from the board. Bend the antenna ground tab fully up from the board. Carefully lift the board, unplugging the black connector at its base, and lay the board out of the way on its bundle of colored wires. 3) Remove the two screws from the next board and lift it, carefully unplugging the white connector at the bottom of the board. Lift it up and lay it aside on its brown wire (which can be unplugged if necessary). 4) Unsolder and remove the metal shield from the final board, revealing the microprocessor; note the row of diodes labeled D1-D5 above it. Only diodes D1, D2, and D4 are present; assisted by a pointed tool, unsolder and remove D4, the lone diode (this restores cellular frequencies which will be searched in 30 kHz steps). 5) Resolder the removed diode carefully into position D3 to extend low band coverage to 88 MHz. 6) Reassemble the boards, paying particular attention to the alignment of the plugs. Test the radio by entering any frequency between 870 and 890 MHz (cellular) and 51-88 MHz (low band). -- A. Ray Miller arm@super.org | armille@afterlife.ncsc.mil ================= From:ross@novax.llnl.gov Date:19 Aug 92 16:51:08 GMT Here is my keypad beep delete mod for the RPO-43: 1. Remove battery. 2. Remove back cover (4 screws). 3. Remove top board (6 screws, desolder two antenna connections and bend antenna ground lead up out of the way). Be careful of black connector at bottom of board. Flip board over and lay aside (wire connectors need not be disconnected). 4. Remove middle board (remove 2 screws and wire connector). Be careful of two multi-pin connectors along underside of board. Set middle board aside. 5. Locate 10 pin connector on side of bottom board (labeled CN3). Note that one end of connector has pin 10 labeled as such. Count back to pin 6 and bend pin 6 ninety degrees towards the large RF shield. Make sure the bent pin clears the RF shield. 6. Reassemble and your done OR do the cell mod since you are so close. Have fun. Gary Ross >usual disclaimer> ------- Subject:Improved audio for the PRO-43 portable scanner From:parnass@cbnewse.cb.att.com (Bob Parnass, AJ9S) Date:Wed, 2 Dec 1992 01:15:35 GMT IMPROVED AUDIO FOR THE PRO-43 SCANNER by Bob Parnass, AJ9S The Radio Shack PRO-43 scanner audio is too bassy.1 The lack of treble makes it difficult to hear the PRO-43 in noisy situations, especially whilelistening in a car or truck. LouisShirleysent mea schematic andsug- gested I remove C341, a tiny 0.015 ufd surface mount capacitor. I'm glad to reportthat removingC341 made a great improvement. The audiois nowmuch "crisper,"more like the Uniden 200xlt, although still not quite as loud. Turning the volume control up still overloads the PRO-43's small, internal speaker, but there'sless need to dothat once C341 is removed. The PRO-43contains 3 printed circuit boards, and the middle (second) board containsthe audio circuitry. Finding C341 is difficult,as it is neither markedwith avalue nor a component designation. It is located on the foil side of the middle board, under IC304, an LM386 amplifier IC. C341 is in parallel with, andphy- sically next to, R350 (33,000 ohm). R350is slightly larger than C341 and is marked 333. Both R350 andC341 are connected between pin 2 of theLM386 and ground. A Note About 50-88 MHz Reception Now that Ihave a schematic, I see that the European version of the PRO-43 has different coils and capaci- tors in the low (mid) band front end filter.That explains why the 75 MHz sensitivity isn't stellar after adding diode D3 toenable 30-88 MHz coverage. __________ 1. See"PRO-43ProductReview," by BobParnass, AJ9S, in theNovember 1992 RCMA Journal. -- ============================================================================== Bob Parnass, AJ9S - AT&T Bell Labs - parnass@ihlpm.att.com - (708)979-5414 ============= Compiled for garfield.catt.ncsu.edu by: Brad Steinman University of Toledo Computer Services cscon0151@uoft02.utoledo.edu  Amsterdam View Our Stats   CLICK FOR A FREE DOMAIN NAMES HTTP://WWW.YOURNAME.TK FOR YOUR OWN WEBSITE IF YOU CLICK HERE AND YOU CAN VOTE FOR OUR FREE WEBSITES IN THE TOP 100 LIST  WANT A TOP RANKING ? USE THE ULTIMATE SOFTWARE SUITE FOR WEB SITE PROMOTION  FreeWebSubmissions Submit Your Site To The Web's Top 50 Search Engines For Free THE ALEXA BANNER, THIS BANNER GIVES THE DALLY STATISTICS OF THIS FREE WEB SITE The World of Free Packet Radio Software Amsterdam The World Of Free Packet Radio Software Amsterdam The Netherlands |