copied from packet From: kd6th@kd6th.nj.usa (reqfil) Message-ID: <19567@KD6TH> INFORMATION ON THE HR2510 10 METER RADIO ------------------------------------------------------------------------- 1: THE HR2510 USES A DRIVER AND FINAL IN CONJUCTION TO GIVING YOU FULL 25 WATTS ON SSB. 2: THE DRIVER IN THE HR2510 IS COMPLETELY INTERCHANGEABLE WITH THE FINALS FOUND IN MOST RADIOS LIKE COBRA(2000GTL) AND THE UNIDEN (710E) AND IT CAN HANDLE UP TO 20 WATTS OF POWER. THE DRIVER IN THE HR2510 IS (2SC2166). 3: THE FINAL IN THE HR2510 IS A (MRF477) IT CAN HANDLE ABOUT 50 WATTS OF POWER. THIS IS A FURTHER INDICATION THAT THE RADIO WAS BUILT FOR POWER. 4: THE HR2510 HAS (AN612) BALANCE MODULATOR WHICH IS THE SAME FOUND IN A COBRA (148GTL) CB RADIO. 5: THE HR2510 USES A (10 MHZ I.F.) LIKE THE COBRA (146GTL) CB RADIO. AS A RESULT, THE RECEIVE IS VERY SIMILAR TO THE 146GTL CB RADIO. 6: THE HR2510 INSTEAD OF USING COILS, LIKE THE JACKSON RADIOS. thE HR2510 UTILIZES A WIDE - BAND TOROIDAL TRANSFORMER AT OUTPUTS TO ELIMINATE TUNING AND GET THE WIDE BANDWIDTHS NEEDED TO OPERATE THE (26 MHZ TO 30 MHZ). ------------------------------------------------------------------ EXPANDED FREQUENCY COVERAGE FOR THE UNIDEN HR2510 ------------------------------------------------------------------------ THIS RADIO COVERS A FULL 26-30 MHZ WITH A SIMPLE 10-MINUTE CIRCUIT CHANGE. NO FURTHER REALIGNMENT IS EVEN NEEDED, SINCE IT USES BROADBAND TUNING AND WAS DESIGNED TO COVER ALL THIS RANGE IN THE FIRST PLACE. PRODCEDURE: 1: LOCATE PINS 34 AND 35 OF THE MAIN UP CHIP IC315. (CALLED "UC1201A", UC117", ETC.) THIS IS THE LARGEST CHIP ON THE SYNTHESIZER BOARD, PB121BB. 2: THESE PINS ARE GROUNDED ON THE HR2510 , BUT ARE TIED HIGH (5.0 VDC) ON THE EUROPEAN MODELS LIKE THE PRESIDENT LIINCOLN. ALL THATS REQUIRED IS TO BREAK THE GROUNDING PC TRACE AND TIE THEM INSTEAD TO A +5.0 VDC SOURCE THROUGH A PULLUP RESISTOR. 3: ON THE SOLDER SIDE OF THE SYNTHESIZER PCB, YOULL NOTICE THAT PIN 34 AND 35 ARE SOLDERED TOGETHER AND ARE CONNECTED TO THE MAIN GROUND FOIL. USING A RAZOR BLADE OR EXACTO KNIFE, CUT THE FOIL AT A NARROW SPOT TO BREAK THIS CONNECTION. 4: NOW NOTICE THAT THE LEFT-MOST PIN OF PULLUP RESISTOR PACK RR301 IS UNUSED AND GOES TO AN ISOLATED ISLAND FOIL PAD.(HOW COINCIDENTAL!) JUST TACK A SMALL JUMBER WIRE BETWEEN THIS PIN OF RR301 AND THE PAD OF IC315 PINS 34 AND 35, AND YOU'LL BE IN BUSINESS! --------------------------------------------------------------- OK ! ----------------------------------------------------------------------- YOU NOW HAVE A RADIO USEFUL NOT ONLY FOR 10 METER HAM OPERATION, BUT ALSO FOR LISTENING* TO THE KIND OF ROAD INFORMATION AND EMERGENCIES FOR WHICH CB HAS PROVEN ITSELF REPEATEDLY. THE INDICATED COVERAGE ON THE FRONT PANEL WILL BE: *don't transmit, this isn't a type accepted radio! BAND A = 28.000 TO 28.490 MHZ BAND E = 26.000 TO 26.490 MHZ BAND B = 28.500 TO 28.990 MHZ BAND F = 26.500 TO 26.490 MHZ BAND C = 29.000 TO 29.490 MHZ BAND G = 26.965 TO 27.405 MHZ BAND D = 29.500 TO 29.990 MHZ BAND H = 27.000 TO 27.490 MHZ BAND I = 27.500 TO 27.990 MHZ BAND "G" IS THE STANDARD CB BAND STARTS UP AT CH.9, 27.065 MHZ. (Note: I haven't tried this, proceed at your own risk. And..... ***DO NOT transmit outside of the Ham band!*** (you don't want to loose your license!) Use the above to listen only, or for use with a transverter. Or use with a dummy load, to generate test signals for checking receivers. WA2ISE) cmd: