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hamradioversion3.0examsandprograms1992.iso
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hr2600.1
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1991-03-09
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HR2600.1
AFTER HOOKING UP MY HR-2600 TO MY PK-232, I FOUND I HAD SOME PROBLEMS USING
IT IN AMTOR. SINCE I LOVE TO MODIFY AND "FIX" RIGS, I GRABBED MY TEST
EQUIPMENT AND SET OUT TO FIND OUT WHY THERE WAS A LONG SWITCH-OVER DELAY TIME.
AFTER A FEW MINUTES, I FOUND OUT THAT THE RECIEVER WAS COMMING UP OK. IT WAS
THE MUTE CIRCUT THAT WAS SLOW. I FOUND TWO CAPACITORS THAT WERE RESPONSIBLE
FOR THE DELAY IN THE MUTE CIRCUT.
TO FIX THE PROBLEM, CHANGE OUT C74 AND C99 (BOTH ARE 4.7uf @ 50VDC) WITH .01uf
DISC CAPACITORS WITH A VOLTAGE RATING GREATER THAN 15VDC. THESE CAPACITORS ARE
ALSO FOUND IN THE HR-2510 AS WELL. THESE SEEM TO BE C139 AND C99 IN THE HR-2510
IF MY COPY IS RIGHT.
THESE CAPACITORS ARE LOCATED NEXT TO THE AUDIO OUTPUT IC (TDA1905) IN THE
RADIO. THIS I.C. IS LISTED AS IC2 IN THE HR-2600 AND IC103 IN THE HR-2510.
I ALSO FOUND THE S/RF METER TO BE VERY SLOW IN MY RIG. I FIXED THIS BY CHANGING
C302 ON THE CONTROL UNIT (LOCATED NEXT TO J304) TO A .01uf DISC CAPACITOR ALSO.
THIS CAPACITOR IS ALSO IN THE HR-2510.
AFTER THESE MODIFICATIONS, I HAD NO MORE PROBLEMS MAKING ANY CONNECTS IN ANY
MODE.
73'S AND ENJOY THE UNIDEN!
CRAIG/N7ETV @ WB6MQM
LAS VEGAS, NEVADA. 89121