19 lines
1.1 KiB
Plaintext
19 lines
1.1 KiB
Plaintext
PCS4000.2
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PCS-4000 MOTORBOATING MODIFICATION
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==========================================================================
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This modification cures a problem which appears only in some radios,
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particularly when the radio is very cold. It is variously described as,
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"You sound like you're underwater" or, "You break up on loud peaks," or
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garbled transmit audio.
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It is sometimes caused by RF getting into the radio. This is easily
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cured by connecting a .001 ufd. ceramic capacitor between pins 2 and 5 of IC402.
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In extreme cases, lowering the audio gain of IC402 by changing r472 to
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a lower value may be of benefit. In older models, this original resistor
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is 100 k-ohms; in newer radios it is 51 k-ohms. Try lowering it to 47k or 39k.
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To get at the bottom of this PC board, remove radio top cover (4 screws;
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note that right front screw must be a short screw), unsolder a red wire from
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a post on the front left of the board, unplug the coax from J404 and the 6
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wire plug from J401. Remove 7 screws and flip board over to the right.
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Reverse this procedure to re-assemble.
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