Kenwood tk 880 parts
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Please check SM diagram).įinal result: improved TX modulation, close to Motorola quality.hi.Guest Order Status | Servicer/Dealer Login
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Why to decrease the microphone level using resistors and after again to boost the signal? The S/N ratio will be forever degraded.Īll dividers were removed in order to increase the original level of modulation: R512(680) removed R724(4K7) bypassed R725(15K) removed (resistors values found in my radio, not same with Service Manual. Immediately i saw some resistors between microphone connector and preamplifier stage. Good results but level of modulation was affected.
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Feedback R721(330K) resistors was replaced by 100K. The noise was decreased enough, but also high spectrum of audio modulation was affected. I tried to apply 1nF roll off capacitor in the feedback loop. IC preamplifier is located on Front Panel PCB. After investigation, IC711 microphone preamplifier was found with poor perfomances. Background noise was higher than my GP300 monitor. Poor signal / noise ratio of TX modulation - modificationĭuring testing I noticed a low signal to noise ratio for TX.
KENWOOD TK 880 PARTS MANUAL
"UHF F1" screen appear for short time, after that "Test Mode" can be accessed.Ĭheck the service manual for more details at Adjustment - page 45. Keep pressed key, in same time switch ON the radio. In order to activate the feature, R614 "zero ohm" resistor must to be deleted! This resistor is located on front panel PCB, near to CPU.Īfter that, the radio channels can be programmed directly by front panel keys.
KENWOOD TK 880 PARTS SOFTWARE
Front panel programming is possible only if "Self Programming Mode" option was previously selected by PC software (go to Edit / Option Feature and then upload to radio). Radio display when internal CPU is accessed by computer: Connect data cable and go to KPG-60D PC software at Edit / Channel Information. Channels programming procedure can be performed by PC software or using Front Panel keys. PC Software programming for TK-880: >KPG-60D>KPG-62D version 2.00> Programming Interface KPG-46 Schematic>Service Manual rev.