Kenwood TM-2550A Service Manual

Also see for TM-2530A: Instruction manual Instruction manual Instruction manual Instruction manual Instruction manual

Li2 CFY455SCIRCUIT DESECRIPTIONTM-2550A/E,2530AInput/Output characteristics Principle of operation of window comparatorof L12.8R CENTER DATECTOR9 (X59-1030-10) +eeoEt: 4.1V—0 (4.06V) |“ 1 6 sei - 7 1 ,Rt 1 ae etCt 5 101 (2/2) Et E2 et &1 £2y OR? ei=4.1Vi0e 1C1(2/2)q WrC4 01Qi b> ]}~ C4172) oe beg4iv_ 23 2g = | J.E23 -eq 3 @ : Set voltage at time when .82V Ns detuning from 3kHz. .[ ST (About 0.04V) Ei e2 et—_10 ;4ry= a¢ Center detectionod Set to “H” when signals received from |outside is within about + 3kHz. BD : Center stop signalSet to “L" when in SOL OPEN mode at center.z [CONT-14-BD]e 8R nL +4 SOL CONTROL3 9 {(X89- 1040-10)§ at |cunemmens aQ6 tusned on when in SQL. OPEN 4 turned on whenmode while searching vacant channels. in SQL OPEN modeLis = R1 R5 at center.aNOISEFILTER ‘|as a7 | D5 10 RG 1 Q3 turned onNOISE when in SQL :P FM DET 5 turned on when signal| iF AM KY AMP. H + Set to “H" when in OPEN mode. received from outside is© ° SQL OPEN mode. at center.Le ———- a 5 ” Set to about OV when in: Ic. SQL CLOSE or TX mode.[ ” . omeatiien.® - ;I NOISE DET.| awit th. Q39 is cut off for muting when in SQL| 6 x CLOSE, TX, or ALERT mode. 1| ° ox| , ” o | C103 «C104 At 1 A seF PA| c100 3 + im “‘ 7| AF VR10 —a1Q2 turned on when searching Q1 is turned on and O9vacant channels to change is cut off for muting when °Q3 Q2| >” from SQL to VR3. in TX or ALERT mode. Set to “L" normally.mode. Set to “H’ when searchingvacant channels in DCL04 RS OPERATION mode.> a Jz |Q3 turned off when RT 2 T Sassearching vacant —edchannels. ZL°7 7 ALERT, VACANT CH. (X§9- 1020-10) |Fig. 2 Center datector, Alert, Vacant CH, SQL control circuit