Sanyo VHR-770 Service Manual

Also see for VHR-770: Instruction manual

2-4. IF CIRCUIT ADJUSTMENTl In this model, the circuits of the TUNER, IF, and RF Note: The 3 in tuner dose not need any adjustments, becauseconverter have been made into one. Therefore, should one precise adjustments were down before shipment.circuit malfunction, the whole unit must be replaced.l The adjustments for the IF (RF AGC) circuit of the 3 in 1tuner are described below.2-4-1. TEST EQUIPMENT AND STANDARD REQUIREDMonitor TV2-4-2. LOCATION OF ADJUSTMENT POINTP36200EIRear Panel u h Y3 in 1 Tuner c >0 >c. >CP-1 PWBAssembly — c ><. >< >VR - c. >9c >“ e ‘73 in 1 Tuner Fig. 2-4-12-4-3. RF AGC ADJ.Measuring Point Measuring Equipment Adj. ConditionPictureof MonitorTV E-E modemonitor TVAdj. Location Adj. ValueVR (RF AGC) SIN is best point(on the 3 in 1 tuner)1.2.3.4.Connect the monitor TV to the VHFAJHF antenna outputterminal.Connect the VHF or UHF antenna to the VHFIUHF antennainput terminal.Receive the middle electrical field (70 dBp -90 dB~) of theVHF or UHF channel, and slowly turn the VR (RF AGC)from the point where snow-noise is present to the pointwhere it just disappears from the monitor TV.Confirm by monitor TV that there is no beat and saturation(S/N is best point) when receiving any TV channel.2-5. CHECKING THE RF CHANNELIf the TV and VCR are connected by an aerial output cable which has poor shielding characteristics, turn off the RF converter ofthe VCR and use the VCR with an AV cable. To turn the RF converter off, input “00” when setting the RF (when “RF” isdisplayed) during VCR pre-setting3. TEST POINTS FOR TAPE PATH ADJUSTMENTTest points TP182 (ENV) and TPI 83 (SW-P) for tape path adjustment are shown in figure below.For adjustment, refer to the separate volume “V95 I Mechanism Manual” (MM531 433) and “V95 I I Mechanism Manual” (MS531 500).P66300D TP163 TP182(SW-P) (ENV.)~/-ml mDF —VP-1 PWB Assembly Fig. 3-1–13–