Yaesu FT-857 Technical Supplement

Also see for FT-857 series: Manual Technical supplement Operation manual Brochure & specs Operating manual

Contents

Yaesu FT-857 Technical Supplement Manual pdf 13 page image

13Local Oscillator AdjustmentReference Frequency Adjustment1. Connect an RF millivoltmeter or an oscilloscope to pin2 of J5002 on the REF Unit.2. Confirm that the RF millivoltmeter reading is 115 mV(± 30 mV) rms or 320 mV (± 90mV) p-p.3. Connect the frequency counter to pin 2 of J5002 onthe REF Unit.4. Adjust the TC5001 for 67.875000 MHz (±10 Hz) onthe frequency counter.3rd Local Adjustment1. Connect an RF millivoltmeter or an oscilloscope toTP1037 on the MAIN Unit.2. Key the transceiver on CW mode, and adjust T1025for maximum indication on the RF millivoltmeter.3. Confirm that the indicated voltage is 100 mV (± 30mV) rms or 280 mV (± 80mV) p-p.PLL AdjustmentVCO VCV Adjustment1. Connect the DC voltmeter to TP1028 on the MAINUnit (or pin 6 of J2002 on the PLL Unit), and refer-ring to the table below, tune the transformer/inductoron the PLL Unit on each frequency listed. Then con-firm that the correct voltage is present, or adjust thelisted component for the required voltage.Tune to : Adjust / Confirm For13.895 MHz Adjust T2001 6.0 V ±0.1 V76.000 MHz Confirm At least 0.9 V32.995 MHz Adjust T2002 6.0 V ±0.1 V13.900 MHz Confirm At least 0.9 V55.995 MHz Adjust T2003 6.0 V ±0.1 V88.000 MHz Confirm At least 0.9 V163.995 MHz Adjust L2010 5.5 V ±0.5 V118.000 MHz Confirm At least 0.8 V469.995 MHz Adjust L2011 5.5 V ±0.5 V420.000 MHz Confirm At least 0.8 V1st Local Output Level1. Connect the RF millivoltmeter to TP1029 on theMAIN Unit (or pin 11 of J2002 on the PLL Unit), andset the transceiver to 28.000 MHz.2. Confirm that the RF level is at least 0 dBm or 200 mVrms.AlignmentMAIN Unit Alignment Points IREF Unit Alignment PointsTP1037T1025TP1028TP1029TC5001J5002 (pin 2)