C3061 (F),C3100 (G),C3049 (H): Main-Board; Y-Amplifier Bandwidth Check; C2004, C2005, C2010, C2011: Attenuator Compensation Ch I; C2060, C2061, C2066, C2067: Attenuator Compensation Ch Ii - Hameg HM1004 Service Manual

13) R9001 (A),C9001 (B),R9004 (C),C9014 (D),R9010 (E): Y-Final Amplifier.

C3061 (F),C3100 (G),C3049 (H): Main-Board

Connect a 1MHz square wave signal of 25mVpp via 50Ω cable and 50Ω throughtermination
to input CH I.
Set time base to 0.05µs/div. for overshoot and 0.2µs/div. for adjustments of the top.
Locate and identify the adjustment points R9001 (13A), C9001 (13B), R9004 (13C), C9014 (13D),
R9010 (13E) on YF-Board and C3061 (13F), C3100 (13G) on Main-Board.
Adjust all adjustment points for flat top, fast leading edge (minimum risetime) and minimum overshoot.
Please note: The adjustment points A and B are most important for the overshoot and bandwidth.
C, D, E, F and G influence the top.
Repeat the adjustment of each adjustment point until optimum is obtained.
Check channel II under the same conditions and adjust C3049 (13H) for same bandwidth like CH I.

14) Y-Amplifier Bandwidth Check.

Connect a 40mVpp/50kHz sinewave signal from a constant amplitude generator via a
50Ω throughtermination to the input of channel I.
Adjust the generator amplitude for 8 div. display height on the screen.
Increase the generator frequency until the signal height is 5.6 div. ( -3dB).
Repeat the adjustment under item 13), if the frequency reading on the generator shows a value less
than 100MHz.(150MHz for HM1505).
Repeat the same procedure under channel II operating conditions.

15) C2004, C2005, C2010, C2011: Attenuator Compensation CH I.

Locate and identify trimmers C2004(15C), C2005(15D), C2010(15A) and C2011(15B) in CH I
section of the AT-Board.
Set time base switch to 0.2ms/div.
Set amplitude calibrator to 1kHz, connect a 50Ω cable at the generator output and via
a 2:1 pre-attenuator to input of CH I.
Set calibrator output voltage to 80mVpp (40mVpp at the 2:1 pre-attenuator output).
Check for 8 divisions signal height (5mV/div. attenuator setting).
Adjust trimmer in pre-attenuator for flat square wave top. This adjustment must not be
changed during the following procedure.
Adjust compensation as listed in the table below:
Scope
Input
250mVpp
2.5Vpp

16) C2060, C2061, C2066, C2067: Attenuator Compensation CH II.

Press CH II pushbutton to switch channel II on.
Press CH I pushbutton to switch channel I off.
Locate and identify trimmers C2060(16C), C2061(16D), C2066(16A), C2067(16B) in CH II
section of the AT-Board. Set time base switch to 0.2ms/div.
Set amplitude calibrator to 1kHz, connect a 50Ω cable to the generator output and, via
a 2:1 pre-attenuator to input of CH I.
Set calibrator output voltage to 80mVpp (40mVpp at the 2:1 pre-attenuator output).
Check for 8 divisions signal height (5mV/div. attenuator setting).
Adjust trimmer in pre-attenuator for flat square wave top. This adjustment must not be
changed during the following procedure.
Adjust compensation as listed in the table below:
Scope
Input
250mVpp
2.5Vpp
Subject to change without notice
Input Adjustment
Atten.
50mV/div 15A (C2010) flat top
15B (C2011) leading edge
0.5V/div 15C (C2004) flat top
15D (C2005) leading edge
Input Adjustment
Atten.
50mV/div 16A (C2066) flat top
16B (C2067) leading edge
0.5V/div 16C (C2060) flat top
16D (C2061) leading edge
CH I
CH II
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