Onkyo T-9090 II FM Tuner Alignment



Optimum alignment of the Onkyo T-9090 II can be accomplished with minimal equipment. A digital multimeter, hexagonal and planar blade plastic alignment tools, and a stable weak signal source will suffice. (Warning) attempts to align the hexagonal ferrite cores with a metal screwdriver will crack the ferrite! Some of the smaller ferrite cores can be adjusted with a standard screwdriver, providing the alignment is proceeded with care.

Mark initial inductor/potentiometer positions with a black text marker. This will serve as a reference point.

RF Front-head Adjustment

Step 1: tune to 108.0 MHz. Using a digital DC multimeter, adjust TC005 for 24.0 volts on TP6 (+/- 0.2 volts maximum deviation).
Step 2: tune to 87.50 MHz. Using a digital DC multimeter, adjust L006 for 4.0 volts on TP6 (+/- 0.1 volts maximum deviation).
Step 3: tune to 108.0 MHz. Using a digital DC multimeter, adjust TC001, TC002, TC003, TC004 for maximum DC voltage on TP6 (maximum sensitivity).
Step 4: tune to 87.5 MHz. Using a digital DC multimeter, adjust L001, L002, L003, L004 for maximum DC voltage on TP6 (maximum sensitivity).
All steps 1-4 with RF mode (DX), and IF mode (super narrow). TP7C may be more suitable for some multimeters.
Repeat steps 1-4 until no further improvement is obtained.

IF level Adjustment of wide and narrow

1. Tune to 99.0 MHz. With wide IF selected, adjust L105 on TP7A for maximum signal.

IF level adjustment of super narrow

1. Tune to 99.0 MHz. With super narrow IF selected, adjust L152 on TP7C for maximum signal.

Muting adjustment of wide and narrow

Step 1: Tune to 99.0 MHz. With wide IF selected, adjust L107 on TP1A for 0 volts.
Step 2: Tune to 99.0 MHz. With wide IF selected, adjust R101 on TP2A for desired muting level.

Muting adjustment of super narrow

Step 1: Tune to 99.0 MHz. With super narrow IF selected, adjust L159 on TP1B for 0 volts.
Step 2: Tune to 99.0 MHz. With super narrow selected, adjust R190 on TP2B for desired muting level.

PLL detector adjustment

1. Tune to 99.0 MHz. With RF DX and wide IF selected, adjust L203 on TP-9 for 0 (+/-0.1) volts on TP-9.

Signal strength meter level adjustment (dB)

R804, R802, R184, R189 (optional adjustment).

VCO

1. Tune to 99.0 MHz. Connected a frequency counter to TP4. Adjust R301 for 76 KHz +/- 76 Hz (Use the high impedance probe).

Adjustment Procedures.

Inductor Coils & Test Points.

T. Emslie 2006.