**TB 9-6625-127-24**

**dt. **Set TI as outlined in (1) through (9) below:

(1) **TRIG MODE **to **NORM**.

(2) **CTRL **mode to **AM**.

(4) **COMPL OUTPUT **to off.

(5) **DISABLE OUTPUT **to off.

(6) **FRQ **to **15 kHz**.

(7) **DTY **to **50%**.

(8) **AMP **to **16 V**.

(9) **OFS **to **0 V**.

**du. **Set function generator for a 2 kHz sine wave, 4.5 V amplitude, 0 V offset output.
**dv. **Configure spectrum analyzer to display 15 kHz carrier, sidebands, sideband

harmonics and 2 kHz modulation signal as shown in figure 4.
**dw. **Adjust spectrum analyzer gain for a 0 dB carrier level.

**dx. **Adjust function generator amplitude until modulation sidebands are 7 dB down from
carrier.

**dy. **Set A1R413 (fig. 1) to middle position.
**dz. **Adjust A1R414 (fig. 1) to minimize the level of 2 kHz modulation signal and its
**ea. **Set TI **AMP **to **1 V **and adjust spectrum analyzer so carrier level is 0 dB.

**eb. **Readjust A1R414 (fig. 1) to minimize 2 kHz modulation signal level and its 4 kHz
harmonic. (R)

**ec. **Repeat steps **dt **through **eb **above for best compromise at both TI **AMP **levels.

**ed. **Verify at both TI **AMP **levels that all harmonics of sidebands are at least 42 dB
lower than sidebands (49 dB lower than carrier). Remember to adjust spectrum analyzer

each time TI **AMP **level is changed, so carrier level is 0 dB.

**ee. **Repeat steps as listed in (1) through (5) below:

**cr **through **cu**

(1)

**cw**

(2)

**da **through **dc**

(3)

**df **and **dg**

(4)

**ed**

(5)

**21**