TB 9-6625-2273-40
NOTE
If problems are encountered in meeting requirements of (3)
below, (caused by dc blocking capacitor) use multiples of 1 kHz
(i.e., 2, 3, 4 kHz, etc.) until desired indication is obtained.
(3) Enter 1 kHz on TI DATA keyboard and adjust spectrum analyzer No. 1 controls
as necessary to establish an amplitude reference point of TI output signal which will permit
a signal attenuated by 35 dB to be measured.
(4) Adjust spectrum analyzer No 1. controls as necessary to view TI output signal 2d
through 5th harmonics. The TI output signal harmonic amplitudes (as indicated on the
spectrum analyzer No. 1 display) will be as specified in (a) and (b) below:
(a) The 2d harmonic amplitude will be 30 dB below reference established in
(3) above; if not, perform b below.
(b) The 3d, 4th, and 5th harmonic amplitudes will be 35 dB below reference
established in (3) above; if not, perform b below.
NOTE
It is important that TI keyboard DATA entries be followed
exactly as listed in steps (5) and (8) below in order to evaluate
the worst case harmonics at the TI filter switching frequencies.
(5) Press TI OUTPUT HEAD ON/OFF pushbutton (turn output OFF) and
disconnect spectrum analyzer No. 1 from TI.
(6) Connect spectrum analyzer No. 2 INPUT 50
to TI output using dc blocking
capacitor. Press TI OUTPUT HEAD ON/OFF pushbutton (turn output ON).
(7) Repeat (3) and (4) above for TI DATA keyboard entries listed in table 4. If
spectrum analyzer No. 2 does not indicate as specified, perform b below.
Table 4. Harmonic Content
Test instrument output
Spectrum analyzer No.2 indications
(below reference)
d harmonic
3d, 4th, 5th harmonic
2
10
kHz
> 30 dB
> 35 dB
25
kHz
> 30 dB
> 35 dB
49.999 kHz
> 30 dB
> 35 dB
50
kHz
> 30 dB
> 35 dB
100
kHz
> 30 dB
> 35 dB
500
kHz
> 30 dB
> 35 dB
1
MHz
> 30 dB
> 35 dB
10
MHz
> 30 dB
> 35 dB
140
MHz
> 30 dB
> 35 dB
160
MHz
> 30 dB
> 35 dB
290
MHz
> 30 dB
> 35 dB
310
MHz
> 30 dB
> 35 dB
500
MHz
> 30 dB
> 35 dB
7