TB 9-6625-106-24
11. Locked FM Mode On
a. Performance Check
(1) Press TI keys as listed in (a) through (f) below:
(a) System, Reset.
(b) Edit L1, 0, dBm.
(c) Edit F1, 5, GHz.
(d) Modulation, FM, Internal/External, select External.
(e) on/off, turn on External FM.
(f) OUTPUT to On.
(2) Allow measuring receiver to tune to TI carrier frequency, then measure FM
Deviation with PEAK + -/2 detector, and record FM Deviation reading as (N).
(3) On the TI press, on/off, turn off External FM.
(4) On the TI press, Internal/External, select Internal FM.
(5) On the TI press, Edit Deviation, 300, kHz.
(6) On the TI press, on/off, turn on Internal FM.
(7) Set measuring receiver to measure FM Deviation with PEAK + detector, no
filters, and record FM Deviation reading as (S+N).
(8) Calculate actual frequency deviation by using the following formula,
Sactual = (S+N)-N.
perform b below.
(10) On TI, turn off Internal FM, then repeat (1) (c) through (e) and (3) through (9)
above for the remaining frequency listed in table 11. If calculated frequency deviation is
not within limits listed in table 11, perform b below.
(11) Set TI outputs to minimum.
Table 11. Locked FM Mode On
Frequency Deviation
TI Carrier Frequency
(GHz)
Min (kHz)
Max (kHz)
5
270
330
20
270
330
b. Adjustments
(1) Interface the instrument controller to the TI by performing the initial setup
procedure listed in paragraph 7 a through c.
(2) Using a BNC tee, connect the function generator OUTPUT to FM/ )0 IN of the
TI and to the multimeter INPUT.