Filter
Top Products
5-10
Internal FM
Specification
Deviation range
0 to 100 kHz.
Resolution 3 digits or 1 Hz.
Accuracy ±5% at 1 kHz modulation rate.
Bandwidth (1 dB) DC to 100 kHz (DC coupled),
10 Hz to 100 kHz (AC coupled),
20 Hz to 100 kHz (AC coupled with ALC).
Carrier frequency offset Less than 1% of the set frequency deviation when DC coupled.
Distortion Less than 3% at 1 kHz rate for deviations up to 100 kHz.
Typically <0.5% at 1 kHz rate for deviations up to 10 kHz.
FSK
2 level or 4 level FSK.
Note that 4 FSK is not available with Option 11 Fast Pulse fitted.
Test equipment
Description Minimum specification Example
Modulation meter
FM accuracy ±1% at 1 kHz modulation frequency
IFR 2305 with
distortion option
DVM DC voltage measurement Solartron 7150+
50 Ω load
(termination)
1 W, 50 Ω nominal impedance, DC to 2.4 GHz
Lucas Weinschel
M1404N
Audio analyzer Capable of measuring THD of 0.01% from 100 Hz
to 20 kHz
Rohde &
Schwarz UPA3
Function
generator
DC to 100 kHz sine, ±0.6 dB flatness
Agilent 3325B
FM deviation and distortion
Test procedure
UUT
2305
Modulation meter
C2564
RF INPUT
RF OUT
Fig. 5-7 Internal modulation and modulation distortion test set-up