Furuno FM-8800 Service Manual

6.2 Measurement
6-8
6.2.5 Frequency deviation for a radiotelephone
Connect FM Liner Detector as below. Connect AF OSC (AF Oscillator) and an
appropriate switch as a substitution to PTT switch.
Fig. 6.2.5 Measurement of Frequency Deviation
Procedure
1. Set up the frequency for AF OSC to 1 kHz. Modulation frequency: 1 kHz.
2. Turn on PTT switch.
3. Adjust the output level of AF OSC (Adjust the modulation level.) so that it may be set
up to Frequency Deviation: 3.5 kHz.
4. Measure the Frequency Deviation when the modulation level is increased +20 dB
from the above-mentioned AF OSC level.
Frequency Deviation is regulated to be within 5 kHz.
NOTE:
Modulation Index (m) =
(kHz)frequency Modulation
(kHz)deviation Frequency
50 ohm
Dummy
50 ohm ATT
(20dB)
FM-8800S
FM-8800D
ANT
HANDSET
CH70 ANT
FM Liner
Detector
AF OSC
PTT SW
600 ohm
1-2
3-4
Pick-up

Furuno FM-8800 Specifications

General

Brand	Furuno
Model	FM-8800
Category	Cordless Telephone
Language	English