www.fmuser.org
www.fmuser.org
8
Wattmeter
MODEL 43
0
～
1KW
Bird
50
Ω
Attenuator
DLA-1000W
VSWR
＜
1.20
DC-1GHz
BED
Table 4-1 Test instrument for ZHC518A-50/100/200/300W TV transmitter
5. Test and Maintenance
As a high performance and high index TV transmitter, ZHC518A-50/100/200/300W TV
transmitter’s relevant specifications such as distortion; audio frequency response, video frequency
response, and signal to noise ratio etc. totally meet the national relevant standards and industry
standards of TV transmitter, and some of their technical specifications is much higher than the
national standards and industry standards.
5.1 Performance Test
To ZHC515A family TV transmitter, video index and RF index need to be tested.
a. Connect transmitter and test Instrument with cable according Figure 5-1.
b. Adjust the output level of modulation; make the output peak power, which is read from
Wattmeter, to be rating power.
c. Test the video index according
§
2.1.
5.2 Maintenance
It needs to use new fans instead of the old ones which have worked more than 15000 hours. If
Figure 5-1 connecting for video index test
ZHC518A TV
transmitter
Wattmeter
Attenuator
RF
RF
RF
Video
Video
TV signal
generator
Video
measurement
TV monitor
receiver
