1-79
Commercial fuse identification and a fuse cross-reference can be found in NEETS, Module 3,
Introduction to Circuit Protection, Control, and Measurement; and in Military Standard 1360A (MIL-
STD-1360A). These will assist you in selecting or identifying fuses.
Circuit breakers are too numerous to cover in this text. They are used in houses, vehicles, ships, and
airplanes. Military Standard 1498 (MIL-STD-1498) contains information to help you select or identify
circuit breakers.
Classification of Rf Emissions
The system of designating rf emissions is arranged according to modulation type, mode, and
supplementary characteristics. For example: A3B indicates amplitude modulation, telephony, two
independent sidebands, and a suppressed carrier. Table 1-23 will assist you in breaking down the
emission classification code.
Table 1-23.—Emission Types
Emission
Type
Modulation Types
Amplitude
A
Frequency
F
Pulse
P
Modulation (Transmission Mode)
None
0
Telegraphy (keyed r-f carrier)
1
Telegraphy (tone)
2
Telephony
3
Facsimile
4
Television
5
Four Channel Diplex Telegraphy
6
Multichannel Voice Frequency Telegraphy Complex
Forms
7
Supplemental Characteristics
Double Sideband
none
Single Sideband
-reduced carrier
A
-full carrier
H
-suppressed carrier
J
Two Independent Sidebands
-suppressed carrier
B
Vestigial Sideband Pulse
C
-amplitude modulated
D
-width modulated
E
-phase modulated
F
-code modulated
G
*Capital or lower case letter
**Commercial practice is to reduce carrier 20 dB, to provide sufficient
carrier for receiver afc lock-in, where afs receivers are used.
Note: a number preceding the emission designation indicates the
bandwidth in kilohertz.
