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
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
Modulation (Transmission Mode)
Telegraphy (keyed r-f carrier)
Four Channel Diplex Telegraphy
Multichannel Voice Frequency Telegraphy Complex
Two Independent Sidebands
Vestigial Sideband Pulse
*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.