UHF Repeaters

RF emission types are expressed as series of digits and letters defining the bandwidth, carrier type, modulating signal, type of information, type details and multiplexing. Some of these designators are optional but all have carrier and modulating signal type and purpose eg. F3E is Frequency modulated, single channel analog (no subcarriers etc.), telephony (voice). All will have a single numeral for the MODULATING SIGNAL and work backwards or forwards from there.

BANDWIDTH

If the emission is restricted to a certain bandwidth the mode designator is preceded by a bandwidth prefix eg. 10K5 means a bandwidth of 10.5kHz (not that this is ever used). eg 10K5F3E means FM single channel voice restricted to 10.5kHz bandwidth. The bandwidth is always 3 digits with "H" for hertz, "K" for kilohertz and "M" for Megahertz used as decimal points. To get as far as multiplexing, those before it (TYPE OF INFORMATION and INFORMATION DETAILS) are also quoted.

UNMODULATED CARRIER

A AM Double-sideband
H AM Single-sideband with full carrier
R AM Single-sideband with reduced or variable carrier
J AM Single-sideband with suppressed carrier
B AM Independent sideband (two sidebands containing different signals)
C AM Vestigial sideband
F Frequency modulation
G Phase modulation
D Combination of AM and FM or PM
P Sequence of pulses without modulation
K Pulse amplitude modulation
L Pulse width modulation
M Pulse position modulation
Q Sequence of pulses, phase or frequency modulation within each pulse
V Combination of pulse modulation methods
W Combination of any of the above
X None of the above

MODULATING SIGNAL

0 None
1 One digital channel, no subcarrier
2 One digital channel using a subcarrier
3 One analogue channel
7 More than one channel containing digital information
8 More than one channel containing analogue information
9 Combination of analogue and digital channels
X None of the above

TYPE OF INFORMATION

N None
A Aural telegraphy, intended to be decoded by ear, such as Morse code
B Electronic telegraphy, intended to be decoded by machine (Radioteletype and digital modes)
C Facsimile (Still images)
D Telemetry or Telecommand (Remote control or data collection)
E Telephony (voice or music intended to be listened to by a human)
F Video (television signals)
W Combination of any of the above
X None of the above

INFORMATION DETAILS

A Two-condition code, elements vary in quantity and duration
B Two-condition code, elements fixed in quantity and duration
C Two-condition code, elements fixed in quantity and duration, error-correction included
D Four-condition code, one condition per "signal element"
E Multi-condition code, one condition per "signal element"
F Multi-condition code, one character represented by one or more conditions
G Monophonic broadcast-quality sound
H Stereophonic or quadraphonic broadcast-quality sound
J Commercial-quality sound (non-broadcast)
K Commercial-quality sound-frequency inversion and-or "band-splitting" employed
L Commercial-quality sound, independent FM signals, such as pilot tones, used to control the demodulated signal
M Greyscale images or video
N Full-color images or video
W Combination of two or more of the above
X None of the above

MULTIPLEXING

N None used
C Code-division (excluding spread spectrum)
F Frequency-division
T Time-division
W Combination of Frequency-division and Time-division
X None of the above