AM
& FM Broadcasting Standards
AM 520-1700KHz:
Frequency
Range: 525KHz(0.525MHz)-1700KHz(1.700MHz)
Channel
Frequencies: 531, 540, 549…627…774….1278KHz each station is 9KHz apart
(I.e. 9KHz Step)
Stereo
Signal: Compatible quadrature amplitude modulation (C-Quam) 25Hz
+/--0.1Hz with a deviation of between 3 to 5% of the quadrant channel
Frequency
Response: Within 2db (50Hz-7.5KHz)
THD: Not
exceeding 4% at 80% modulation (400Hz-5KHz)
Stereo Separation:
18 db minimum
FM 88-108.0000MHz:
Frequency
Range: 88.0000MHz to 108.0000MHz
Channel
Frequencies: 88.1000, 88.3000…91.7000, 91.9000, 101.1000,
101.3000…107.9000 each station is 2000KHz (0.2000MHz) apart
Deviation:
75KHz
Pre
Emphasis/De-Emphasis: 50 microseconds
Stereo
Channel Sub Carrier Frequency: 38KHz
Stereo
Channel Pilot Frequency: 19KHz
Notes:
Ancillary
communications services may be included in the main program channel, using the
following specifications
Sub
Carrier Frequency: 67KHz
Maximum
Deviation: 7.5KHz
Modulation: FM or
FSK*
Pre-emphasis: up to 150
microseconds (150us)
This
allows radio stations to use part of their own frequencies for car-to-studio
link ups etc and for information and other ‘feeds.’ Either Wide or Narrow FM can
be used [it will be NFM for two-way comms and WFM for any links].
The
Frequencies between 87.6000 and 88.0000 have been set aside for community
radio, tourist radio and other Low Power Narrowcasting Services.
FM radio
transmissions can only be received on scanners with a wide fm mode. This is
because normal two-way radio is in narrow, mono fm, wheras tv audio and fm
radio are in wide stereo fm.
Information
correct as at Tuesday, October 7, 2003.