— 17 —
output. Considering that today’s broadcasters utilize heavy
audio processing, the ‘crest factor’ (average-to-peak ratio)
will be very low, meaning that the average and peak levels
will be close to the same figure in both cases.
PI, Call Letters and Time
(Menu Screen 10)
PI:
is the station’s four-character, hexadecimal identifier,
the station’s “digital address.”
In North America the PI code is numerically derived from
station call letters. Proper ‘reverse-decoded’ call letters for
the PI code will display in the
CL:
field if the station ad-
heres to the RBDS standard.
In some instances, North American PI codes derived from
call letters will conflict with use of the RDS TMC (Traffic
Message Channel) function. In those cases stations may
adopt a ‘bogus’ PI code
that will back-calculate
to incorrect call letters
or a display of
????
. If
incorrect call letters hap-
pen to be the same as another station’s legitimate assign-
ment, the two stations must necessarily be in widely-
separated coverage areas to avoid RDS housekeeping con-
flicts.
Another RDS utility sets the listener’s radio clock to the cur-
rent local time. This is a double-edge sword, however, if the
broadcaster’s primary coverage area incorporates two time
zones. This could lead to confusion and alienate listeners.
For this and other reasons, many broadcasters choose
not
to
implement this RDS timekeeping utility.
The lower line Menu Screen 10 scrolls the RDS Clock/Time
field, if transmitted. This will include the date, the current
time in 24-hour notation, and the offset from UTC (Univer-
sal Coordinated Time). It may take a short while to receive
the RDS
Time:
‘packet,’ as it is not sent continuously.
— 18 —
PTY and PTYN
(Menu Screen 11)
The RDS PTY (Program
TYpe) function identifies
‘programming type’ (or
‘format’ in the US) from
a list of some thirty fixed
categories. Some consumer radios can be programmed to
search automatically for available programming based on
the PTY sets of identifiers. The upper line on this screen
identifies the decoded PTY by name from the appropriate
list.
The PTY field is one important difference between the US
RBDS and European RDS standards. The proper PTY list is
selected automatically when the INOmini 673
Region:
is
set in one of the ‘hidden’ menus with explanations begin-
ning on Page 23.
PTYN is an optional 8-character identifier used to further
define the programming type or format. It is not used by
the receiver to search for specific programming, but once
the receiver is tuned to the station PTYN can further detail
the program content and present it on the faceplate of some
radios.
PS and RadioText
(Menu Screen 12)
The upper line of this menu shows the station’s 8-character
PS:
, or Program Service Name. This can be a
static
-PS mes-
sage, like the station’s call letters:
WREN-FM
, or a familiar
‘street name’ such as
LIVE-95
.
Most stations now prac-
tice
dynamic
-PS messag-
ing, actually transmitting
a different 8-character
block at quick intervals
to create a scrolling display on the radio faceplate. This can
convey song title and artist information, program promo-
tions or even advertising.
RT:
(RadioText) is a 64-character message sent as a com-
plete data block. It is displayed on consumer receivers that
have a
TEXT
or
INFO
button. The INOmini 673 automatical-
ly scrolls the
RT:
message to display all 64 characters on
the front-panel LCD screen.
