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Davicom FMBM, Reference Manual, March 2015
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4.1 Local operation with front-panel display & buttons
4.1.1 Default display
If an appropriate high-level signal or antenna is connected to the unit and it is powered from a
12 Vdc power supply, the FMBM will automatically start displaying the receive frequency and
modulation level, alternating between the frequency drift and signal strength.
Display of
stereo presence/absence (ST/MONO) is permanently present on the bottom right of the LCD
screen.
Note that at all times when in this Default display mode, the UP and DOWN buttons control
the audio output level going to the headphones.
The 2 screens below show displays that would typically appear when tuned to a monophonic
station at 104.7 MHz. The display alternates between the 2 screens over an 8 second period.
The shaded fields would obviously vary depending on the frequency selected and on the
station’s signal parameters.
The fields indicate the selected receive
Freq
uency, the frequency
Dev
iation (FM Modulation),
the presence (or absence) of a
St
ereo (
Mono
) signal, the amount of carrier
F
requency
Drift
between the received carrier frequency and the FMBM’s highly-stable internal frequency
reference and finally, the Receive Signal Strength Indicator (
RSSI
). If the High-Level RF input
is selected,
RSSI
is replaced by
Lvl
, and the units become Volts instead of dBm.
If the AM band is selected, typical displays would be as shown below, where
Mod
is the AM
Modulation index.
When the signal source is set to MPX, these the following screen is displayed:
Freq 104.70 MHz
Dev 64kHz MONO
F Drift -0.25kHz
RSSI -59dBm MONO
Freq 800.0kHz
Mod 100% MONO
F Drift -.1kHz
RSSI -68dBm MONO
MPX IN
Dev 75kHz MONO
