User`s guide

APOGEE ELECTRONICS
4
BIG BEN – User’s Guide
APOGEE ELECTRONICS
5
BIG BEN – User’s Guide
It’s Got a Mind of Its Own!
As Big Ben’s settings are modi-
ed, certain parameters and
values become unavailable for selec-
tion, while others seem to change all by
themselves! In fact, Big Ben intelligently
modies many settings according to the
conguration of the unit. For example,
when an external CLOCK SOURCE is
selected, SAMPLE RATE can’t be modi-
ed, as its value is determined from the
selected CLOCK SOURCE. As another
example, the VSO value may be selected
only when CLOCK SOURCE is set to
INTernal.
Keep in mind that before
modication of any Big Ben
setting, SETUP mode must
be enabled.
Navigating the Front Panel
1 2
1) Power Switch – Every aspect of Big Ben has been carefully
thought out – even the Power Switch! Three congurations, set with
internal jumpers, are available:
1) Big Ben is powered on in the expected manner, by pushing the
Power Switch;
2) Big Ben powers on automatically when AC input is applied, but
the Power Switch is still functional;
3) the Power Switch is completely disabled.
Please see the section on “Internal Adjustments” for instructions
on changing the Power Switch mode.
Note that the Power Switch LED indicates that Big Ben is receiv-
ing a proper AC input, and is in Standby mode. The LED goes
out when Big Ben is powered on.
2) Set-Up buttons and LED – These buttons are used to modify
all settings on Big Ben. In general, setting modication requires 4
steps: enabling Setup mode, choosing the parameter to be modied;
choosing the desired value and disabling Setup mode.
1) Enable Setup mode by simply pressing any of the SETUP but-
tons. The SETUP LED will illuminate and the value selected the
previous time SETUP mode was enabled will blink.
2) Press either the PREV or NEXT buttons until the current value of
the parameter to be modied is blinking.
3) Press either the UP or DOWN buttons until the desired value is
blinking.
4) If no buttons are pushed for 2 seconds, Setup mode is disabled
automatically, and the value which was blinking will now illumi-
nate solidly. All settings (except some VSO settings) are saved in
non-volatile memory, and will be recalled the next time Big Ben is
powered up.