Figure 5
Figure 6
Figure 7
Forward Compensation
Forward Path external and probe compensation values are
also programmed in the testpoint compensation screen
(Figure 7).
Saving Test Point Compensation Files
Test point screens can now be saved by sequentially pressing
the FUNCTION (green) key and #2 key. Common test point
configurations can be saved with a descriptive name of the
node type, amplifier type or location. The files can then be
recalled and applied to the appropriate device under test.
NEW FEATURES ON THE SDA SERIES METERS
SDA-5000 (with OPT. 1) CW Loopback
CW Loopback allows the user to generate and receive a single
CW frequency using one unit (Figure 8). Connect the output
(opt. port) of the SDA-5000 to the input of the device under
test (DUT), and connect the SDA receiver input to the output
of the DUT. The CW Loopback measurement can be accessed
by selecting the LOOPBACK icon from under the RF Measure
Tab in the NAVIGATOR (Figure 9).
•
This feature is ideal for simple troubleshooting of a field
active/passive device to determine gain, loss or continu-
ity. Any frequency from 5-1000 MHz can be selected, and
the output is adjustable from +20 to +50 dBmV.
Figure 4
SDA-5000 Test Point Compensation / Reverse
Level Configuration
A new graphical user interface has been added to simplify
programming of the forward and reverse test point compen-
sation. Test point compensation can be accessed by either
sequentially pressing the FUNCTION (green) and 7 keys, or
selecting the TEST POINT icon in the NAVIGATOR menu.
Reverse Compensation and Reverse Sweep / Telemetry Levels
Reverse test point compensation values and reverse teleme-
try and sweep level values are now programmed from the
same screen (Figure 5). Losses internal or external to the
device under test may be entered.
The reverse telemetry level and sweep levels are also entered
on the reverse compensation screen. When adjusting the lev-
els please note the following program sequence:
•
Entering the telemetry value will change the sweep value
to same level. That is, the sweep value will always "track"
the telemetry value unless the sweep value is changed
independently. This feature was implemented since both
telemetry values and sweep values are the same under
most circumstances.
•
If the device being tested requires different values for
telemetry and sweep, simply enter the desired telemetry
value first, followed by the sweep value.
•
Always remember to enter the desired level that you
want injected to the device under test. The user will be
warned if the desired input level is not achievable given
the test point compensation values (transmitter output
is adjustable from +20 to +50 dBmV).
Reverse Compensation Information Screen
The reverse compensation information screen provides addi-
tional detail to the reverse TP set-up screen (Figure 6).
Information includes the transmitted output level from the
SDA-5000, and the actual level at the device under test.
•
Please note the REVERSE TELEMETRY FREQUENCY
header at the top of Figure 6. This reference frequency
that appears in the header is actually programmed in the
3ST, 3HRV, SDA-5500 or SDA-5510, but is displayed after
you perform the first reverse sweep. Therefore, the
default frequency will always be 40 MHz until you per-
form a reverse sweep, and then this frequency will
change depending on what frequency was programmed
in the headend unit.
