HP 8920A, User Manual

Page: 255 / 658

255
Chapter 7, Configure Screen
Field Descriptions
Antenna In
This field is used to indicate losses or gains between the ANT IN port and the
device-under-test.
Enter a positive value to indicate a gain (such as an amplifier). The Spectrum
Analyzer’s
1
marker level (
Lvl
) measurement is automatically reduced by that
amount. The Spectrum Analyzer’s
Ref Level
is automatically decreased by the
same amount, so the trace position does not appear to change.
Enter a negative value to indicate a loss (such as cable loss). The Spectrum
Analyzer Marker’s Level (
Lvl
) measurement is automatically increased by that
amount. The Spectrum Analyzer’s
Ref Level
is automatically increased by the
same amount, so the trace position does not appear to change.
This field is only used when the
RF Level Offset
field is set to
On
.
See Also
RF Level Offset
field description, on page 265
1. Spectrum Analyzer is optional on some Test Set models.
Base Freq (User Defined)
The Base Frequency field sets the RF Generator reference for channel 0 (zero)
when the
RF Chan Std
field is set to
USER-DEF
, and the
RF Display
field is
set to
Chan
.
Channel frequencies are calculated using the following formula:
Channel N = Base Fre (N)(Channel Spacing)
The Base Frequency is calculated using the following formula:
Base Frequency = Channel 1 Frequency - Channel Spacing
For example, if your multi-channel radio’s lowest receive channel frequency is
870.030 MHz and the system channel spacing is 30 KHz, you would enter
870
MHz
in this field. You would also use the
Chan Space
and
(Gen)-(Anl)
fields
to tell the Test Set where other transmit and receive channel frequencies are in
relation to the base frequency, and whether or not the system is duplex.
Operating Considerations
The value of this field is only used if the
RF Display
field is set to
Chan
, and the
RF Chan Std
field is set to
USER-DEF
.