Agilent / Hewlett Packard 85685A
USED

RF Preselector
20 Hz - 2 GHz

More info

Add the 85685A RF preselector to the 8566B or 8568B general-purpose
spectrum analyzer, and you have a test receiver for specialized applications.
The RF preselector enhances these high-performance spectrum analyzers
with tracking filters and preamplifiers that cover the 20 Hz to 2 GHz range.
The spectrum analyzer/test receiver is sensitive to low-level signals
while providing overload protection from out-of-band signals.
The result, for tests in the presence of high-level interference,
is a measurement range 30 dB greater than that of the spectrum analyzer alone.
(The improvement is even greater in the presence of broadband pulse-interference.)