Other spectrum analyzers would bypass the YIG preselector
when doing work above 3.
The S-Tec SA500 preselector
offers good autopilot automation and alerts.
The fluid transmission preselector
gear change was a feature of Daimler.
For example, option 067 for Anritsu's MS2830A provides preselector
bypass that supports 125-MHz wideband measurements to 43 GHz on an appropriately configured instrument.
The IF pan display shows all signals in the preselector
This general architecture places preselector
filters as the first element in the tuner chain, followed by low gain (typically 10-15 dB), high-intercept preamplifiers, followed by an upconverting mixer, amplification and filtering at the first IF (nominally 22.
Honeywell says the KFD 840 can replace the KAS altitude preselector
that goes with KFC-200/250 autopilots.
The new spectrum analyzer also features good channel flatness for all measurements due to a switched-filter preselector
The receiver's superheterodyne-based design with programmable (tunable) input preselector
and multiple IF bandwidths can support a wide range of telemetry and satellite applications.
The RF preselector
breaks the channel IF into manageable frequency bands for the A/Ds.