What altitude do you put in the altitude
preselector? The safe answer is to only select the altitude for which you're cleared.
Bearing in mind that the wonder of the world in the primary school classroom at the time was the
preselector gearbox and cars did not even have seat belts, it was little wonder that I treated this view with derision and could not suppress a smile.
The
preselector typically is based on YIG technology and has a bandwidth of about 50 MHz--significantly less than the IF.
Solidly, built and durable they featured torsion-bar front suspension, hydro-mechanical brakes and a
preselector transmission option.
This stage is also known as a
preselector stage (the front end of the receiver).
Speaking of autopilots, we're fond of the S-Tec SA-500 altitude
preselector and alerter.
Although technically speaking the DB18 uses manual transmission, the car actually has a four-speed Wilson
Preselector gearbox in tandem with the Daimler Fluid Flywheel.
He says: "These cars were very popular with the ladies because of the
preselector gearbox which made it easy to drive.
This seven-channel RF
preselector filter provides seven selectable RF filter channels over a wide frequency range with ultimate rejections out to 18 GHz.
A Tek article (5) considers 35 to 40 MHz as the practical YIG
preselector bandwidth.