Tuning a High Sierra Motorized Antenna is really very simple and the concept goes back to the 1950's.  Here's a non-technical discussion of how the antenna is tuned.  It's a little long and wordy but honestly, the tuning takes just seconds to tune a motorized High Sierra Antenna. 

As you know, the HS-1800/Pro and Sidekick have a reasonably high Q (efficient) loading coil inside of an aluminum tube.  That coil is moved up and down (in and out of the tube) by our small, well designed Black Hawk Motor.  The Black Hawk Motor turns a long stainless steel screw (called a jack screw) that moves the coil up and down.  The movement of the motor is controlled by one of our controllers.  The controllers are supplied with the antenna.  

For the purpose of this discussion, think of the controller as simply a switch that will energize the Black Hawk Motor to turn on going one direction or the reverse.  The switch therefore raises and lowers the coil.  The switch is our custom rocker switch with up/down arrows.

The electrical connection between the controller and the Black Hawk Motor inside the aluminum tube is simply two wires.  The polarity is reversed to change the direction of the motor.  In other words, when the switch is rocked up, the coil can go up.  When the switch is rocked down, the coil can go down. Inside the aluminum tube are special stops that limit the travel of the coil.  The coil can be held against the stop for over an hour with no heating of the Black Hawk Motor.

If you think in terms of wavelength or bands instead of frequency, this explanation is a little easier.  With the antenna fully retracted, it is shorter and therefore, on the shortest wavelength (like 10 meters).  With the antenna fully extended, it is on the longest wavelength (like 80 meters). 

So, if you were going to tune the antenna to say 20 meters and the antenna was fully retracted, you would need to raise the coil (to go from 10 to 20 meters). Typically, that takes just a few seconds.  The way I do that is to change the mode from SSB to AM on the transceiver.  Then I press the microphone switch so the transceiver is transmitting.  I then rock the swith up to raise the coil.  I watch the built-in SWR meter on the transceiver.  When I see the SWR dip down, I toggle the switch for the lowest SWR.  Anything less than 2:1 is good.  There is no increase in efficiency or performance with a lower SWR.  If the transceiver that I am using has no SWR meter, I simply use the built-in power meter and tune for maximum power. 

Here's another example, if the antenna were on 20 meters and I wanted to use 15 meters, I know that I need to lower the coil (make it shorter for a shorter wavelength).  I again transmit in AM and watch the built-in SWR meter.  When the SWR dips down in just a very few seconds, the antenna is tune and I am ready to go.

If I wanted to go to 80 meters, I would raise the coil so that it was fully extended.  I would then transmit on AM and press the switch to lower the coil.  Again I would watch the built-in SWR meter and tune for the lowest SWR.  

So that's how it is done.  It is not complicated and it does not any automatic device to do the tuning.  The antenna can be tuned in just seconds. 

Another advantage of the High Sierra design that has been copies by many, is that the coil retracts into the aluminum tube.  The advantage is that part of the coil that is inside the tube has no current running through it.  All of that adds to the efficiency of the design.  Changing length makes the antenna more efficient.