Translated by R.Whitehead 10-3-2014 (my best effort – accuracy is not guaranteed)
12 of 38
6.7. Vario
The GPS-Loggger 2 has a high resolution Vario sensor with a TEK connection.
TEK
= Total Energy Compensation
TEK Düse
= nozzle on the aircraft fitted with a hose connection to the Vario, usually mounted in front
of the vertical tail.
6.7. 1. TEK Connector
TEK put simply means the suppression of “stick thermals” by considering the motion of the
model. This is achieved by connecting a nozzle (pitot tube) to the TEK connector of the
Vario.
For slower models flying at a constant speed the simple Vario without the TEK nozzle is
often sufficient. Here the error due to control inputs is not so great and the thermals can
clearly be seen with the Vario. The cleaner and slower you are flying the better the Vario
does without the TEK nozzle.
With dynamic models or even with less than perfect flying style the Vario is always
indicating, which is not showing the true rise and fall of the model but only a controlled speed
or altitude change i.e. the “stick thermals”. We are indeed interested in the thermals, but only
whether you are flying in rising, neutral, or falling air mass. If possible regardless of how the
aircraft just moved.
Exactly this behaviour is achieved by using a TEK nozzle with the Variometer. This nozzle
produces a motion dependent pressure drop simultaneous with increasing speed, a rise
which compensates for the height loss. So yiou press on and the Vario without TEK would
indicate sinking. The TEK nozzle compensates for this by indicating the increasing speed
available for climbing. The conversion of height (potential energy) into velocity (kinetic
energy) is therefore with the TEK nozzle no longer incorrectly displayed as sinking or
climbing.
Ideally, with full compensation, it will always show the current sink rate of the aircraft in quiet
air. This of course is not a constant value but depends on the speed, buoyancy, and other
factors.
The GPS-Logger 2 has a TEK port on the top. The hose of the TEK nozzle is simply plugged
into this. In principle all types of TEK nozzle can be used, including the well known Nicks
nozzle or the Brunswick nozzle. The nozzles differ in sensitivity to sliding and angle of attack
and the possible compensation factor. Soon we will have on offer a nozzle of the Brunswick
type. This is very insensitive to the angle of attack and allows complete compensation. In
addition the compensation can easily be adapted.
6.7. 2. Vario Output via Telemetry
The tone of the Vario is made (with the exception of the old Jeti without EX) in each case in
the telemetry transmitter or telemetry box. For this purpose the Vario value transmitted from
then GPS-Logger 2 is in m/s. Not all transmitters have settings to adjust the sound, to hide
certain areas or adjust the sensitivity of the acoustic output.
Therefore, the GPS-Logger 2 has the following settings that affect the transmission of the
variable values with all telemetries: