TEK nozzle for our GPS Logger 2/3 and the MicroVario. Angled design for installation in the vertical stabilizer.

Total Energy Compensation for the vario in the GPS Logger 2/3 and the MicroVario!

The TEK nozzle is the ideal addition to our GPS Logger 2/3 and the MicroVario. These feature a TEK connection on the vario and, together with the TEK nozzle, provide a vario experience similar to that of manned gliders.

Our TEK nozzle operates on the principle of the "Braunschweig nozzle." Human-carrying aviation uses this design almost exclusively today. Although the construction is more complex than the simple curved Nicks nozzle, it is unmatched in compensation and delivers perfect results even in model flying.

The nozzle is made entirely of stainless steel and hard-soldered.

The nozzle head is scaled 1:2. This sounds larger than it is, as the original nozzles are very small. The nozzle appears properly sized on models of virtually any size.

The 2.5 mm diameter tube in the angled version for installation in the vertical stabilizer is approximately 240 mm long and 40 mm high. In the original, this length is about 750 mm, so our nozzle has the correct length for a 1:3 scale model. For smaller models, the tube can be shortened slightly; for larger ones, it could be extended and reinforced with a carbon fiber tube.

The straight version for installation on the fuselage spine is approximately 120 mm long.

What exactly is TEK?

Simply put, TEK means eliminating "stick thermals" by taking the model’s speed into account. This is achieved by connecting a TEK nozzle to the vario sensor.

For slow models flying at a constant speed, the simple vario without TEK is often sufficient. Here, errors caused by controlled altitude changes are not as significant, and the vario already provides a good indication of thermals. The cleaner you fly and the smaller the speed changes, the better the vario works without a TEK nozzle.

However, with dynamic models or even with an imperfect flying style, there are always vario readings that do not indicate the model’s actual climb or descent, but only a controlled change in speed or altitude—the “stick thermal.” In reality, however, what matters when searching for thermals is only whether you are flying in rising, falling, or neutral air. Ideally, this should be independent of how the aircraft is currently moving.

This exact behavior is achieved by using a TEK nozzle on the variometer. This nozzle generates a speed-dependent vacuum and thus simulates a climb as speed increases, which compensates for the loss of altitude. So, when you accelerate, the altitude decreases, and a variometer without TEK would indicate a sink rate. The TEK nozzle compensates for this by indicating a climb rate corresponding to the increasing speed during acceleration. The conversion of altitude (potential energy) into speed (kinetic energy) is thus no longer incorrectly interpreted as a sink or climb by the TEK nozzle.

Ideally, with full compensation, the vario always displays the aircraft’s current rate of descent in completely calm air. Of course, this is not a constant value but depends on speed, lift, and other factors.

The connection between the TEK nozzle and the GPS Logger 2/3 or MicroVario is made using the separately available nozzle holder, Part No. 2785, and the tubing included with it.