3D Connexion GNS 530(A) manual Volume, Squelch, COM Window and Tuning, Section COM

SECTION 2: COM

2.1 COMMUNICATING USING THE GNS 530

The GNS 530 features a digitally-tuned VHF COM radio that provides a seamless transition from communication to navigation, bringing the two most important functions in flying together in one panel-mounted unit. The GNS 530’s COM radio operates in the aviation voice band, from 118.000 to 136.975 MHz, in 25 kHz steps (default). For European operations, a COM radio configuration to allow for 8.33 kHz steps is also provided (Section 10.4, Setup Page: COM Configuration).

Volume

COM radio volume is adjusted using the COM Power/ Volume Knob. Turn the COM Power/Volume Knob clockwise to increase volume, or counterclockwise to decrease volume.

Squelch

The COM radio features an automatic squelch, providing maximum sensitivity to weaker signals while rejecting many localized noise sources. The pilot may wish to override this automatic squelch function when listening to a distant station or when setting the desired volume level. The COM Power/Volume Knob allows the pilot to disable the automatic squelch and keep the COM audio open continuously.

Overriding the automatic squelch:

1)Press the COM Power/Volume Knob momentarily.

2)Press the COM Power/Volume Knob again to return to automatic squelch operation.

SECTION 2

COM

COM Window and Tuning

Communication frequencies are selected with the tuning cursor in the standby COM frequency field (Figure 2-1), using the small and large left knobs to dial in the desired frequency. The standby frequency always appears below the active frequency. The active frequency is the frequency currently in use for transmit and receive operations.

‘RX’ Receive

Active COM Indication

Frequency Field

Standby COM

Frequency Field

Figure 2-1 ‘RX’ Receive Indication

A frequency may also be quickly selected from the database by simply highlighting the desired frequency on any of the main pages and pressing the ENT Key. This process is referred to as auto-tuning. Once a frequency is selected in the standby field, it may be transferred to the active frequency by pressing the COM Flip-flopKey.

While receiving a station, an ‘RX’ indication (Figure 2-1) appears in the upper right corner of the COM Window to the immediate right of ‘COM’. A ‘TX’ indication appears at this location when transmitting (Figure 2-2).

‘TX’ Transmit Indication

Figure 2-2 ‘TX’ Transmit Indication

190-00181-00 Rev. E GNS 530(A) Pilot’s Guide and Reference 2-1