Learn to tune COM1/2 and NAV1/2 frequencies on a Garmin G1000, swap standby to active, select audio or CDI, and fix common mistakes.
On a Garmin G1000, select COM1/COM2 or NAV1/NAV2 with the appropriate dual tuning knob, turn the large outer knob for MHz and the small inner knob for fractional digits, then press the frequency-transfer key to swap the standby frequency into active. COM and NAV use separate controls.
For both Aviation & Real-World Flying procedures and faithful simulator implementations, the key distinction is between tuning a standby frequency and making it active. Turning the knob alone does not change the active frequency.
How do I enter and activate a G1000 frequency?
Enter the required frequency in the selected standby field, then transfer it to active with the adjacent swap key.
- Power the avionics. Confirm that the G1000 and the aircraft’s avionics or radio bus are on and that the frequency fields are displayed normally.
- Select COM1, COM2, NAV1 or NAV2. On a standard G1000 bezel, press the small COM frequency knob to move the tuning box between COM1 and COM2. Press the corresponding NAV frequency knob to choose NAV1 or NAV2. The selected standby field is normally marked by a cyan box.
- Tune the standby frequency. Turn the large outer knob to change the MHz digits and the small inner knob to change the fractional or channel digits. Channel spacing and the number of displayed digits depend on the radio installation.
- Check the complete frequency. Make sure it has been entered in the intended radio’s standby field. No
ENTkey is required. - Press the transfer key. The active and standby frequencies exchange places. The former active frequency remains available in standby.
- Select how the radio will be used. For COM, use the audio panel to select the transmitter and receivers. For NAV, select the appropriate VOR/LOC source on the CDI or HSI.
| Radio | What tuning does | Separate action still required |
|---|---|---|
| COM1 or COM2 | Places the voice frequency in the selected receiver | Select the correct microphone and receiver on the audio panel |
| NAV1 or NAV2 | Tunes a VOR, localiser or compatible navigation facility | Select NAV/VLOC rather than GPS and identify the facility |
Why does the COM frequency show correctly but remain silent?
A correctly displayed COM frequency can remain silent if it is still in standby, the wrong receiver is selected, or the station is out of range.
- Confirm the frequency appears in the active COM1 or COM2 field.
- Select that receiver on the audio panel and raise its volume.
- Check that the microphone selector points to the same COM radio before transmitting. The cyan tuning box does not select the transmitter.
- Verify that the facility is operating and close enough to receive. VHF communication is largely line-of-sight, so terrain and altitude matter.
- Check the avionics master, audio panel and any simulated radio failures if both COM radios are silent.
If the active ATIS frequency produces no sound, our ATIS reception checks cover receiver selection, audio monitoring and radio power.
Why does a tuned NAV frequency not move the CDI?
Tuning NAV1 or NAV2 does not automatically change the G1000 from GPS guidance to radio navigation.
Use the CDI or source control to select the matching receiver, usually shown as VOR1, LOC1, VOR2 or LOC2 rather than GPS. For a VOR, set the required course with the CRS knob and confirm a valid signal. Identify the station where the operating procedure requires it; a frequency alone does not prove that the intended facility has been received.
For autopilot tracking, use NAV mode for normal VOR or course tracking and the aircraft’s approach mode when capturing an ILS localiser and glideslope. Our practical VOR receiver and CDI workflow explains the source-selection and identification steps in more detail.
Will loading an ILS approach tune NAV automatically?
Automatic ILS tuning depends on the G1000 version, aircraft installation and simulator implementation. Some systems place the localiser frequency into a NAV standby field, while others require manual entry; always verify the receiver, active frequency and CDI source.
Use the published localiser frequency rather than the runway heading, ATIS frequency or a similarly numbered nearby facility. See our guide to finding and verifying the correct ILS frequency when the approach chart lists several radio frequencies.
What changes when tuning a simulated G1000?
Simulated G1000 units use the same standby-to-active workflow, but their mouse hotspots, controller bindings and avionics depth vary by aircraft.
- Make sure the pointer is over the correct part of the concentric knob: outer for MHz, inner for fractional digits.
- Do not use the FMS knob for COM or NAV tuning. It controls flight-plan fields, menus and page groups rather than the radio frequency boxes.
- If a hardware control changes COM1 when you intended COM2, inspect the binding itself; hardware assignments may target a fixed radio rather than the cyan on-screen field.
- If ATC or an assistance feature keeps replacing your frequency, disable automatic radio management or take manual radio control.
- Custom aircraft may replace the simulator’s standard G1000 logic, so use that aircraft’s documented click zones and control assignments.
When none of the radio knobs respond, follow our checks for unresponsive G1000 controls and frequency fields; the usual causes are the wrong knob, an inactive cockpit interaction, missing avionics power or a conflicting controller binding.