Skip to main content

Understanding UHF, VHF, AM, and FM in the F/A-18C Hornet

Effective radio communication in the F/A-18C Hornet depends not only on proper frequency presets but also on understanding the radio bands and modulation types used: UHF, VHF, AM, and FM. These terms describe how and where a signal is transmitted and received.

📡 Radio Bands: UHF and VHF

Band Frequency Range Use in F/A-18C Notes
UHF (Ultra High Freq.) 225.000 – 399.975 MHz Primary for military ATC, AWACS, strike coordination, and aircraft-to-aircraft comms Most default military channels are UHF
VHF (Very High Freq.) 30.000 – 174.000 MHz Used for ground comms (JTAC), ATC (civilian), and some regional towers VHF is often used for ground-based ops or coalition forces

  • The ARC-210 radios in the F/A-18C can operate in both UHF and VHF bands. Frequencies are manually entered or selected via preset channels.

  • Most airborne assets (AWACS, tankers, flights) will use UHF.

  • Ground-based assets (JTAC, civilian ATC, regional towers) may use VHF.

🎚️ Modulation Types: AM and FM

Modulation Use Case Supported in F/A-18C Notes
AM (Amplitude Modulation) Standard for aviation comms ✔ Yes Used for most UHF/VHF radio calls (ATC, AWACS, flights)
FM (Frequency Modulation) Ground forces, JTAC, and CAS ✔ Yes Typically used in VHF band (30–88 MHz); more resistant to static/interference

  • AM is default and is used for nearly all aviation communications in DCS.

  • FM is used when talking to JTACs or ground units via VHF (e.g., 30.00–76.00 MHz). The ARC-210 supports this, and DCS will auto-modulate based on frequency.

🛠️ How to Know What You're Using

  • When tuning radios in DCS, you don’t explicitly select AM or FM—the modulation is determined by the frequency entered.

  • Example:

    • 251.000 → UHF AM

    • 30.000 → VHF FM

    • 127.500 → VHF AM

  • As a rule:

    • Above 108 MHz = AM

    • Below 88 MHz = FM

    • Between 108–174 MHz = AM unless specifically in FM JTAC band

✅ Quick Comms Summary

Frequency Band Modulation Typical Use
251.000 UHF AM AWACS / Tower
127.500 VHF AM Carrier ATC / Civil ATC
30.000 VHF FM JTAC / Ground troops
320.000 UHF AM Strike package net
268.000 UHF AM Tanker (Texaco)

🧠 In Practice (DCS Tips)

  • Use AM for all aircraft/airfield comms unless you're talking to JTAC or infantry units.

  • If using SRS (Simple Radio Standalone), make sure your SRS settings allow auto modulation switching based on frequency.

  • The Hornet’s radios do not allow manually selecting modulation type—it’s automatic based on freq.

Back to top