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Transponders vs. ADS-B Transceivers – Selection Guide

Choosing the correct ADS-B / Mode S device is essential for regulatory compliance, airspace access and safety. This guide helps you quickly understand the difference between Transponders and Transceivers and select the right product for your UAS operation.

1. Quick Overview

Transponders Mode S + ADS-B Out

These devices reply to Mode A/C/S interrogations from ATC radar and TCAS, and also transmit ADS-B Out (1090ES). Use them when you need to operate in controlled airspace or Transponder Mandatory Zones (TMZ).

When you need ADS-B In additionally, then please select pingRX Pro additionally which provides dual band ADS-B receivers.

ping200X TSO / ping200XR TSO – 250 W, fully TSO-certified.
Best choice when maximum SSR/TCAS visibility and full regulatory acceptance are required.
ping20Si – 20 W Mode S + 1090ES ADS-B Out with integrated SBAS GPS and barometric sensor.
Ideal for lighter platforms where 20 W is accepted by the National Aviation Authority (NAA).

ADS-B Transceivers In + Out

These devices transmit ADS-B Out and receive traffic (Dual Band ADS-B In). They are primarily designed for Electronic Conspicuity and Detect-and-Avoid (DAA). They do not provide Mode S replies like a transponder.

ping1090i – ADS-B Out on 1090 MHz + dual-band ADS-B In.
Approved as Electronic Conspicuity Device (ECD) in the UK and Australia.
ping2020i – ADS-B Out on 978 MHz (UAT) + dual-band ADS-B In.
Primarily intended for the United States.
ping978EC – 978 MHz Out + dual-band ADS-B In, specifically developed for the UK.
Uses a temporary self-assigned (non-ICAO) HEX address.

2. Product Comparison Table

ProductTypeOut FrequencyPower / Key FeatureRegion / ApprovalTypical Use Case
ping200X TSO Transponder 1090 ES 250 W + external TSO GPS Worldwide (TSO) ATC / TMZ / BVLOS / DAA
ping200XR TSO Transponder 1090 ES 250 W + integrated TSO GPS Worldwide (TSO) ATC / TMZ / BVLOS / DAA
ping20Si Transponder 1090 ES ~20 W + integrated GPS Europe / non-US  Electronic Conspicuity / DAA
ping1090i Transceiver 1090 ES ~20 W + dual In + GPS UK CAP1391 / Australia ECD Electronic Conspicuity / DAA
ping2020i Transceiver 978 UAT ~20 W + dual In + GPS NAA Approval Electronic Conspicuity/ DAA
ping978EC Transceiver 978 UAT ~20 W + dual In + self-assigned Non-ICAO HEX address UK CAP1391 - Supplementary Amendment (SA) UK BVLOS Electronic Conspicuity / DAA

3. Decision Tree – How to Choose

  1. Do you need the aircraft to reply to Mode S interrogations from ATC radar and TCAS, and/or will you operate in controlled airspace or a Transponder Mandatory Zone?
    • Yes → Choose a Transponder (go to question 2)
    • No → Choose a Transceiver (Electronic Conspicuity / DAA – go to question 3)
  2. What power level and certification do you require?
    • Full TSO certification and 250 W for maximum SSR/TCAS visibility → ping200XR TSO (integrated GPS) or ping200X TSO (+ separate truFYX GPS)
    • 20 W is accepted by the NAA (National Aviation Authority)and weight is critical → ping20Si
  3. In which country / region will you operate?
    • United Kingdom → Prefer ping978EC (978 MHz with self-assigned ICAO HEX address). Alternative: ping1090i if 1090 MHz is approved.
    • With member state/NAA approval → ping2020i (978 UAT).
    • Europe (outside UK) / other regions → Check national radio licence requirements and NAA approval. Common choices are ping1090i or ping20Si. For strict ATC requirements always select the 250 W TSO certified  transponder.
Important disclaimer: This guide is based on official uAvionix documentation. Final approval depends on the national aviation authority, radio licence and your operational safety case (SORA / Operational Authorisation). Always verify local regulations and contact uAvionix Europe support if you are unsure.

4. Where to Buy & Further Information

European webshop (recommended for EU customers):

Technical support & FAQs:
support.uavionix.com/hc/en-us