The AI named Copilot helped me summarize my experience with SXTsq Lite2 "client server" connections. -- KF7YRS

2 GHz SXTsq Lite2 cannot use ham‑only channels in AP (PtMP) mode — RF not transmitting

We have identified a repeatable, hardware‑specific issue affecting the MikroTik SXTsq Lite2 (2 GHz) on both AREDN 4.26.1.0 and the latest nightly (20260514‑c527c846). The device works correctly in Mesh (adhoc) and Mesh Station modes on ham‑only channels, but fails to transmit RF entirely in Mesh PtMP (AP) mode.

This appears to be a firmware/driver defect specific to the 2 GHz SXTsq platform.

Summary of Findings

1. Mesh (adhoc) mode works normally

• Negative channels (–4..–1) appear in the setup page
• Summary page matches
• RF detector shows strong RF output
• Two SXTsq Lite2 units linked immediately on –2 (2397 MHz)
• Full mesh routing worked through the link

This confirms the hardware and RF chain are healthy.

2. Mesh Station mode also transmits RF normally

• Setup page shows only channels 1–14 (negative channels not exposed)
• Summary page may still show “–2”
• RF detector shows strong RF output in Mesh Station mode
• So the radio is transmitting in Station mode, even though channel selection is limited

This means the RF chain works in both Mesh and Station modes.

3. Mesh PtMP (AP) mode does NOT transmit RF

• Setup page shows only channels 1–14
• Summary page still reports “channel –2”
• RF detector shows no RF output at all in PtMP mode
• Field tests confirm:
  • No beaconing
  • No detectable signal
  • Clients see ~–100 dB
  • No association occurs despite clear LOS

This is the critical finding:

The SXTsq Lite2 does not transmit RF in PtMP mode on ham‑only channels, even though the UI claims it is on –2.

This is not a channel mismatch — it is a radio‑not‑keying‑up condition.

4. Behavior is consistent across firmware versions

• Confirmed on 4.26.1.0 (stable)
• Confirmed on 20260514 nightly
• Negative channels appear only in Mesh mode
• PtMP mode still shows only 1–14
• Summary page continues to misreport “–2”

5. Impact

• PtMP deployments on ham‑only channels are impossible on this hardware
• The AP does not transmit RF, so no client can ever associate
• Mesh and Station modes work, so the hardware is functional
• 5 GHz SXTsq units do not exhibit this issue

This appears to be a 2 GHz‑only driver/UI defect affecting PtMP mode.

6. Reproducibility

• Confirmed on multiple SXTsq Lite2 units
• Confirmed by two operators at different times and locations
• Confirmed with RF detector measurements
• Confirmed by successful Mesh↔Mesh and Mesh Station RF output
• Confirmed by complete lack of RF in PtMP mode

I can provide sysinfo.json files, screenshots, and RF‑detector photos if needed.