diff --git a/docs/impl/reports/SIM7600-SETUP.md b/docs/impl/reports/SIM7600-SETUP.md
index 46c7848..48e3ab2 100644
--- a/docs/impl/reports/SIM7600-SETUP.md
+++ b/docs/impl/reports/SIM7600-SETUP.md
@@ -145,8 +145,8 @@ brief NM connectivity-check penalty (`+20000`) after WiFi returns.
 Check: `cgps` or `gpspipe -w -n 10`. On 2026-10-07, tested indoors, gpsd saw `nSat: 10, uSat: 0`, `mode: 1` (no fix).
 Next: test with the GNSS antenna (IPEX, labeled GNSS on the HAT) with a clear view of the sky. A cold start can take a few minutes.
 
-**2026-10-09, in the car:** first fix, `mode: 3` (3D) with 4 of 9 satellites used, GPS time valid. No setup changes were needed;
-the indoor tests simply lacked sky view.
+**2026-10-09, in the car:** first fix, `mode: 3` (3D) with 4 of 9 satellites used, GPS time valid. Passive GNSS antenna on the dashboard, facing the sky. No setup changes were needed;
+the indoor tests simply lacked sky view. If fixes prove slow or drop out while driving, try an active antenna (check the HAT supplies antenna bias first).
 
 ## Rebuilding qmi_wwan after a kernel update