--- a/doc/Tx-cal-theory	Sat Aug 12 08:47:09 2017 +0000
+++ b/doc/Tx-cal-theory	Sun Aug 13 05:04:48 2017 +0000
@@ -79,6 +79,19 @@
 likely be different if you are working with a different hw design such as a
 non-FreeCalypso derivative of Openmoko's GTA02 design.
 
+Update: the above calibration observations for the FCDEV3B should be held
+doubly in doubt because the calibration status of my CMU200 itself is in
+question, i.e., it is not currently known if the measurements it reports are
+really trustworthy.  After the above paragraph was written, I replaced the
+Rx/Tx module inside my CMU (the original one was good for Rx, but the Tx side
+was dead), and after this internal module replacement the power measurements
+reported by the instrument are 0.5 dB less than what it reported before.  Which
+raises the questions: are the new measurements low by 0.5 dB relative to the
+real truth, or were the old ones high by 0.5 dB relative to the real truth?  Or
+is the real truth something else altogether?  Until we raise a LOT more money
+to get this CMU200 properly calibrated, we are limited to guesswork and the
+true transmitter behaviour of our FCDEV3B hardware remains unknown.
+
 Profiles for Tx levels calibration
 ==================================