diff --git a/Microphone-Transceiver.md b/Microphone-Transceiver.md
index 625ea72..2ed8bb3 100644
--- a/Microphone-Transceiver.md
+++ b/Microphone-Transceiver.md
@@ -177,6 +177,8 @@ Once is marked , we have a common same frequency (F = F_TX) and therefore, to no
 
 * **TX-IQ-CAL:** TX I/Q channel phase calibration, to adjust the imbalance IQ modulator phase error. The adjustment range is (+4º ...-4º). Specially usefull to optimize the SSB (USB-LSB) or DSB-SC , Suppressed carrier . 
 In Hackrf versions r1 to r8 , we are using max2837 , that has a calibration register settings of 5 bits , in Hackrf r9 , we are using max2839, that has 6 bits to cover the same range (+4º,..., -4º phase adj).
+At the moment we do not have any automatic IQ imbalance phase error calibration process.
+You will need some other SDR receiver , and check the suppressed carrier level when you push PTT _TX in SSB (USB or LSB) without any modulation, and then go to the right modify the "TX-IQ-CAL" value , and press again PTT_TX till getting the lower attenuated "suppressed carrier.
 
 As example , see the attenuation of the residual SSB carrier effect, when adjusting that IQ Phase calibration value in an H1R1 with max2837,