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Updated Microphone Transceiver (markdown)

Brumi-2021 2024-02-04 15:14:51 +01:00
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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,