TX: Adjustment RF Power Meter
The RF Power Meter should be calibrated to show proper values. Calibration needs to be
done for some but not all bands, the software calculates the values for other bands.
1.
Choose mode LSB or USB.
2.
Choose 5W power
3.
Set "PA Configuration Menu", "Tune Tone" to "Single".
4.
Enter "PA Configuration Menu", "
xx
m Coupling Adj." (replace
xx
with 15, 20, 40,
80 ,160). You will be able to change the value for a band only if the band is
selected!
5.
Press F5 - "Tune".
6.
Set the coupling up to the point, where RF power meter shows roughly 5W.
TX: FM And Digital Modes
Please, keep in mind that transmitting FM or digital modes means there is a continuous
carrier of a chosen power present at the RF output. It is highly advisable to have an
adequate cooling of PA stage.
IQ Calibration
In the real world certain hardware-related influences affect the analog IQ signal in the
mcHF. It is not perfectly symmetrical and the phase may not be exactly 90 degrees
and/or the amplitudes may not be exactly equal. In the software domain we can use
calibration to reduce/correct this problem. This requires careful adjustment of IQ phase
and gain balance both for the RX and TX signal path. The mcHF from version 1.5.7
provides 3 groups of adjustments. 2 groups are for receive and transmission in a given
translation mode. The third group is for adjustments in case of CW transmission (and all
other untranslated transmission, which is not recommended). First of all, make the
adjustments in USB and translate mode. When complete, continue through the
adjustments for CW mode. The CW mode adjustments do not use frequency translate,
these are different software parameters to USB translate mode, so follow the
adjustments through to the end. For receive only, there is now [Valid from 1.5.8] the
ability for an automatically adjusted IQ phase and amplitude imbalance correction (see
point RX IQ adjustments).
TX IQ Adjustments [Valid from 1.5.2]
