9.1 Voltage
11.67V
This the Digital Voltmeter (DVM) function. The measurable voltage range is 0-20V DC.
When the on-screen battery voltage display is used, you must connect the DVM input pin to the
+V output pin (refer to previous diagram showing these connections).
In this example, a 12V power supply is being used to power the radio. The DVM input pin is
jumpered to the +V output pin shown. The measured voltage of 11.67V is 12V minus the voltage
drop over the reverse polarity protection diode D3.
9.2 RF Power
4.52 W
This the RF Power meter function. The measurable power range is 0-5W. The RF power
measurement circuit uses a simple diode detector. There are non-linearities in the diode function,
and differences from diode to diode; therefore, the measured power output is not highly accurate.
However, it is certainly a very good indication and debugging tool.
Note that the RF Power meter and the DVM use the SAME Analogue to Digital (ADC)
microcontroller input. You must not try to use the RF Power meter and the DVM at the same time!
Ensure only one or the other is connected.
9.3 Audio Ch.1
01,652
This item just displays the raw amplitude number calculated by the Goertzel algorithm for the
audio channel 1, which is connected to the output of the audio amplifier. The value shown here will
depend on the input signal level but also on the gain control. You can easily verify that as you turn
up the gain control knob, the displayed value increases.
9.4 Audio Ch.2
00,008
This item just displays the raw amplitude number calculated by the Goertzel algorithm for the
audio channel 2, which is connected to the output of the phase nulling circuit. The value shown
here is independent of the gain control. The value is much less than that measured on Audio Ch.1.
This is because one ADC least significant bit equates to a voltage of about 5mV. The signal
QCX operating manual, firmware 1.07, manual edit 0.03
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