F.A.Q. is self-explanatory, we collected frequently asked questions and presented answers to them. In time F.A.Q. will grow bigger.
The S-Meter shows the signal level in the RX filter bandwidth.
When no antenna is connected, the S-Meter shows the level of the radio's internal noises.
The readings depend on the filter bandwidth, if you set SSB mode with 3 kHz bandwidth, the readings will be at the higher level, if you set CW with 100 Hz bandwidth, the S-Meter readings will be lower.
The radio's internal noises also depend on the Preamp level (sensitivity). If you set -20 dB ATT, the sensitivity will be at its worst and S-Meter readings higher, if you set Preamp +10 dB, the sensitivity will be higher and radio's own noises will be at its lowest.
S-Meter in the ExpertSDR2 has two different calibrations for HF (0-30 MHz) and VHF (30-300 MHz).
HF and VHF signals with the same dBm level have different S-scale values.
You can find calibrations tables for HF (table 3) and VHF (table 4) at the following link http://hamwaves.com/decibel/en/
29 MHz -127 dBm ~ S0.5 (preamp on)
52 MHz -127 dBm ~ S3.5 (preamp on)
To verify you may connect a signal generator to an antenna port and compare the generator signal with the S-Meter readings for all S-levels, compare to tables from the link above.
Also, you can see the IARU recommendations for HF and VHF S-Meter calibration at the following link https://en.wikipedia.org/wiki/S_meter
For HF S9 = -73 dBm = 50 uV (50 Ohm), for VHF S9 = -93 dBm = 5 uV (50 Ohm).
S-Meter in the ExpertSDR2 corresponds to the IARU recommendations, each device is calibrated at the factory during manufacturing.
When you operate in DIGI modes you need to carefully adjust VAC gain. In this case you need to adjust VAC gain for TX mode (Options-> Device-> VAC-> Receiver1(2)-> TX Gain). Also, we recommend to set Mic level indicator and control the signal level. DIGI modes signal should be around -3...-1 dB.
Note: TX Gain parameter might be either negative or positive, depending on whether you want to amplify VAC signal or attenuate it.
The Windows gain settings also can be used for gain adjustments, but we recommend to use only ExpertSDR2 gain settings.
SunSDR2 PRO TRANSCEIVER
To RX on these frequencies, we'll recommend to us the ADC IN because standard antenna inputs will have low sensitivity.
Maximum allowed signal level on the ADC IN connector is 0.3V of the active voltage (RMS). Do not exceed it, it may result in the transceivers overload and ADC fatal damage.
ADC cannot receive DC, receiving available from 9 kHz and higher, never tested below 9 kHz.
RX below 100 kHz will have low sensitivity, we've never tested our devices on these frequencies.
SunSDR2 QRP TRANSCEIVER
LED is stable (NOT blinking) - transceiver is ready for operation and can be connected to the ExpertSDR2.
In the SunSDR2 QRP we used an advanced stack of a local network, so you have 4 options for local operation:
1. DHCP Auto mode is set by default. It works this way: in the beginning, transceiver works in DHCP Client mode and tries to get the IP-address automatically from an external server, if it gets the IP address, LED will stop blinking, becoming stable green color. If transceiver can't get the IP address within ~20 seconds, it will automatically turn to DHCP Server mode and provide IP address, in this mode LED will become stable orange.
2. DHCP Server mode is for direct connection of the transceiver and a PC. In this case, the transceiver will provide a PC with the correct IP address, so you don't have to adjust network card settings. In this mode, LED will become stable orange. in this mode, the transceiver will also have a static IP address 192.168.16.225.
3. DHCP Client is for connection of the transceiver to the home local network, where you have a DHCP-server, which automatically provides IP addresses, for example, router or ADSL-modem. In this mode, LED will become stable green.
4. Static IP, in this mode transceiver, has a static IP address, works the same as in SunSDR2PRO - in this mode LED will become stable orange. By default, IP address is 192.168.16.225. This mode requires to set up PCs network card according to the same instruction as for SunSDR2PRO. We do not recommend to use this mode without special need.
Note: if you have a direct connection, after initialization process you may change a network mode to DHCP Server, this will save you about 20 seconds after switching on.
3) In the OmniRig settings (in the ESDR2) set the Enable checkbox.
4) Press the Configure button to open the OmniRig SW settings window.
5) All further information you can find in the User Manual-> CAT Menu.
Then you set up the OmniRig to operate with a certain transceiver via a certain COM-port.