GhostNet 1.5, page 31

31 GhostNet Receive-Only Options Persons limited by a lack of license or transceiver, but still desiring to participate in GhostNets can set up a receive-only station to listen in on transmissions. Though there are many ways of doing this, a common setup requires the following: Needed Hardware 1 - Software Defined Radio with a Windows (or Linux) PC to run it: A simple SDR dongle can be configured to receive HF radio transmissions. Some SDRs are more efficient on HF frequencies, but with an appropri- ate antenna any SDR should be sufficient. 2 - HF Antenna: Suitable for the frequencies you wish to receive. HF antennas for receiving can be built more easily than ones used for transmitting, and in a pinch a long, random length of wire will work (albeit, not very well). 3 - GPS Receiver: A simple USB GPS dongle will function perfectly. You may need to install specific USB drivers to allow it to function on your particular operation system. Needed Software 1 - A simple SDR software package: A common option is SDR# (also known as SDRSharp). This will be used for a variety of tasks, but mostly to ensure that your HF antenna and audio settings are functional. 2 - Virtual Audio Cable: A common option is VBAudio Cable. Radio signals are received by your SDR, where they are displayed as audio. That audio has to be input into the appropriate software in order to be decoded. If your radio isn’t “piped in” to software that will hear it, no communications will be heard. Since our SDR is a device plugged in to a USB hub, we have to make this connection virtually, with software. VBAudio cable is a simple software package to allow the audio from the SDR, to be input into JS8Call, instead of coming out of your computer’s speakers. 3 - JS8Call: The main software package for decoding the bulk of our GhostNet signals, which use the JS8 protocol. This program will decode the audio that is fed into it (the audio that comes from your SDR) and decode those digital signals into plain text. 4 - FLRig and FLDigi: Supplementary software that is similar to JS8 in that it decodes signals, but instead of decoding the JS8 protocol, FLDigi decodes a variety of other signals, such as Radio Teletype or RTTY. This software will be needed for GhostNet comm windows that require decoding RTTY. 5 - BKTTimeSync: Software to set your computer’s time to accurate GPS time. Necessary to decode JS8Call messages which rely on a very accurate clock. 6 - Zadig: Software to install the proper driver for your SDR device. Simplified Setup Checklist for Receive-Only JS8Call 1 - Install SDR# and Complete Setup: Install SDR Software, install appropriate drivers for your SDR dongle. 2 - Open VBCable: Download VBAudio Cable, open the .exe file, and install the driver. 3 - Insert SDR, launch Driver Replacement: Plug in your antenna to the SDR, and insert your SDR into an open USB port, and use the Zadig software to install the proper driver for your SDR (the Windows operating system will automatically install the incorrect driver for most SDRs, so Zadig is needed to correct this mistake). 4 - Note Com Port: With your SDR dongle inserted into your PC, open Device Manager and ensure that your SDR shows up under Ports. Note the Comm Port number. 5 - Open SDR#: Confirm the SDR is working by clicking Settings -> Device, and from the drop down menu, select your SDR device. You should see signals coming in on the waterfall. This program is necessary to receive signals using your SDR (if you don’t want to use FLRig/FLDigi). You can pipe the audio from SDR# directly into JS8Call using VBCable. 6 - Install and open BKTTimeSync. This will sync your PC clock to the most accurate time. This is required forJS8Call to decode messages. This app will require an internet connection (not ideal) or a GPS dongle/ internal GPS on your computer/tablet. Alternatively, you can use the Automatic Time Drift function in JS8. 7 - Install and Open JS8Call: Follow the prompts for installation. When prompted to select a rig, choose “none”. Open File -> Settings -> Audio, and under the Input drop down menu, make sure to select the VBAu- dio OUTPUT. Remember, your SDR (using the VBAudio cable software) is OUTPUTTING audio, which needs to be piped in to the INPUT of JS8Call. This “connects” the audio cable so that JS8Call can hear the audio signals that are being received by your SDR. You should now begin decoding JS8 signals. 8 - Install and open FLRig and FLDigi: These software packages can be set up in a similar fashion as JS8Call. FLDigi can be used to send and receive RTTY messages (along with many other data modes). A receive-only arrangement can be established using FLDigi as well.