OpenTuner for HamTV

The OpenTuner software is designed to use a PicoTuner or a MiniTiouner together with a PC running Windows 10 or Windows 11. It is the only Windows software that supports the PicoTuner.

Settings for Receiving HamTV

OpenTuner was primarily designed to receive transmissions from the QO-100 geostationary satellite and needs some settings changed to enable reception of HamTV. The latest version can be downloaded in a zip file from this page: https://github.com/tomvdb/open_tuner/releases/tag/V0.B. Once you have downloaded the software, unzip it to a new folder.

Make sure that you have your tuner powered-up and connected by USB to your PC. Double-click the file opentuner.exe (which may just be labelled opentuner on your system) to start the software; no installation process is required. You may want to create a desktop or taskbar shortcut to this file. The first window you will see when the software opens is this:

Click on the tick boxes next to "BATC Wideband Spectrum (QO-100)" and "BATC Wideband Web Chat (QO-100)" to un-tick them. Ignore the greyed-out "ISS HamTV" tick box - this is not implemented or required.

The page should look like this. Now click on the "Source Settings" button. The window should look like this:

Select "PicoTuner" if you are using a PicoTuner, or "FTDI Module" if you are using an older MiniTiouner. Set the Tuner 1 Freq Offset to 0 and the Tuner 2 Freq Offset to 0. Set the LNB A and B Supply Defaults to Off (unless you need them) and set both Tuner Default RF Inputs to A (the top socket on the tuner, furthest from the PCB connector). The end result looks something like this.

Press "Save". Then click on the "Connect" button. The main receiving window will open. Click on the "Main" file menu and then select "Manage Frequency Presets ..."

The "Frequency Manager" window will open:

Click "Add". In the "Edit Stored Frequency" window, edit the name to HamTV, the frequency to 2395000 (displayed in kHz) the offset to 0, the Symbol rate to 2000 (displayed in KS/s) and the RF input to A.

Click Save. You may want to delete the other frequency presets if you are not using QO-100. Close the "Frequency Manager" window.

To tune the receiver to the preset that you have set up, right click on the numbers of the "Requested Freq" for Tuner 1. You may need to do this twice to get a response.

In the small menu that appears, click on "HamTV (2395000). The tuner settings should change appropriately, and the Demod State should say "Hunting"

Now is a good time to check your "RF Input Level"; the background noise from your preamp should push this to at least -70 dB. Values in the range -70 to -30 are acceptable. If the reading is between -82 dB and -70 dB, you do not have enough preamp gain for optimum reception.

Your system is now in the state waiting for reception of a HamTV transmission. When it does receive one, the readings will look like this:

Note that the Demod State changes to Lock, and the Service Name and Service Provider fields are populated. The image window at top right will remain blank until a camera is connected to the transmitter.

The D number displayed in the top right of the parameters window indicates the signal margin in dB. So when this drops to D0 you lose the signal. During an ISS pass with a 0.9metre dish, this will typically rise from D0 to about D13 and then back to D0.

If using a PicoTuner, you have a second set of receive settings and a second video window displayed. Unless you have a local signal to look at, these can be ignored.

Restarting OpenTuner

When restarting OpenTuner, you will need to click "Connect" on the first screen, and then right click the "Requested Freq" and select "HanTV (2395000)".