ADS-B Receiver Upgrade

I've been running a PiAware receiver for a friend for over a year now, and just recently he sent me a new RTL-SDR and antenna, to try. The New RTL-SDR has a built in RF amp and a filter for the 1090Mhz ADS-B band.  The results are very impressive, with regular tracking of planes out as far as 450km. The Pi and RTL-SDR is siting on the floor in the lounge-room, near the front window, with the antenna wedged into the top of a chair on the balcony. We will work of a better option for the antenna!

Screen Shots of the Flight-aware page

 The new RTL-SDR with RF Amp and 1090Mhz Filter

 

 Antenna location (Temporary.... but for how long?)

This is the view out to the West-Northwest!

 Before the upgrade

 After the upgrade!

SM1000 Software Update!

What is an SM1000, I hear you ask?

The SM1000 allows you to run FreeDV without a PC. Connect the SM1000 to your SSB radio, and you now have Digital Voice (DV). You don’t have to buy a new radio to run Digital Voice! It’s based on a STM32F4 micro-controller, has a built in microphone, speaker amplifier, speaker, and transformer isolated interfaces to your radio. It’s just 80 x 100mm, and can be held in you hand and used like a regular PTT microphone. Or it can sit on your bench and work with your favourite headset.

The SM1000 was developed by David Rowe VK5DGR and Rick Barnich KA8BMA.

Click here for more information.

This week there was a long awaited software update (v.2) that added a menu system and the addition of the 700D mode to compliment the 1600 mode.  After performing the update, which went well, I check the menus and found a small bug.

The menu structure looks like this:

    -> Root menu:
        |---> "MODE": Boot-up Operating mode
        |       |---> "ANA":    Analogue mode
        |       |---> "1600":   FreeDV 1600
        |       '---> "700D":   FreeDV 700D
        |
        |---> "TOT": Time-out timer
        |       |---> "TIME":   Total time-out period (0 == disabled)
        |       |               0-10 minutes in 5 second steps
        |       '---> "WARN":   Warning beep period (0 == disabled)
        |                       0-${TIME} seconds in 5 second steps
        |
        '---> "UI": User interface options
                |---> "FREQ":   Morse frequency
                |               50-2000 Hz in 50Hz steps
                |---> "WPM":    Morse send speed (PARIS standard)
                |               5-60 WPM in 5 WPM steps
                '---> "VOL":    Menu volume
                                1-15 units.

After the update I could not access the UI menu (not a major issue as the original software (v.1) didn't have a menu system at all).  I informed the development team and a fix (v.3) came through (from David VK5DGR) within a few days.  This corrected the original bug but then added another.  It seems that now I cannot store a default Boot-up mode. The mode must be set manually first before TXing.  I guess this is the nature of software development.  I think I have just become a software tester and in a small way I'm contributing to its ongoing development.

Note (28 July 2019): -  On further investigation I can confirm that there were two bugs. The UI menu has been fixed. but the boot-up mode bug (which was also there in v.2) is yet to be resolved.

Watch this space.

WSPR from the Balcony

My AR activity is limited due to living in a flat, but I did run WSPR (rx only) overnight on 40m and some interesting results came in. The antenna was a Mag Loop (not very well tuned, I might add) and the balcony faces Northwest. The following is what we managed to decode: -

The interesting thing is the reception of the VK stations, as this path is blocked. I suspect that these signals are received long-path.  See the table below (click on the image to expand it): -

VK4AQJ came in at a SNR of -6 and -11 respectively, whilst all the other stations were in the -19 to 30 range (similar to the European stations).  This would seem to indicate that the VK4 may have been short-path.  All interesting stuff!  More testing required, I think.

Whilst I have been a licenses Amateur for many years, I have spent little time on the HF bands, so still have much to learn, especially regarding propagation.