W8EMV - Whiskey Eight Echo Mike Victor

OpenWebRX+ on a Pi 400 with a AirSPY HF+ SDR and Youloop antenna

My OpenWebRX+ is now up and running in a temporary setup on a Pi 400. The biggest visible change relate to OpenWebRX is a noise reduction setting and some added digital decoders. I am still exploring all of the menus. One of the things I want to do is grab SSTV images off the air - that's possible with this config but not with the old system, but no success with it yet.

https://github.com/luarvique/openwebrx

The install was pretty easy - I used their pre-baked image for the Pi 4, burned an SD card, booted it, added Tailscale as I usually do, and all was well. In the process I lost all of my OpenWebRX customizations but they were easy enough to add back in by hand. In any case I wanted to revisit some original decisions so not all was lost.

https://github.com/jketterl/openwebrx/wiki/Setup-Guide#raspberry-pi-sd-card-images

The Pi 400 is perfectly adequate for OpenWebRX+ in initial tests, but I want to move this to a Pi 4 with more open USB ports so that I can add a second RTL-SDR tuner. I have a Pi 5 on order but no particular guarantee that the whole setup will work there out of the box without at least one tweak to some component.

The AirSPY HF+ covers broadcast AM and FM, shortwave, 20-80 meters ham bands, NOAA weather radio, pirate radio on 43 meters, the 2 meter band - basically a lot of listening. The RTL-SDR would add 440 MHz and the ADS-B band at 1090 MHz. It's also the case that though the RTL-SDR has less bits of listening precision it does cover more spectrum in one go, which is handy for watching more of the band at once.

When I do an A/B comparison between my setup and the KiwiSDR nearest by ("Pembleton Farms", in Northville Township) my configuration has more noise and can't pick up signals that are as weak. I'll chalk that up to my lack of acreage to run a big 230 meter Beverage antenna!

http://misdr.proxy.kiwisdr.com:8073

RCA Radiotron tube art

I once had one of these tubes in this box, it got lost - I regret that.

See VinylSavor for a longer story about this box art. Image used with permission.

http://vinylsavor.blogspot.com/2011/08/tube-box-art-part-1-rca.html

Radio 48 / Mix Radio International on 6845 kHz

Listening to music on 6845 kHz (Sunday 0122 UTC / Sat 823p Eastern).

HF Underground identifies it as "Radio 48"

https://www.hfunderground.com/board/index.php/topic,121380.0.html

My signal into my Youloop / Airspy HF+ / OpenWebRX in Michigan is very noisy, time to tune some KiwiSDRs....

"Pembleton Farms" KiwiSDR has a nice signal (S7) and picks up the ID on the waterfall

ID at 0127 is "Mix Radio International Worldwide"

reception reports to "[email protected]"

and an eQSL card

Tracking interesting airplanes, some ADS-B based software tools

Assume that you have an ADS-B receiver listening for aircraft. What kind of filters are available for plugging that data feed into something that you control that would emit a stream of "interesting" aircraft? And what tools would you use to build it?

The alerts I've seen have been for aircraft flying in circles ("advisory circular"), specific planes owned by notable people. I'd add anything low flying, blimps, etc.

Bonus points if you can replay recent traffic against new filters.

Some options:

plane-notify

Notify if a selected plane has taken off or landed using OpenSky or ADS-B Exchange data. Compares older data to newer data to determine if a landing or takeoff has occurred. As well as nav modes, emergency squawk and resolution advisory notifications. Can output to Twitter, Discord, Mastodon, and Telegram

This powers the "elonjet" bot.

https://github.com/Jxck-S/plane-notify

qt-adsb-alert

"qt-adsb-alert fetches informations from ADS-B exchange website and sends a mail when interesting planes are near home"

It exposes a bunch of ADS-B variables and lets you write code against them, e.g.

export function sendAlert() { var distOk = (distanceToMe < 50000) || ((distanceToMe < 100000) && (gettingCloser < 20)) return distOk // distance ok }

https://github.com/nefethael/qt-adsb-alert

traffic

"traffic" does air traffic analysis in Python

Its main purpose is to provide data analysis methods commonly applied to trajectories and airspaces. When a specific function is not provided, the access to the underlying structure is direct, through an attribute pointing to a pandas dataframe.

https://github.com/xoolive/traffic

https://traffic-viz.github.io

FCC to eliminate symbol limits on amateur radio transmissions

Dan KB6NU writes

Let the innovation begin! FCC eliminates baud rate limitation

https://www.kb6nu.com/let-the-innovation-begin-fcc-eliminates-baud-rate-limitation/

From the Federal Communications Commission:

Specifically, we remove limitations on the symbol rate (also known as baud rate)—the rate at which the carrier waveform amplitude, frequency, and/or phase is varied to transmit information1—applicable to data emissions in certain amateur bands. The amateur radio community can play a vital role in emergency response communications, but is often unnecessarily hindered by the baud rate limitations in the rules.

https://docs.fcc.gov/public/attachments/FCC-23-93A1.pdf

The ARRL reacts favorably, noting that there is still a bandwidth limit on transmissions in the affected bands.

"Consistent with ARRL’s request, the amended rules will replace the current HF restrictions with a 2.8 kHz bandwidth limit."

http://arrl.org/news/arrl-hails-fcc-action-to-remove-symbol-rate-restrictions

These limitations have been lifted temporarily in the past, when emergency traffic needed more bandwidth (e.g. for Hurricane Ida in 2021), so it's likely that once the restrictions are lifted that modem software like VARA will be able to use these new features right away.

http://www.arrl.org/news/view/fcc-grants-temporary-waiver-to-permit-higher-symbol-rate-data-transmissions-for-hurricane-ida-traffi

Regulations do not go into effect until they are published in the Federal Register (about a 30 day delay).