Seeing is believing: Tableau visualizing MWLIST

All medium wave stations from MWLIST, drawn with free Tableau software: the size of the circles represents the power of the stations, the colour the type of network.

Broadcasting on medium wave still is a very active part of using the electromagnetic spectrum. An unique and outstanding source of information is supplied for free by MWLIST, a team of smart DXers. They provide tons of up-to-date and precise information – down to exact locations and even offsets from the nominal channel.

By visualizing those data, you get an even better insight. Here, free Tableau Public software is (for me) the tool of choice to do just that – please see the screenshot on top of this page. You simply download the free Tableau app, and – also for free – sign up, and you are done.

For me, most striking is visualizing the spatial data, i.e. to show the transmitters at their proper place on a map. Another welcome feature is filtering the data to answer specific questions like: How are traffic broadcast stations above 1.6 MHz spread over Pennsylvania? Or: What can I expect listening on 1521kHz on a late winter afternoon in Europe? Or: Where are Chinese stations located, carrying the CNR1 programme of China National Radio? You will find screenshots illustrating these examples below.

Those are just screenshots, not active maps. If you want active maps, there is an option (WP-TAB, Tableau Public Viz Block) available for WordPress’ business version which I don’t have at hand.
But there is a simple solution: go to my Tableau Public page, download my TWBX-map “Medium Wave Station [Copyright MW List]”, and it will automatically be loaded into your Tableau Public app – after you have installed this. Then the map comes into live, and you can do all filtering, zooming etc.

[My profile photo shows a fisher’s deity in Japan, seen in October 2019 in Tokyo’s Kappabashi street. As a DXer and hobby cook, I thought location and statue being quite appropriate – thanks for asking …]

Surely, you immediately will find other ideas to realize, e.g. marking heard/verified signals by just a flag in your list and combining this with a special color on that station on your Tableau map.

Kiashahr broadcasting center of IRIB, the Iranian broadcaster, on the shores of the Caspian Sea. All three antenna sites are pinpointed on Tableau’s “Satellite” background map. Listen to the recording of IRIB Gilan (from the antennas at the left) below:
IRIB Radio Gilan, received on December 30, 2020 at 14:30 UTC in Germany.
Traffic broadcast in Pennsylvania duly follows the trail like pearls on a string, here e.g. US Highway 80 in the mid of the screenshot.
1521 kHz on a winter afternoon in Europe: What stations can be expected, and what interference should be avoided? MWLIST’s spatial data plus Tableau’s power of filtering the data and drawing it onto a map will show this at a glance.
How are transmitter, carrying the CNR1 programme, scattered over China? This screenshot will tell.

P.S.: Taking some suggestions from the fruitful discussion which follows the initial publication of this site, I like to add some more examples:

If you are looking for some challenges, a European listener may start with low-power stations in the UK (LPAM), transmitting with just 1 Watt of power, leaving 500mW from both sidebands, combined, for the audio at max. Filtering the MWLIST with Tableau Public and visualizing this by a map, leads to the screenshot below. I also attached an audio clip of Carillon Radio. Yes, reception quality of this station of the Leicester/Loughborough hospital resembles a bit the state of NHS 😉

All LAPM stations in the AM band do transmit with 1 watt of power only. They place a nice challenge for European listeners …
LPAM Carillon Radio on 1386kHz/1W, received on December 27, 2020 near Hanover/Northern Germany. Antenna: MD300DX active vertical dipole, receiver: Winradio Sigma.

A second example is even more challenging for European DXers, but not entirely impossible. The map shows some low-power Japanese service radio stations for parks, traffic, weather and harbours.

MWLIST has been filtered, so that Tableau’s map shows just the low-power Japanese service radio stations in the x-band (i.e. above 1602kHz. Reception of those stations in Europe is challenging, but possible, as …
… this recording of Tokyo Martis Radio [highlighted on the map above] on October 23, 2019 on 1663.5kHz shows at 10:00 UTC. The audio clip was extracted by DK8OK from a HF recording [WAV] at Norway’s KONG station, with sincere thanks to Bjarne Mjelde.

3 comments

  • Fascinating maps, thank you! Hunting LPAM stations sure is some nice way of killing time when HF doesn’t offer anything exiting during daytime! 🙂 BTW, here’s Carillon Wellbeing Radio in spring 2019 on 1476 kHz:

    Admittedly this is A) ~60km closer to Loughborough than Hannover and B) at the (North Sea) coastliine (+10dB), received with a 200m sheep fence attached via a wire to the car stereo antenna input (a recommendable arrangement for daytime MW DX nonetheless!). 🙂

    • … fine catch, Ollie! And when I started listening, I lived also at the North Sea (more exactling: the Jadebusen). With exactly no electircal interference at all, but under a by far much more demanding offer on HF … hitting only modest receivers, from 1968 and on … 73 Nils, DK8OK

      • Been there, done that, a few years later but still… crowded bands, hot signals and only money for at best mediocre radios with hopelessly underperforming frontends. 🙂

        The digital hash is now even creeping up the coast: I’m currently investigating a faint VDSL signal (precise 4kHz spacing between carriers) between 1.7 and 2.5 MHz that (apparently) can be seen along the Schleswig-Holstein coast, and even on the KiwiSDR in Hilgenriedersiel. But apart from that it’s still very, very quiet and much more relaxed bands meet radios with mind-boggling performance and features now… pure bliss!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s