1. 

   Mike Loukides (W1JQ) on January 6, 2016 at 5:20 am

   You made me poke around, and LW transmitters with output power in the 2MW range are still commercially available. Apparently solid state final amplifiers, rather than tubes.

   Which of course doesn’t mean that the stations aren’t going off the air. Wonder who Thomson is selling those transmitters to, though? China has some monster MW stations, but I bet they make their own transmitters.

2. 

   Doc Searls on January 6, 2016 at 6:35 am

   Thanks, Mike. Good find.

   Looking in my 2010 World Radio TV Handbook (the last one I bought), I see about twenty 1 to 2-million-watters scattered from Europe and North Africa to East Asia, Indonesia and the Phillipines. I wish there were a list of up and down MW stations in Wikipedia, as there are for LW here. That list has lots of high power stations among the defunct. (And there are many more off the air than on.)

   Could be China doesn’t make their own high-power MW transmitters because the volume of demand is low. No idea, though.

   It is also interesting to look at the World Atlas of Soil Conductivity. LW and MW transmission across distances depends utterly on ground conductivity, and the variation is high. On 570am, WNAX covers large portions of big prairie states by day with just a 5kw signal, because the ground conductivity there is in the 15-30mhos range. For the same reason KLIF in Dallas, on the same channel, covers most of Texas and Oklahoma. Meanwhile, look at what WMCA in New York does on the same channel with the same power, just covering New York’s inner suburbs while being utterly defeated by the minimal ground conductivity of Long Island (just 0.5mhos). Also note how well the signal travels over sea water, which has a conductivity of 5000 mhos. That’s why so many AM stations, including WMCA’s are sited in salt water tidelands, such as those in New Jersey, which bristle with AM towers.

   Ground conductivity is good (10mhos) in North Africa and Saudi Arabia, outstanding (30mhos and more) in much of Russia and most of the former Soviet states, awful in the Baltics (like Long Island and worse), excellent in the Netherlands, fair to good in most of the UK, mixed in Eastern Europe and the Balkans, mixed to poor in Greece, awful in Korea, good to okay in India, mixed in Japan, excellent in Thailand, mixed in southern Africa, mixed in Central America, awful in Canada except for the south central prairie adjacent to the Dakotas, good in coastal South America and poor in the interior, fair to excellent in Australia, poor in most of New Zealand, and mixed in China. (Just from a quick look.)

   I sense some degree of correlation between good ground conductivity and reliance on large MW transmitters. So we get the big ones in Russia and the former Soviet states, Hungary, the Philippines and Indonesia — and either littler reliance on MW (Finland and Sweden) or a complete abandonment of it (Norway).

   I still don’t know what contributes to ground conductivity, by the way. Or not exactly. Interesting topic, though.

   In a lot of regions (e.g. North Africa), MW is still a useful way to reach rural populations with little or no cell coverage. But then, there’s also satellite radio, which now serves much of the world — though admittedly in cases like ours in the U.S., from just one company.

   Bonus link.

3. 

   Jack Brighton on January 6, 2016 at 11:43 am

   Excellent post, Doc. I have two things to offer as comments:

   – I started the largest chunk of my professional life (so far anyway) as a producer at a public radio station. When the web came along as a new thing, I thought I saw that it would become the medium of choice for a growing number of people and applications. Broadcasting would be relegated to a supporting role, or as a tributary to the online river of content. (Your metaphors may vary.) It took a few years but this is happening, for much of the world.

   – But broadcast radio remains incredibly important for some of the most endangered people and cultures. For example in Central America, where indigenous people like the Lencas and Mayans struggle to maintain their communities and even their languages in the face of pressures (oh let’s just say it, blatant oppression) by governments, drug cartels, and corporations who want their land and labor. Radio is about the only medium they can deploy themselves to communicate in the remote places where they still have communities. Just about all the broadcasting infrastructure in these places came from discarded and recycled transmitters and other studio equipment cast off by us Norte Americanos. So as we increasingly get out of the broadcasting business, eventually so will they.

4. 

   Doc Searls on January 7, 2016 at 1:49 am

   Thanks, Jack.

   To your first point, word comes from Nielsen that music streaming over the Net was up 93% in 2015 over 2014. This will only continue as phones and other personal devices become nearly everybody’s radios.

   And you’re right that radio is hugely important to “remote places where they still have communities,” and the dependence of those places on discarded gear. Old transmitters from the U.S. and Canada often find their way elsewhere. Those are ideal for covering regions. But the handiest way to cover a community is with a low-power FM transmitter, and those are available over the Net for a song. With FM you only need a whip antenna or a short length of wire to radiate the signal, rather than the whole tower that AM requires. And if you put the antenna atop a building, a hill, or even a tree, it can cover a few square miles with only a few watts.

   For more about how easy that is to do, see my two pieces on pirate radio that I’ve added to the list of bonus links at the bottom of the post above. (I get about 20 pirates on a weekend evening from my low-floor apartment in northern Manhattan. All are in Spanish or Caribbean dialects and appear to come from this end of the island and The Bronx.)

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