The 500kW transmitter from 1972 in my earlier post (from Funkschau Sep.1971) was the first of what betwen 1972 to 2013 became the biggest shortwave broadcasting facility in Europe. It was located in southern Germany and was originally operated by Deutsche Bundespost, and later by Media Broadcast GmbH. Before the site was closed, it included 14 of those 500 kW radio transmitters and two 100 kW radio transmitters. It was built in 1969 and demolished in 2014.
The antenna assembly comprised no less than 67 antennas set up as a 3-pointed star covering an area of one square mile. To connect any of the 16 transmitters to any of the 67 antennas, a two storey high cross-point switching matrix was necessary.
Only the first 4 transmitters had these monster modulation transformers though. In the 1980's - like the newer ones - they were replaced with more efficient pulse duration modulators, similar to class D amplifiers.
In the 1990's Harris came up with even more efficient pulse step modulation.
https://commons.wikimedia.org/w/index.php?curid=40603993
AM transmitters - so they still exist - are already completely solid state nowadays. A 600kW unit consists of 12 cabinets filled with 600 identical switching LDMOS power modules, each card complete with SMPS, modulator, oscillator, driver, outputs, filter.
The antenna assembly comprised no less than 67 antennas set up as a 3-pointed star covering an area of one square mile. To connect any of the 16 transmitters to any of the 67 antennas, a two storey high cross-point switching matrix was necessary.
Only the first 4 transmitters had these monster modulation transformers though. In the 1980's - like the newer ones - they were replaced with more efficient pulse duration modulators, similar to class D amplifiers.
In the 1990's Harris came up with even more efficient pulse step modulation.
https://commons.wikimedia.org/w/index.php?curid=40603993
AM transmitters - so they still exist - are already completely solid state nowadays. A 600kW unit consists of 12 cabinets filled with 600 identical switching LDMOS power modules, each card complete with SMPS, modulator, oscillator, driver, outputs, filter.
May I ask where this 500 kW transmitter from 1972 is located? Is it still operative?
Best regards!
Best regards!
When we deployed with the HAWK battery in Germany, we used to hang fluorescent tube lamps in the trees around the camp for free lighting due to our search radars.
Jan
There are stories of civilian photographers visiting NORAD (Cold War US military radar sites in Alaska and Canada) bases with those old style flash bulbs in all available pockets. If they wandered too far in the wrong direction, the flashes lit in their pockets, not ideal. That's a lot of microwaves.
All good fortune,
Chris
All good fortune,
Chris
This is probably interesting in the context of this thread, I hope...
Western Australia has what was originally a US Navy installation called 'Naval Communication Station Harold E Holt' which is now operated by the Australian Defence Force but still jointly with the US. It has a 2 megawatt transmitter, but the thing that impresses my inner child is the height of the anntennae, with the highest of the twelve reaching 387 metres.
Quote....The two million watt VLF transmitter is a product of Continental Electronics Corporation of Dallas, Texas, and operates in the frequency range of 14-28.5 kilohertz.
The adjacent town of Exmouth is a favorite holiday spot and I can still remember seeing the antennae from a long distance away, and watching them grow as the kilometres passed and then being amazed at how huge they actually were. Especially surprising was the thickness of the massive guy wires.
Some years ago the town had quite a few 1980's US market left hand drive cars getting around from when the Americans were still stationed there. The local pub is called The Potshot Inn referring to the base being a target back in the Cold War era.
The first link has all the technical detail.
https://www.navy-radio.com/commsta/holt.htm
https://en.wikipedia.org/wiki/Naval_Communication_Station_Harold_E._Holt
Western Australia has what was originally a US Navy installation called 'Naval Communication Station Harold E Holt' which is now operated by the Australian Defence Force but still jointly with the US. It has a 2 megawatt transmitter, but the thing that impresses my inner child is the height of the anntennae, with the highest of the twelve reaching 387 metres.
Quote....The two million watt VLF transmitter is a product of Continental Electronics Corporation of Dallas, Texas, and operates in the frequency range of 14-28.5 kilohertz.
The adjacent town of Exmouth is a favorite holiday spot and I can still remember seeing the antennae from a long distance away, and watching them grow as the kilometres passed and then being amazed at how huge they actually were. Especially surprising was the thickness of the massive guy wires.
Some years ago the town had quite a few 1980's US market left hand drive cars getting around from when the Americans were still stationed there. The local pub is called The Potshot Inn referring to the base being a target back in the Cold War era.
The first link has all the technical detail.
https://www.navy-radio.com/commsta/holt.htm
https://en.wikipedia.org/wiki/Naval_Communication_Station_Harold_E._Holt
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So, .... what? this means you guys drive on the wrong side of the road too? This is very distressing to hear - I'd hoped for a lot better.
Try to fix this, if you can; just a suggestion, cheers,
Chris
I should have said in my post above, this was done with valves back in the day...see the first link.
Yeah, we had to make sure the US wouldn't sell its cars here.
And I should have said I was stretching the limits of idiomatic humor. Humor is universally human, but even within a common language shouldn't be assumed to translate across even nominally similar regions. Living in America I find that folk from at least a dozen local origins don't understand/overstand the humor of other regions. When America sniffles the world catches a cold, and America is in Dire Straights. Hopefully not, we'll see.
All good fortune,
Chris
All good fortune,
Chris
I hope you know I was joking too! We actually do get some of your cars here (but not many).
India has stiff rules about cars with steering wheels on the left side, last Mahindra CJ-3B with left hand steering was made about 1967.
There is an international crop research station called ICRISAT at the edge of Hyderabad, they used to get Japanese cars for their staff, all right hand steering.
Occasionally a big American car would show up, most of those ended up as scrap, big light truck size gas guzzlers prone to rusting.
There is an international crop research station called ICRISAT at the edge of Hyderabad, they used to get Japanese cars for their staff, all right hand steering.
Occasionally a big American car would show up, most of those ended up as scrap, big light truck size gas guzzlers prone to rusting.
Holden's were briefly sold here as Pontiacs, I bought two new, still have one of them. I'm thinking of retiring it to my warehouse. Body parts are just about unobtainium - an authentic replacement spoiler cost me a small fortune last year.
The last time I saw the WLW transmitter site, they still had the magnificent art deco Blaw Knox antenna in service.
Win W5JAG
The last time I saw the WLW transmitter site, they still had the magnificent art deco Blaw Knox antenna in service.
Win W5JAG
I'm a Cincinnatian by birth and took a vacation with my grandparents to West Palm Beach at 16 (2006). I was amazed when my grandpa pulled in WLW in the car to listen to the Reds game. I had no idea radio waves can travel from Ohio to Florida. Cool stuff.
There was a time when broadcast radio stations were national (at night). The modern world is too noisy, and that's over. The internet is great and all, but it doesn't unite people in the same way.
All good fortune,
Chris
All good fortune,
Chris