Showing posts with label alaska. Show all posts
Showing posts with label alaska. Show all posts

1 Aug 2016

More VLF from Alaska

From Laurence KL7L. This was posted a few days ago to a Yahoo group..
Been fairly active on VLF tonight with a lot of active Chorus and noise bands up to 9KHz at times – not as noisy as this.

Local thunderstorm after noon a week or so back – I'm running a slow instance still on 8kHz if someone want to shove up a carrier or two.




73 Laurence KL7L
Aspire and 7m vertical wire on a dock by the lake 100m of cat5.
UPDATE 0821z: Several German stations are still testing (radiated transmissions) at 8.27kHz and 2.97kHz. DK7FC has still to be received on ULF in the UK with Paul Nicholson in Todmorden unable to see anything at all after 9 days looking in very narrow bandwidths. Paul is till trying different settings of filters.

5 Jun 2014

HAARP to be saved?

The (controversial) HAARP project in Alaska is closing and the facility being dismantled, but scientists are trying to save it. See http://www.adn.com/2014/06/03/3500302/scientists-make-last-ditch-effort.html?sp=/99/100/&ihp=1 .   There have been all sorts of conspiracy theories. One of the objectives was to generate uW or mW level ELF signals (to communicate with submerged nuclear submarines) by heating the ionosphere with AM modulated HF signals.
http://media.adn.com/smedia/2014/05/14/19/42/1qEGYg.AuSt.7.jpeg
"What a shame if they have to tear it down, they just finished the build out to the full array a couple of years ago!
I was fortunate to get a tour of the site about 10 years ago as my friend Steve W4YHD was the Chief Engineer, quite impressive! I have some photos (35mm film, not digital) which I need to scan.  The HAARP transmitters were true AM transmitters as they were used to heat the ionosphere and generate e.l.f. waves by modulating the carrier with low frequency audio tones, very inefficient (but all elf transmission schemes suffer from lack of efficiency),many megawatts of HF energy used to excite milliwatts (or perhaps microwatts?) of elf radiation from the ionosphere.


    I recall that they had a Radar on site and were supposed to shut down in case an aircraft flew through the beam. They also had an ICOM R72 receiver so they could listen before transmitting so as not to cause QRM !  The whole lashup was powered by a series of 5 generators driven by diesel locomotive engines.   The transmitter was actually a bunch of final amplifiers, solid state driver and a 3cx5000 PA tube, housed in trailers below the antenna array, each trailer housed a number of 3cx5000 PA's - the PA's were fed by an HP synthesizer (don't recall the model #, might be in one of my photos) and fed with equal lengths of coax so all PA's would be in phase. There was a method to shift the phase across the array so as to change the shape and direction of the beam. The antennas were bow-tie dipoles broadband from 3-10MHz.  The whole thing was controlled by Sun Sparc workstations from a master control room.  Just for fun I tuned up one of the transmitters on 7.290 MHz AM to see if I could strap Ashtabula Bill W8VYZ, of course it was daytime and I don't think anybody was affected!

   Was hoping to make a return trip to see the fully built out site but its looking very questionable at the moment.

73 Warren K2ORS"