Amateur DX Europe to Alaska on VLF?

There has been some excitement over the last few days as Lawrence KL1X has seen a signal on 8.9700kHz when the noise was low that just could be coming from Uwe DJ8WX near Hamburg. He has tried to find out if this is a locally generated artifact, but it seems not.

KL1X grabber monitoring 8.270kHz for intercontinental amateur DX

In the coming weeks DJ8WX is moving his continuous carrier VLF transmitter (a long carrier is needed to be visible in the incredibly narrow bandwidths needed to see anything at all) down to 8.270kHz which is a clear frequency in Alaska. The Alaska VLF grabber is already active and, as soon as Uwe starts up, we hope to see a weak signal appear. If this happens this will be the very first confirmed reception of an amateur VLF signal from Europe in North America. The VLF receiver Lawrence uses is a small E-field probe antenna high up in a tree in a birch forest.

DJ8WX has been a very good signal on VLF here in the UK on my own receiving system (an 80m sq vertical loop feeding a preamp feeding a PC running Spectrum Lab with a special 424uHz bandwidth .usr file). I have not listened for Uwe recently as my loop is down but G3ZJO has copied him well in the last few weeks on his grabber.

DJ8WX's signal as seen on the G3ZJO VLF grabber

If you are interested in amateur VLF then visit https://sites.google.com/site/sub9khz/ and check out the various preamps, grabbers and DX reports. It is possible to check out activity by looking at the various grabbers (VLF receivers linked to the internet) around the world.

I've left the Yahoo KX3 group

Since its early days, I've been receiving posts from the Yahoo KX3 Group, which is a group for people interested in this Elecraft radio. It was generating a huge number of daily posts: this month people have posted 1590 messages already! As it is now rather unlikely that I will purchase a KX3 - I simply cannot justify £1200+ for a fully loaded, if excellent, QRP transceiver - I decided today to leave this group.  That still leaves plenty of other Yahoo group messages to read.

I'm not sure how others read Yahoo Group messages, but I always choose

"Web Only - Don't get notified of the latest happenings. Read messages only on the web."

I'd be unable to cope with several hundred, possibly thousands, of additional emails from groups each week. This option is always available when you join a Yahoo group, or you can do it later by editing your group settings.

Voice of America cutbacks

In my early days as a shortwave listener, the various VOA transmitters around the world were popular station targets for reports. I even copied "this is the Voice of America, Monrovia" (West Africa) on my little 4 component SW crystal set.  Now I see that the VOA is having to cut back transmissions because of the USA's budget issues. Like many shortwave broadcasters, VOA is feeling the pinch in hard times. The shortwave broadcast bands are no longer the same as they were back in the 1950s and 1960s: there are fewer and fewer English language transmissions to be heard nowadays.

As an aside, and I try to avoid political comments in this blog but feel compelled to share this, I read today that the audited costs of the Iraq war for the USA are an estimated $767bn. With ongoing healthcare and support costs the final figure will be well over $1trillion. All nations make mistakes and enter wars they later deeply regret, including the UK. What saddens me is the total WASTE this represents: Saddam was no saint, neither are the Talibhan in Afghanistan, but there has to be a better way to change nations. The phrase "swords into ploughshares" comes to mind. Jaw jaw is better than war, war. Just think how $1 trillion could have been better used.

Rectennas and solar energy

Recently I read about some interesting work on Rectennas, which are combined antennas and rectifiers used to detect microwaves and optical frequencies. The work suggested that very high efficiencies may be possible at optical frequencies (around 70%, possibly more) using nanotechnology leading to much more efficient power conversion of solar energy. The correct term for these would be Nantennas. At my new house (move coming up in a few months) I will be considering the installation of solar photo-voltaic panels, but wonder if I should wait a few years in case technical breakthroughs with Nantennas could revolutionise these?

Back from Lincoln

For the last few days we have been on holiday in Lincoln, staying at the Old Palace Hotel (I an highly recommend this) just below the marvelous cathedral. Our room was high up and looked due south and had an excellent take-off.  Sadly I brought no radio gear with me though, so was unable to take advantage of the site.

Clear air forward scatter optical kit

The schematics below are of the RX and TX used in the recent "over the horizon" NLOS 481THz optical tests. As you can see, not too much complexity involved considering the useful science that results. All parts are inexpensive and readily available. Nothing critical apart from the PIN photodiode and the 280000mcd red LED which I got from Hong Kong via eBay. 100mm optics used at the TX and RX ends.

The 481THz receiver

The 481THz beacon transmitter

Reverse beacon Network

7MHz QRP RBN spots this evening

The Reverse Beacon Network is an extremely useful resource. This evening, in addition to several QRP QSOs on CW, I got quite a few RBN "spots" proving just where my signal was reaching and at what strength. This is a bit like the WSPR database but for CW. As such signals have to be stronger to be copied than for WSPR but it is helpful.

More books on eBay

A couple more books have been listed on eBay this afternoon which may be of interest to readers. They are the RSGB's latest VHF/UHF handbook and the Backscatter Technical Compendium with articles from Backscatter (UK Microwave Group) from 2004-2008. The auction ends next weekend.

I have an almost complete set of SPRATs from the early 1980s to today that may be listed soon: as I have the CD, the paper copies are taking up shelf space. Paper copies are easier to thumb through though, so I may decide to keep these. We'll see.

There are a few other books and some baby clothes too if you, or your XYL, are interested. My aim is to declutter the shack as much as I can before the house move. The other books include some on disability related subjects, psychology and the Galapagos Islands (the latter is a very nice BBC book).

Last week's auction was very successful with all the books (and the fireplace surround!) finding new homes.

eBay is quite fun in small doses: I don't like to do this all the time - too much trouble packaging and labelling things and making the trip to the post office to send them off, but from time to time it is fun, especially watching the last minute rushes!

More books, including a few more obscure non radio related ones, will be listed next month.

More K1 fun

http://www.elecraft.com

Since getting my Elecraft K1 out of "hibernation" a few days ago I've had some lovely contacts with it on 40 and 20m as well as plenty of reverse beacon reports on 40, 30, 20 and 15m CW. I'd forgotten quite what a gem the K1 really is. No great DX - all the QSOs have been around Europe - but all at 5W with just the fairly basic Par 10/20/40 end-fed antenna. The receiver is lovely with signals just appearing nice and clearly, even QRP signals, out of the quiet background. This is not a synthesised rig and it sounds more like my old FT7 which had an excellent receiver.  Sensitivity is pretty good, and certainly fine for working other QRP stations around 7.030 and 14.060MHz, the QRP centres of activity.

FT817ND prices at Waters and Stanton

Looking on the Waters and Stanton website I notice they have increased the price of the FT817ND by around £30 to £565.95, despite the Yen exchange rate improving (in W&S's favour) by around 10%. I was rather hoping that the revised price might be nearer £499 i.e. downwards.

Would W&S care to comment on why the price has gone up suddenly by so much?

Perhaps there is a very good reason. To help everyone understand what I mean, see the BBC currency graph for the Yen over the last 12 months.

http://www.bbc.co.uk/news/business/

Looks to me like the UK pound buys a LOT more yen than in the summer of last year. Come on W&S, tell us what's going on.

UPDATE: I am being told the price in the USA has risen by $50 recently so maybe the rise is being driven by Yaesu? If so then they could be in trouble: falling handheld sales as a result of Chinese competition may be forcing them to squeeze for profits elsewhere? The slippery slope to niche markets and ...?