http://www.crkits.com |
28 Mar 2013
More Chinese QRP radios/kits
Chinese QRP kits and ready built radios seem to be everywhere. For example, see the KN-Q7A kit from http://www.crkits.com/ . This little 40m 10W or 20m 5W QRP SSB transceiver was designed by BA6BF. Reviews on eHam.net are good (4.9/5 with 8 reports) so this is no toy radio.
I have the feeling this is an enterprising Chinese amateur making a bit of money selling a few kits rather than a major Chinese manufacturer, gearing up for the big time. However, this IS coming. Unless the big boys like Yaesu and Icom move to low cost manufacturing locations like China for the bulk of their products then their days are numbered. Honestly.
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.
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.
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.
KL1X grabber monitoring 8.270kHz for intercontinental amateur DX |
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 |
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
" - 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.
I'm not sure how others read Yahoo Group messages, but I always choose
" - 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.
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.
Labels:
afghanistan,
iraq,
voa
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?
Labels:
nantenna,
photovoltaic,
rectenna,
solar
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.
Labels:
lincoln
24 Mar 2013
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 |
23 Mar 2013
Reverse beacon Network
7MHz QRP RBN spots this evening |
Labels:
rbn,
reverse beacon network
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.
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 |
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