Author Archive
Digital systems and amateur radio?
At the moment there seem to be several competing digital modulation schemes First there was ICOM’s D-star system, then C4FM from Yaesu, and of course DMR, which is gaining ground in the commercial PMR world. There are even a few experimenting with TETRA, as used by the public services. Like Betamax and VHS, the best system may not win in the end.
At the moment, I am just not interested. I’ll wait to see who wins in the end. My bet is DMR will win in the end as there will be a plentiful second hand market from PMR. This will never be so with any proprietary system. DMR is an open standard, so there will be plentiful radios around and at decent prices before too long.
QRP SSB kits from Spain
EA3GCY sells a range of QRP kits including single band, single PCB, SSB transceivers for 20m or 40m. These look easy to build and test and good value for money. Currently there is a 5% off offer running too.
See http://ea3gcy.blogspot.it/2013/03/iler-20-4-5w-qrp-ssb-monoband.html .
See http://ea3gcy.blogspot.it/2013/01/iler-40-4-5w-qrp-ssb-monoband.html .
He also does a CW kit and other accessories. Look out for the ILER range.
Falling sunspot numbers?
Sunspot number for Dec 27th 2014 has fallen to 92 and 10m propagation is forecast to be “fair”. Although we’ll still get good days, we must now expect sunspot numbers to gradually decline as the years go by towards the next sunspot minimum. Usually the decline downwards tends to be faster than the climb after the minimum, although many are predicting that the next maximum (cycle 25) will be miserably low.
See http://www.solen.info/solar/ .
See also http://sc25.com/ .
Apple – Panorama documentary
Last week, BBC’s Panorama programme did a frightening documentary on factories used by Apple in China and on their tin supply chain in Indonesia. If such poor conditions are used by Apple, many other products will be produced in even worse conditions. As a user of Apple products I am appalled.
See Panorama, Apple’s Broken Promises .
Of course, we in the West milk the low costs that such poor working procedures/conditions permit. With time, conditions will improve and the West will look to other low cost manufacturing areas for our low cost products. Sadly, our greed feeds this process.
Frighteningly, other products we buy are probably made in places that are far worse.
Andrew G6ALB tells me of a friend in the automotive industry who visited a Chinese supplier where he found workers using ordinary sun glasses to protect eyes from welding gear. After 6 months the workers were totally blind. So they just got fresh workers to replace them!
Thanks to Steven G7VFY for most of this information.
UPDATE 1740z: Sadly many (most?) of our electronics components will be made in sweat shops in the Far East. It is very hard to get away from this problem.
Simple 10m DSB transmitter
From Steven, G7VFY comes news of a very simple 10m DSB transmitter from the blog of KA7OEI. This is an experimental very low power transmitter. It is unlikely to be of use in serious applications, but the range might surprise some. On 10m, the antenna is efficient and on a clear frequency it has the potential to get a long way. Over 1000km would not surprise me on a totally clear frequency. After all, 1mW (or so) is about 53 if a 100W signal was 59+12dB. On 10m such signals with 100W are very possible.
See http://ka7oei.blogspot.co.uk/2014/10/the-pointless-10-meter-dsb-qrp.html .
Optical communications – over the horizon (NLOS)
The DX record for communications at optical frequencies is phenomenal these days. There is a growing interest in communications over non line of sight paths (NLOS) using cloud-bounce or clear air scattering. To my knowledge, in recent times experiments are (or are about to start) by F1AVY, VK4EBP , VE7SL and G3XBM (when fit again). I am sure there are others too. Weak signal modes certainly help. I used QRSS3 over an 8.5km NLOS path, but much further has been achieved.
See http://en.wikipedia.org/wiki/Non-line-of-sight_propagation.
Australian Optical DX https://groups.yahoo.com/neo/groups/Optical_DX/info
Nanowaves https://groups.yahoo.com/neo/groups/UKNanowaves/info
W5OLF website
W5OLF’s tiny WSPR-AXE-CW |
Jay, W5OLF, the creator of the “no PC needed” WSPR-AXE-CW beacons for WSPR on 30m, 20m or 10m has just started a new website. He expects to start selling the new versions of his little beacons, either as kits or built and tested units, in late January. These stay on all the time (the PA can be turned iff) , but frequency is randomised over 100Hz within the WSPR window. Once set, the timing is fine for ages and ages – certainly days or even weeks.
Jay’s email (replace the (at) with @ ) is: w5olf(at)comcast.net .
His new website is www.w5olf.com .
I am privileged to be a beta tester of his 10m version (500mW). As you will have read in earlier posts, this unit certainly works very well, mine having been copied all over the planet in just a few weeks. Just press a button to sync time on an even minute and watch all the reports come flooding in. I was blown away with mine. Tiny, but brilliant. If you like WSPR I can thoroughly recommend this little unit. It comes pre-programmed with callsign, locator and power level.
UPDATE 1448z: This little unit has been spotted in Antarctica (13676km) 8 times today already. My antenna is nothing special, just a low 3 band end-fed wire.