5 Jun 2013

Hamshop.cz

Although I have not used them myself (yet), www.hamshop.cz has a range of interesting and useful parts and kits available for purchase by PayPal. They ship worldwide too. Check out the page in English. As far as I can see, the prices are quite reasonable too.

Cloudbounce and scatter optical and IR tests

This morning I read a most interesting article about French cloudbounce and scatter optical tests using lasers. The article is some years old but makes a fascinating read. My own experience with clear air forward scatter at optical frequencies using relatively low powered red LEDs makes me believe that a LOT more is possible in this area. It is a bit like people saying, "UHF is only line-of-sight". Rubbish! With decent, easily built kit it is possible to copy QRP amateur signals over the horizon even at IR and visible optical frequencies.

See http://sd-1.archive-host.com/membres/up/22679775843705539/CBVUK.pdf

First Icom IC7100 review on eHam.net

http://www.icomamerica.com
This evening I noticed that the first user review of the Icom IC7100 has appeared on eHam.net. YB1FWO bought a unit in Japan and give it a 5 out of 5 score. I've not heard if this radio has appeared in the USA or European dealers. It was not priced a few days ago but I gather the UK price is just below £2000, so not a low cost product although it is a neat, multi-band (including 4m), multi-mode 100W radio.

6m WSPR and the transatlantic path by Es

6m spots - note the drift
 There seem to be more people trying WSPR on 6m than in previous years. Prompted by Nick G4IKZ this evening I have moved from 10m to 6m and have spotted CN8LI (2113km) and been spotted myself by a few G stations. On 6m the Doppler shift on signals can be quite fierce and setting the FT817 accurately on frequency is a little more tricky: I have to set the FT817 to 50.29260 rather than 50.2930kHz to get the correct frequency spots. I assume my 12 year old reference oscillator in the rig is a bit off. On inter-G signals I suspect that the Doppler is a result of aircraft reflection. On more distant DX stations I assume it is as a result of E layer clouds moving around.

Doppler on transatlantic 6m multi-hop Es signals might be a killer - I can imagine reflection points moving around in the E layer  - but if not, then WSPR would be a great way to check for transatlantic openings.

I'll leave the 2W WSPR to the co-linear vertical running overnight tonight and on a few further nights through June and July. We just need LOTS more USA and Canadian stations both monitoring and RXing on 6m WSPR.

More VLF earth mode tests

Tomorrow morning, all being well, I hope to do a further test on VLF earth mode at 8.97kHz using my new Asus X101ch netbook using Spectran software and a simpler loop preamp on RX. Initially I'll test locally to check results are as expected before venturing further with the new (simpler and smaller) RX system.

Also, I want later to try TXing with a large, single turn, horizontal loop on the ground around the garden rather than the earth electrodes. On the basis that I am coupling into the ground and utilities, a horizontal loop might be as effective at coupling as the earth electrode antenna. A straight comparison of one against the other will be worth trying.

I also want to try WSPR at VLF using both my PCs.

4 Jun 2013

2m UKAC contest


The few stations worked this evening on 2m SSB
Just for a bit of fun I went on the 2m UKAC contest this evening with the FT817 to the vertical colinear from home, not the most ideal of antennas when everyone is running horizontal beams. Nonetheless, I managed 6 QSOs in just over an hour of operating. No great DX - the best QSO was just 47km tonight - but a bit of fun. The better stations were exchanging serial numbers in the 70s (at least) and I was hearing stations working GM, GW and F. The map shows my (meagre!) QSOs. Maybe in a month's time I'll erect that big wheel here at this QTH and we can compare results v. the vertical antenna.

3 Jun 2013

iPhone and iPod Touch

My iPod Touch 4g battery, not easily replaceable, is now suffering from low capacity after being used daily for over 2.5 years quite intensively.

Of all the technology kit I have owned over the years, my iPod Touch 4g must rank as the very best. It gets used to surf the net over wi-fi, to communicate with our children and grandchildren when on holiday as well as for BBC iPlayer, music, videos, games, amateur radio applications and much more. Mine is the 8GB version but I see Amazon is now selling the 16GB 4th generation version for just £129, which is a bargain. I am sorely tempted to replace my aged unit.

For amateur radio apps that run on the iOS kit like iPhones and iPods, see http://www.g0hwc.com/iphone.html.

2 Jun 2013

4m/6m SSB/CW transceiver from Noble Radio

http://www.nobleradio.eu/files/NOBLE_RADIO_6N4_FRONTPANEL_BRANDED_small.jpg
This was news to me, but I just spotted a new, European made, high spec 20W SSB/CW 4m/6m transceiver from a company called Noble Radio on the 4m website at www.70mhz.org. To my eyes this is an ugly beast which resembles an old PMR radio, but what a good idea for a new VHF transceiver. Certainly in Europe a 6m/4m transceiver has some attraction for those interested in the lower VHF spectrum, if the price is sensible.  Wouldn't it be nice to have a 4 band (10, 6, 4 and 2m) all-mode rig from Japan or China too sometime soon. There would be a market.

Does anyone know who Noble Radio is and in which country they are located? I have no idea about price or availability.  Perhaps this is a "test the interest" concept model, rather like the Tokyo Hi-Power QRP radio of a few years ago. This was shown at a ham fair but never made it to market.

472kHz WSPR

After a few weeks break, I fired up the 472kHz kit this evening with about 5mW ERP (or less) from the 20m spaced earth electrodes in the ground. Not a lot of activity but exchanged WSPR reports with G7NKS (46km) and got a few reports from PA3ABK/2 (306km) and PA0RDT (243km). PA0A is always copyable when on WSPR as he rides above the local noise floor, unlike many others. Otherwise not a lot doing so far tonight. I guess everyone is watching football. I shall leave the kit running until later this evening to see what else appears.

One thing I MUST do is improve the 472kHz RX system as these days the noise pick-up on the earth electrode antenna is too great from local noise sources. For the new QTH I think I'll be installing a tuned RX loop and pre-amp at the far end of the garden as far from noise sources as possible. Even though directional, I suspect this will be better than the E-field probe, with the advantage that the loop may be rotated to null particularly bad noise sources locally.

1040z update: I shall leave the 472kHz running overnight but don't expect many more reports. These were the unique reports so far.

A new 23cm transverter kit from Australia

http://www.minikits.com.au/image/data/eme171_1200_files/eme23-trva.jpg
Mini-Kits in Australia has just announced a new transverter for 23cms. Based on a number of modules, it allows a complete, high performance transverter to be built. This transverter replaces earlier designs that used parts no longer available. At the time of writing there is no price shown. See http://www.minikits.com.au/eme23-trv.htm .

I am very impressed when people release kits for 23cms and higher. Designing a kit that is easy to reproduce is not an easy task, although using SMA components and printed inductors/striplines makes the initial modelling easier and less subject to variations than when leaded parts are used.