Volcanic ash and propagation

My son, his wife and 1 year old son are currently stuck in Los Angeles: all came down with a virus and were unable to travel back to the UK after a 2 week holiday. Not that they could have flown anyway, because all the planes were cancelled as a result of the Icelandic volanic ash. They are now stuck there until May 1st, the next available flight, and that is assuming the volcanic ash is not an issue then.

An upside of the flight ban are the beautifully clear blue skies in the UK completely devoid of vapour trails for days now. Not sure what effect, if any, this has on VHF/UHF tropo or even sporadic-E conditions.

DX birds: swallows have arrived

This morning I saw that the first swallows of the spring had arrived in our village. The swallows fly from Southern Africa all the way to Europe every spring arriving between late March and the end of April. Many nest in the same nest for years and years. The returning swallows, house martins and swifts remind me that this magical journey has been done for thousands of years and that we humans are just one small part of the Earth's diversity.

New 80m AM transceiver kit from Small Wonder Labs

Dave Benson K1SWL has produced a QRP 80m AM rig with a crystal controlled TX and 50kHz tunable receiver. Full details at http://smallwonderlabs.com/Retro-75.htm including a PDF builders guide. There is also a Yahoo Group at: http://groups.yahoo.com/group/SWLRetro75/

VLF amateur DX in Poland (290kms) on 9.6kHz

Marcin SQ2BXI has sent me this message today (April 17th 2010):

In last night we have VLF eksperiment in 9,6kHz in SP2KDS Club.Club signal copied Jacek SQ5BPF -distance 290km.
Movie tranmiter: http://www.youtube.com/watch?v=2sn6AmpkwlU&feature=player_embedded
and Polish page: http://www.sp2kds.pl/136khz/298-pierwsze-proby-nadajnika-w-pamie-marzycieli.html

Next experiments will soon have to 8.970kHz...
73! Marcin SQ2BXI

Next 8.97kHz German test delayed 2 weeks

Stefan DK7FC says it will be a couple of weeks before his next VLF test transmission on 8.97kHz. This gives me more time to get the RX ready.

Icelandic fireworks - lots more to come?

Volcanic activity on Iceland appears to be getting worse with more activity recently. Disruption to air flights in the N.Atlantic may become more common. See this article in New Scientist.

Ham and other books on eBay - still time to grab a bargain

My ham and other books including some magazines about the remote island of Tristan da Cunha (ZD9) selling on eBay still have a few days to run, so you still have time to get a bargain. Check out http://myworld.ebay.co.uk/rlapthorn

Even greater DX on 8.97kHz?

Stefan DK7FC has now got his 600W 8.97kHz VLF PA working and is waiting for a windy day to get his kite supported antenna up in the air. With a few dBs more power and more well-equipped stations listening/watching on 8.97kHz (33kms band) Stefan is hoping that >1000kms can be spanned in the next test transmission.

Rockmite 20m kit (unbuilt)

For some time now I've had an unbuilt Rockmite 20m QRP transceiver kit waiting to be put together. The problem is I have so many other things on the go that a 20m QRP kit is way down the list and 20m was never my favorite band: I'd wanted a 40m kit but they only had 20m ones in stock when I bought it over a year ago. The kit has never been opened and I'm thinking about putting it on eBay. The current price for the kit in Europe is 45 euros plus shipping.

What would be a fair price?

Free power transmitters

Mike AA1TJ has sent me an interesting letter about using thermoelectric modules to generate a few milliwatts of power from body heat. This got me thinking about the other ways of "harvesting" free energy from vibration, movement, heat, mains hum fog, RF from radio stations etc. One bizarre idea from a few years back was a leg-brace that powered a mobile phone by leg movement (see left). There are ICs coming onto the market that scavenge energy from various sources allowing low powered devices to be powered for free. The challenge for us QRPers is to think of creative new ways to generate a few milliwatts to get signals across oceans. Who will be the first to work DX using RF rectified "off-air" from the local FM radio or TV transmitter?