26 May 2008

Online SDR

http://websdr.ewi.utwente.nl:8901/ is an online software defined radio which up to 50 people can use at the same time. It covers parts of 80, 40 and 20m and works really well on my little Asus EEE PC. You need both Java and JavaScript enabled for this page to work properly. Unfortunately it does not quite tune down far enough to cover the QRP calling frequencies.

Ukraine worked on 6m QRP

UR5WD in KO20NC was the best QSO on 6m QRP (5w CW on the small vertical) yesterday. He was quite weak with me on CW and I was surprised to work him, but got a 559 report. The band was open most of the day to somewhere in Europe although the opening favoured the east for me.

25 May 2008

50mW 10m QSOs today

WPX CW contest today and 10m in great shape allowing 4 QSOs just now with just 50mW into the recently built Homebase10 wire halo antenna. These stations would have been workable at 5mW or less I believe, but I could not find a larger RF attenuator!

Worked with 50mW: DL7BY (599), DH8BQA (599), DG4R (599), EH3MM (599)

24 May 2008

New 6m country worked

Although not super DX, I worked 9H1 this evening with 5W CW on 6m. The band was in good shape with stations from all over Europe audible and even hints of transatlantic stations (8P9 worked by a CU3 and calling CQ DX Eu).

21 May 2008

6m and 10m lively this afternoon

10m was in good shape at 3-4pm today with plenty of EUs workable including a new country for me on the band in the form of LX1AX who gave me 55. He was running 1kW to a 9el yagi - rather out-doing my QRP and a halo! Still, a new 10m DXCC country is in the log.

6m was also open managing to work IK0FTA with 5W SSB and the vertical.

20 May 2008

Some life on 10m tonight

10m was open earlier this evening to ZD7X. I was unable to hear him when I got on but did work EA and EA6 on QRP SSB.

19 May 2008

Inter-G 10m DXing

Some years ago the RSGB arranged some evening 10m activity periods during a quiet part of the sunspot cycle. It was fascinating to see how far one could work on 10m around the country even with QRP SSB/CW. Contacts from here in East Cambridgeshire regularly extended to as far away as Yorkshire even with just a sloping wire dipole or CB half-wave antenna only. Contacts were often right on the edge and CW helped. I would be happy to try skeds with others in the UK on any mode on 10m although I can only run 10w maximum. I have long thought the 10m band is much under-used for local and semi-local QSOs. It is a pity there is now less 10FM activity around 29.6MHz apart from when the band is open for DX.

Through the ground communications?

Anyone experimented with "through the ground" (earthmode) communications using audio amplifiers and grounded electrodes? I have done this in the past with limited success but never used more than a few watts at 1kHz. These days with ultra-narrowband digital modes like QRSS, PSK31 ad PSK16 coupled with waterfall displays ranges should be quite respectable. My best DX was 0.3kms but I imagine this could be at least doubled using modern DSP techniques. There is some info on this on my website http://www.g3xbm.co.uk

Publicising the blog

Just announced this blog on http://groups.yahoo.com/group/GQRP/ so it will be interesting to see if anyone now reads it.

The simplest possible QRP transceiver?

What do you think is the simplest possible QRP transceiver? The Pixie or Micro80? Have you built a functional transceiver with even fewer parts than these famous QRP radios? If so, post a link. I believe it should be possible to make a transceiver with fewer than 20 parts in total.,

Elecraft K3

Have you seen the new K3 from Elecraft yet? All review comments are very favorable and it is certain to be a hit for those wanting a top of the class rig at a relatively modest outlay for a radio in its class. Although I wouldn't mind one, it is not top of my own shopping list though.

If you have used one of these rigs please let us know how you found it by posting a reply on the blog.

Fredbox 2m AM mini-rig

There have been a few recent posts on the VHFam Yahoo group from people building versions of my Fredbox 2m AM rig. This rig was first designed back in the 1970s and rebuilt a couple of years ago.

Best DX worked was 160kms across the channel to Brittany from South Devon using just a whip antenna - not bad for 10mW. A proposal for a Fredbox 2 is shown in the files section of the VHFam group. This is a DSB version based on the NE/SE602 double balanced mixer.

10m and 6m summer conditions

So far I have been disappointed by this summer's sporadic-E conditions, which have not been as good as last year. OK, it is still early days in the season and things may improve. Traditionally, early June is a good time for super DX across the Atlantic to start.

On 10m I am testing my new Homebase10 antenna. This is a wire halo antenna based loosely on the cobwebb and the GM3VLB antennas. It is called the Homebase 10 as most of the bits can be bought from the local Homebase or B&Q stores.