29 May 2009

6m DX to the Congo

I overheard G4DEZ telling another station that he had worked the Congo on 6m CW today. This is some distance on 6m Es! G4DEZ does have an impressive station and antenna farm but this was with 100W, so no super QRO.

26 May 2009

6m Fredbox ideas

Looking at project ideas, I am beginning to think about a simple 6m AM transceiver design. The starting point would be my Fredbox design for 2m AM from many years ago. An outline spec would be: 500mW AM crystal controlled TX, simple superregen RX, built as a small modern day "Heathkit Lunchbox" style rig with an RX tuning knob and LS. Such a simple radio would be an ideal local ragchewing radio and would give coverage up to 10-15 miles with a simple vertical colinear antenna, dipole or halo.

A very good example of a 6m superregen (also regen) RX by N1TEV can be found at http://www.arrl.org/tis/info/pdf/9712039.pdf although this is more complex than I would plan to use.

25 May 2009

6m QRPP

Worked M0BXT tonight on 6m AM when Andrew was using a single transistor TX using a carbon mic to produce AM! His signal was RS58 with me at 2 miles range but modulation depth only about 5-10%. Still, it was a QSO.

Good Es tonight

Worked ZB2FK this evening at 2126z on 50.090MHz CW. I think this is a new country for me on the band. 10m was also in good shape with lots of very strong Es DX coming through from Europe and N.Africa.

23 May 2009

Microvert antenna

Many people are looking for that magic antenna that takes very little space and performs very well on HF bands. Some examples of this claim include the cross-field antenna, the EH antenna and the Miracle Whip. Now all of these have their place. I have used a Miracle Whip and it behaves as one would expect i.e. several S points down on a full sized antenna, but it communicates. Even decent DX has been worked with one (11000kms on 5W SSB) during the high sunspot years.

This week my attention has been drawn to the Microvert Antenna (see picture of an example). Is this a more realistic attempt at an efficient, small sized HF antenna? This antenna was developed by DL7PE. The radiator for 7MHz is only 1.33 metres long and the counterpoise is 8.2 metres. the 28MHz version is very small indeed. Perhaps this is worth a try? See also the Microvert Yahoo Group.

Multi-hop Es or Es+F2?

Last night, around 2100z, 10m was open to South America by what I assume was multi-hop sporadic-E or possibly Es linked to F2 at lower latitudes. There was strong Es to Spain/Portugal at the time so the latter may be more probable. Stations heard but not worked included YP4DYP, YV5EAH and YV4DYJ all on SSB. Distance is around 8000kms - which is some distance for Es alone.

22 May 2009

A QRPer's brain

Yesterday I went to get my brain MRI scanned as part of a Cambridge University research project on speech and language. The result is attached. I spent nearly 90 minutes being scanned whilst listening to various sentences.

Someone suggested the missing top part of the brain explains why I am a QRPer!

6m Es

A good opening on 6m his evening with lots of 59+ signals from southern Spain and Portugal coming through. There are supposed to be some CN8 and EA8 stations on too but not heard or worked any yet.

15 May 2009

Some Es statistics (2008)

Check out http://www.vhfdx.net/states2008.html which has some fascinating data about the extent of Es openings in Europe in the 2008 season. At times, the MUF for Es reached 250MHz. The VHF.net has a great deal of other useful data and is well worth a regular visit.

Several stations worked by Es today - LA5AKA, SM4EXP, I0KNQ and YO2QC.

Increasing sunspot activity

Sunspot number running at 18 today, a value not seen in a LONG time and solar flux in the mid 70s. Even HF conditions shown as "fair" instead of "poor". Yet more signs we are, at last, coming out of the bottom of the cycle.