K4TWJ (the "One Transistor Marvel" man)

Yesterday I heard that Dave K4TWJ is in hospital having had a massive heart attack on New Year's Eve. His XYL Sandy, WB4OEE, reports that he is improving and getting stronger. Dave writes articles in several US magazines including CQ and his design for a very simple one transistor transceiver appears in the International QRP Collection book available from the RSGB.

Simple LF/MF QRP transmitter

VE7SL has a neat little LF/MF TX circuit on his website which is suitable for QRP 136 or 500kHz operation. Its original application was for 160-190kHz part 15 "lowfer" beacons in the USA. I used the same PA arrangement in my first 500kHz transverter and I can confirm it is very reliable and robust.

Overnight on 500kHz (1mW ERP)

21 unique stations reported hearing me on 500kHz WSPR last night, but still the 1000kms target has not been reached - so close but so elusive. On RX, I was able to copy LA3EQ, PA0A and SM6BHZ as well as the local Gs, but no transatlantics.

Latest sunspot predictions

The recent upsurge in sunspots has been a good sign that we are now strongly on the upward curve of cycle 24 at last: most days there are spots and the solar flux levels are climbing. However, this is in line with NOAA predictions and their latest table of expected sunspot numbers is unchanged, I think, with a peak smoothed sunspot number of 90 expected in  May 2013.

500kHz looking like 30m!

Just look at this WSPR screen from 500kHz at 2330z this evening. There are G, PA, LA and SM signals coming through pretty well. 500kHz is now getting quite busy at night and it's harder to find a clear spot in the 200Hz WSPR sub-band!

Google ads quirk

Since I mentioned the Flea QRP transceiver some of my banner ads have come up advertising Flea spray! As I've mentioned them again I expect they will remain until I use some other key words in my text.

Self assembling solar cells?

Interesting article on the BBC Technology page about a possible technique for "self assembling" solar cells and other electronics products. See http://newsvote.bbc.co.uk/1/hi/sci/tech/8452912.stm

Yet another try at 1000+kms on 500kHz

Overnight tonight (Tuesday/Wednesday) Martin OE5HYM will be listening for my WSPR signals. Martin is 1128kms away in Austria and he has a well-equipped receiving station. So, I am hopeful that breaking the 1000kms barrier is now just a matter of time. With luck, there will be more stations in the 1000-1200kms range staying on overnight too. However the solar conditions appear less favourable for LF propagation tonight.

Another try at the 1000kms target tonight

Again there are a LOT of stations in Europe listening on 500kHz WSPR and I've already had reports tonight from stations 685, 701 and 896kms away from me. The beacon will again be run through the night to see if anyone over 1000kms away manages to decode me. Unfortunately I think the main problem will be there won't be anyone listening in the 1000-1200kms range: TF3HZ is much further away (1836kms) and the station in Poland and one near Stockholm seem to have gone to bed and switched off :-(

Sixbox video added

As promised, I've put a small video about the Sixbox 6m AM transceiver on my YouTube channel. You will recall that the Sixbox was a small 40mW AM transceiver derived from the 2m Fredbox. This version is built "ugly style" in a diecast box and has a tunable receiver covering about 5MHz around 49-54MHz. The Sixbox is described in SPRAT 140 and also in the German magazine QRP-Report. It is also described on my website.