23 Dec 2009

WSPR reporting - the REAL advantage

This evening, after a brief foray on 40m QRP CW, I returned to 500kHz WSPR whilst getting on with other jobs in the shack. As an example of just how good WSPR can be, see the example shown here in which one brief WSPR transmission results in no less than seven reports. In an instant I could see just where my 1mW ERP signal was getting and how well it was being received. Using modes like CW this sort of thing is just not possible. OK, it is beaconing and not a contact, but to be honest I'm more interested in testing my TX system, checking propagation, seeing how my antenna changes have affected things than having a "rubber stamp" HF QSO in which little information is being exchanged.

22 Dec 2009

40m CW with the Elecraft K1

This evening, for a change, I fired up my little Elecraft K1 4 band QRP CW transceiver that I built a few years ago. Not much doing on 20m or 30m so I went on 40m CW and worked a few stations around Europe. Worst report was 559 and the best 599. It was a change from 500kHz WSPR.

21 Dec 2009

Gnat 1 transceiver - anyone made/used one?

Has anyone here built and used a Gnat-1 single transistor transceiver? This was in SPRAT earlier this year and it was designed by Chris Trask N7ZWY. Although I've seen a few pages with photos of copies, I've not heard how well it works and what anyone has worked with one. The picture on the right is from LY3LP's website and shows his version for 20m.

Designing crystal oscillators

If you want a range "sure fire" crystal oscillator designs to suit fundamental and various overtone modes you should check out the "Oscillators" page on the QuartSLab website. This has details of circuit values and configurations that will really work. Most of these designs are ones I recognise from my days at Pye/Philips PMR, so I know they are reliable and well tried.

SPRAT on CD (GQRP Club)

An ideal, if late, Christmas present is the latest Sprat CD which has all editions of this excellent UK QRP magazine from edition 1 to 140.  Price to members is £4 and to non-members £10 plus postage.

Starting work on the 10m transceiver today

The weather's a bit warmer (0 deg C) so I'm going to start on the local oscillator section of my DSB transceiver today. Will almost certainly use a mixer/VFO or mixer/VXO using a ceramic resonator instead of a crystal. This will allow me to cover a useful part of the band on either CW or sideband and to provide CW offset easily. The DSB modulator will be a matched pair of diodes.

Quote of the decade

"If the climate was a bank they would have saved it", said Venezuelan President Hugo Chavez. "But it is not. And they have not"

See http://news.bbc.co.uk/1/hi/sci/tech/8423822.stm

20 Dec 2009

Pre-Christmas snow - improved 500kHz?

In the East of England we have had a treat these last few days: deep (for us) snow that is crisp and beautiful. We've had about 10cms here with a little more last night and everywhere is a picture. The attached photo is the lane immediately behind my QTH. This is a video of my house from the road in the snow.

Not sure if it is the improved ground conductivity, but my signals on 500kHz have been reported stronger these last few days.

Sunspots for Christmas please Santa

Judging by the last few days we are definitely seeing much increased solar activity at last. Today the sunspot count was an astounding 43, a figure not seen in a VERY long time. Is it too much to hope for some decent F2 openings on the higher HF bands over the Christmas and New Year? Whatever happens in the short term, there is now a high likelihood of a decent improvement in 10m propagation in 2010. Whoopee!

See http://www.solen.info/solar prepared by Jan Alvestad.

19 Dec 2009

500kHz WSPR - when I forgot the ATU!

Having used my 5m long vertical on 40m to work OY9R on QRP SSB this afternoon, I went back onto 500kHz WSPR but completely forgot to connect the ATU, so the antenna was connected directly to the transverter with no matching at all! I only realised this when I got a report from M0BMU some 20dB below that normally received (at -26dB S/N). I've since reconnected the 500kHz ATU and the 500kHz signal is back to normal. The IRF510 survived the gross mismatch.