22 Jun 2012

6m WSPR and Doppler shift

Note Doppler on signals at 1742z
This evening some very strong signals have been coming in from North Africa on 6m by Es. CN8LI has been coming through on WSPR for a few hours with some people receiving him at +12dB S/N. What is interesting is the amount of Doppler on his signal at times. Also, several other signals coming through with up to 40Hz of shift over the 2 minute WSPR slot making decoding impossible. Some of this will be aircraft reflection, but some may be due to fast moving layers of ionisation in the E layer. At least with the WSPR screen such effects can be seen.

21 Jun 2012

Digital QST

Although not (yet) an ARRL member I am tempted join to get the new digital version of QST magazine. A sample of this new digital version is available from the ARRL website.

QST has been a very useful source of data going back to around 1916. I well remember thumbing through the copy in Plymouth library when attending  RAE lessons at Plymouth Tech way back in 1966.

Rigol test equipment

The Rigol Spectrum analyser at £895 plus VAT
In recent weeks I've seen several adverts on the ARRL website (I had a 30 day free trial) for test equipment made by a company called Rigol. In the UK they sell a well specified spectrum analyser for £895 plus VAT, which looks an incredible bargain for such an instrument. They also do a range of other pieces of test equipment such as scopes, waveform generators and power supplies. Although £895 is a bit out of my price range, I wonder if anyone reading this has any experience of this supplier's kit? If so, what is it like in terms of quality and reliability? If one was running a small RF design business one could set up a small, well equipped lab for a few thousand pounds with all new gear from this supplier. How do they do it?

SAQ transmission on 17.2kHz on July 1st

From the SAQ website:
Transmissions on Alexanderson Day
We plan for transmissions on Alexanderson Day Sunday 1st July. If we are allowed to use the antenna we start the machine transmitter at 8.30 UTC and a message is sent at 9.00 UTC. Second start of the transmitter at 11.30 UTC and a message is sent at 12.00 UTC. The frequency is 17.2 kHz CW.
 QSL-reports are kindly received:
 QSL reports can be given via:
- E-mail to: info@alexander.n.se
- or fax to: +46-340-674195
- or via SM bureau
- or direct by mail to: Alexander - Grimeton Veteranradios Vaenner, Radiostationen, Grimeton 72, S-432 98 Grimeton, SWEDEN
Note: SAQ is a member of the Swedish Amateur Association (SSA) and "QSL via bureau" is OK.

20 Jun 2012

ISS Flash Project

Guido PE1NNZ has sent me this interesting link about a recent experiment with the International Space Station using optical frequencies. See http://www.cqdx.ru/ham/ham_radio/iss-flash-project/ .

Back home again and the 472kHz transverter

Icefield Parkway, Alberta
After nearly a couple of astounding weeks in British Columbia and Alberta, Canada my wife and I are now back home. The scenery and wildlife were just amazing, especially the bears like the one below seen just a few metres away from us.  Although I only managed about an hour of shallow sleep on the plane back from Calgary last night I decided it was better to fight the jet-lag and get on with some chores rather than crash out and wake at 2am tomorrow.

One of the 8 black bears we encountered - this one VERY closely
Once the lawns have been trimmed and the hedge cut, I've decided to crack on with the design of a new transverter for 472-479kHz as the next project. Already there is activity from Germany and there are a number of NDB beacons to allow the receiver part to be checked. Jan 1st 2013 (the likely date of release in the UK) will arrive far too soon.

I am trying to decide on the choice of IF as I want to use an unmodified FT817. 28MHz will allow 472-479kHz to appear "in-band", but at 28MHz the start-up drift as the LO settles will still be some tens of Hertz. This hasn't proved problematic with WSPR, so guess this is my choice. At least the dial will directly read the "right" frequency e.g. 28.477kHz will correspond to 477kHz.

In view of the picture above, I am not sure what power the transverter will use bear-foot (sorry, weak joke).


18 Jun 2012

Knife Edge Refraction at VHF

Currently I am sitting in a log cabin (with a log fire) surrounded by snow capped mountain peaks wondering how 2m propagation would be from here. Sharp mountains often allow good propagation into screened valleys by refraction over the peaks sometimes with strong signals. Unfortunately I have no ham gear (apart from Echolink) to try it. Instead I am just enjoying the views. 10cm snow forecast tomorrow here, HI.

15 Jun 2012

Canadian Rockies

For the last few days I've been in the Canadian Rockies. The scenery is truly the very best I've seen (inland) anywhere on Earth. The 300km drive today from Banff to Jasper had snow capped mountains and azure blue lakes and rivers all the way. Only seen 1 HF antenna so far and that was from the Rocky Mountaineer train from Vancouver to Banff.

14 Jun 2012

Germany gets 472-479kHz

Surprisingly, news on the wires today that German amateurs have been granted early access to the new MF allocation. I wonder if OFCOM will release it early too?

9 Jun 2012

"LF Today" RSGB book on special offer

This excellent introduction to LF/MF amateur radio is available from the RSGB bookshop at just £7.99 and I can recommend it. It helped me a lot when I started and still gets referred to regularly.