Twin tee oscillator

A twin-tee audio oscillator is a very useful item to have around the shack. Looking around the net for suitable circuit values yesterday I came across this page by G0XAN http://homepage.ntlworld.com/g0xan/twin-t.htm

I shall be using one this week with my CW keyer to send slow CW (QRSS) on 1.2kHz and 8.97kHz. For very slow CW I'll need a much more stable oscillator probably a crystal and digital divider, although many on the "Dreamers Band" are using a DDS source.

A very young trainee engineer?

This afternoon I had some "help" from a budding radio engineer aged 2.5yrs - my young grandson. We were in the lab mending a toy fire engine (see picture) but he was more interested in twiddling the audio generator and listening to the tones and watching these on the oscilloscope. To see the video go to http://www.youtube.com/watch?v=tRwaT9s6ZHM

Latest NOAA sunspot predictions for cycle 24

The very latest sunspot predictions from NOAA for cycle 24 make rather depressing reading showing a 95% probability of a peak smoothed sunspot number of just 91.8 in June 2013. By this autumn we should see counts in the mid 40s and the following autumn around 75.  10m transatlantic openings should be common again from this autumn, but the low sunspot peak suggests 6m openings will be much less frequent than in recent cycles. So, in my lifetime it is unlikely I'll ever see again the halcyon days of the peak of 1957-9 when conditions were remarkable.

Croatia on 500kHz

9A5K has been granted an experimental licence to operate on 493-510kHz as well as on the 5MHz band from June 10th.

Good Es today

Only had a brief chance to listen on 10m and 6m today but both bands were busy with Es signals from right across Europe. The season is well and truly underway now. A brief listen on 2m did not result in any DX being heard.

SAQ (17.2kHz) CW VLF transmission Sunday July 4th

There will be a further transmission from the historic VLF transmitter at Grimeton, Sweden on July 4th at 0900 and 1200 UTC on 17.2kHz CW with tune-up 30 minutes before each transmission. 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

SE-430 16 ROLFSTORP, SWEDEN

See: www.alexander.n.se

SRC X80 antenna has arrived

Well, I'm very impressed with how quickly Snowdonia Radio Company despatched my X80 multi-band Rybakov HF vertical: it arrived on my doorstep early this morning only a few days after ordering it. I shall not be able to erect it until next week though as my little grandson is staying with us until Monday. All being well, I'll erect it on Tuesday.

San Marino on 4m

The San Marino authorities have authorised 4m operation (100W max) until the Oct 31st 2010, on 70-70.5 MHz. T77C and others will operate from San Marino 19-20 June.

PLT-Interference Range Contest

The EMCIA have announced a contest to identify the interference range of Power Line Telecommunications - otherwise known as PLC or BPL.  See http://www.emcia.org/documents/News/Rules.pdf

Useful multi-band HF vertical

The Snowdonia Radio Company is offering the SRC X80, a 5.8m long multi-band HF vertical matched via a 9:1 unun matching box. This sells for just £47, which is excellent value compared with similar offerings from the Japanese manufacturers. Such Rybakov antennas offer a decent match, easily brought to 1:1 VSWR using an auto ATU, on the higher HF bands. On the higher bands performance is quite acceptable considering the compromise in size. In the latest edition of PW Magazine G6MXL reports working plenty of DX with 50-100W using one.