9 Jun 2010

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

7 Jun 2010

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.

5 Jun 2010

4m beacon in the USA

This news is about 4 weeks old, but I missed it!

A new 70.005MHz (4m) beacon  WE9XFT is operational from Virginia, USA, FM07fm. Callsign and a short message is sent continously in CW at 18 WPM/90 LPM. It's a radio science beacon for sporadic-E propagation purposes. ERP is 3 kW from a 3 el. yagi at 60°, i.e. Europe. The beacon will run 24/7 until Sept 1st. The beacon is non-amateur and sadly no 2-way QSOs can take place.  Reports via e-mail to WA1ZMS.

2-way QSO on the 8.97kHz "Dreamers Band"

DJ2LF and DF6NM held what was probably the first two-way contact on 8.97 kHz. The distance between them was 20.2 km, well outside the reactive near field zone (λ/2π = 5.3 km). In each case the radiated power was about 5uW. They used a special QSO procedure using dual frequencies. Congratulations to both stations.

4 Jun 2010

Noctilucent Clouds and microwave DX?

Noctilucent, very high altitude, night time visible, clouds are becoming more common and at lower latitudes. This may be a result of climate change. One phenomenon associated with these is strong microwave radar echoes, raising the possibilty of very long distance DX by reflection from these on bands like 10GHz. This is an area ripe for experimentation but I am unaware of ANY groups anywhere investigating this exciting new propagation mode.

There is a  link between noctilucent clouds and the solar cycle with NLC activity peaking just after solar minimum, possibly because low solar activity allows the upper atmosphere to cool, promoting the growth of ice crystals that make up the clouds.  See http://spaceweather.com/

2 Jun 2010

SWLing in the 1960s

Back in 1961/62, when I first got interested in shortwave listening, a friend of mine and I had an intercom across our back gardens with a long piece of twin flex and a couple of DLR5 headsets. Now my friend's dad was a bank manager and he was "rich". Paul's dad bought him a Perdio 102 multiband receiver which made me green with envy! So, late at night, under the bedclothes, we'd both share listening on the Perdio102: Paul would put it to listen on 2.182MHz (the trawler band calling frequency) and we'd often hear an emergency and the local lifeboat being called out. We'd listen for hours. On this same receiver I recall being amazed at hearing South America hams on AM. We both became hooked and not many years later got our licences. See also the radio museum pages at http://www.radiomuseum.org/r/perdio_multiband_102.html

HF transceiver ideas site

Vanyi Istvan Vanyi YO5OFJ has an excellent website with links to a whole list of HF transceiver designs from around the world. Most are QRP designs with links to the originating sites.

Amateur Radio Wiki

Not sure how I'd managed to miss this amateur radio wiki site before, but it looks worthwhile bookmarking.  Being a wiki, it allows users to add or modify content in a similar way to Wikipedia. It has some useful links and data.

Elecraft K1 stand idea

Someone was asking about a stand to angle the Elecraft K1 transceiver at a suitable angle on the operating desk. A commercial version is available, but I found a simpler solution: two large rubber feet at the front and two small ones at the back. This angles the rig up about 10-20 degrees and is perfect for operating on a desk.