18 Jan 2009

HUGE 160m 3el yagi antenna

Take a look at this antenna for 160m and 80m. It is the antenna used by OH8X and is absolutely massive.

This is certainly not my idea of ham radio, and the complete antithesis of QRP, but you have to take your hat off to these guys for the engineering of this monster beam which weighs tons. I wouldn't fancy scraping the ice off in mid-winter!

16 Jan 2009

Long-term HF deterioration?

Some time back I recall discussion about a theory that the ionosphere was not behaving nowadays as it was, say, 50 years ago. I'm not talking here about sunspot cycle issues but whether or not there are factors at work that mean HF comms today is more difficult than many years ago due to ionospheric structural changes. I'm also ignoring things like increased noise floors due to SMPSUs, lights etc.

Can anyone point me in the direction of any definitive references to this theory?

13 Jan 2009

AA1TJ's 1 transistor transceiver

Take a look at Mike's neat 1 transistor VXO controlled 80m 80mW transceiver, The Reggie, which uses a passive RX with the VXO acting as LO for a heterodyne mixer. He's worked some decent distances with this modest little rig. Mike has a great website with plenty of other fine ideas. The little Reggie circuit continues to evolve so keep checking back to his site.

http://mjrainey.googlepages.com/reggie

Update 19/1/09: Mike tells me he has measured the MDS as -87dBm (using a sig gen and a stepped attenuator/20dB pad) which is pretty remarkable for essentially a passive RX using a switching mixer. It implies Mike can hear around -90dBm clearly in his ST3 headphones.

12 Jan 2009

The spots return...

After weeks without sunspots the sun is showing signs of life again with solar flux levels around 70 (the highest for a year nearly) and sunspot numbers between 13-20 depending on who is doing the counting. Time will tell if this is the start of better things to come or another false dawn.

See http://www.solen.info/solar/

11 Jan 2009

Some off-air historical ham recordings

Thank you to those of you who have submitted ham audio links. Here are some for starters. I will add others if people let me have links.

http://files.myopera.com/davews/files/vp8.mp3 A recording of Bob McLeod VP8LP in Goose Green on the 20m amateur band on the evening of the Argentine invasion in the mid-1980s made by Dave Sergeant G3YMC.

http://files.myopera.com/davews/files/zl3gq.mp3 A short recording of a CW contact with Peter Watson ZL3GQ in Christchurch, NZ made by Dave Sergeant G3YMC on 4th October 1977 when using just 10W at Dave's end.

http://www.qsl.net/wa5iyx/ra/zk1aa69a.ra ZK1AA 6m keyer/beacon in 1969.

http://www.dxzone.com/catalog/Internet_and_Radio/Sounds/
has many different audio clips spanning many years and many bands.

10 Jan 2009

Off-air historical ham recordings

Looking around for a site which has off-air historical ham recordings I found http://www.dxzone.com/catalog/Internet_and_Radio/Sounds/ which has quite a lot.

Somewhere I have a reel-to-reel tape recording made off-air 42 years ago of G4PJ (Salcombe, Devon) and I also have a recording made at the peak of cycle 22 (I think) when I tuned across 10m SSB hearing stations from Europe, South America, the USA and ZD9 (Tristan) amongst others.

There is an excellent website for SW broadcast interval signals at
http://www.intervalsignals.net/ which I believe I've mentioned before.

QRP DXCC score box

I've added a 2009 DXCC "countries worked" box on the RHS of the blog so I can keep track of what I work on various bands. So far, the score is just 15 countries worked with best DX being the USA on 20m CW, but it is only mid-January. Last year the score was around 60 countries worked.

10m QSO (winter sporadic-E)

This morning I worked my first 10m station this year - 9A2009ST on 28.480MHz SSB using 10W to my wire halo antenna. He was also calling CQ on 28.22MHz CW. The signals were not strong but this is clearly a case of mid-winter sporadic-E.

This year my aim is 100 DXCC countries on 10m QRP, so this was number one. An hour later and I heard G0FWX about 20 miles away so gave him a call and got a 52 report.

So now 2 x DXCC countries in the log on 10m ....only 98 to go this year!

8 Jan 2009

Latest cycle 24 sunspot predictions

http://solarscience.msfc.nasa.gov/images/ssn_predict.txt has the latest (Jan 2009) predictions for the progress of Cycle 24 suggesting that by the end of this year we should be well on the "up" again with decent 15/12/10m conditions.

Having said that, we have had another extremely quiet period now for almost 6 weeks. Unless a few spots start to appear we may still be bumping along the bottom of the cycle still.

7 Jan 2009

QTH Locator with Google Maps

http://f6fvy.free.fr/qthLocator/fullScreen.php

This site has the useful ability to show QTH locator locations using Google maps. Enter the QTH locator and the map zooms to show where square actually is. You can also use it to find QTH locators in the first place and to work out distances.