Thursday, 22 March 2012

Keep Calm and Work Some DX

This is a bit of fun. It is a take on the British WW2 "Keep Calm and Carry On" posters.

"Keep Calm and Carry On" was a propaganda poster produced by the British government in 1939 during the beginning of the Second World War, intended to raise the morale of the British public in the event of invasion.

Seeing only limited distribution, it was little known.

There were only two known surviving examples of the poster outside government archives until a collection of about 20 originals was brought in to the Antiques Roadshow in 2012 by the daughter of an ex-Royal Observer Corps member.

But now you can wear your own "Keep Calm and Work Some DX" T-shirt, baseball cap or own a mouse mat thanks to Cafe Press.


Tuesday, 6 March 2012

Using MMANA-GAL for antenna modelling

I gave a talk on antenna modelling using the free MMANA-GAL software at my local Amateur Radio Club. It looks at what MMANA-GAL is, how to use it and then a number of different applications.

Some of these are useful and surprising - like how to optimise a 40m off centre fed dipole (Windom) so that you can get 15m. And how mounting an antenna as an inverted V can seriously change its radation pattern or number of bands available.

It also asks the question is the G5RV really a good multiband antenna? Why was my W3EDP end fed better to the south-east and south west and rotten to the north. And does the DL7PE Microvert radiate off its feeder?

Download the presentation in PDF format with the notes included (8.8Mb).

Note: I have also made available a Zip file with some .maa files including the End fed Half Wave, Rybakov vertical, DL7PE Microvert, 80cm magnetic loop, 65ft Inverted L, EH antenna, 20-15-10m trap dipole, 80m OCFD (Windom) and an experimental W5GI mystery antenna file. Download the MMANA-GAL antenna files.