Sunday, 21 August 2011

Shush! You only need to whisper......

Well hello. Where have I been? What have I been up to?

It has been a hectic few weeks. The shop has been incredibly busy, and that has taken up so much of my time and energy that I haven't been doing much else to be honest. Working 6 days a week, being crazily busy, and struggling to keep my head around everything has seen me feeling very tired. Not physically tired, but mentally exhausted.

I don't know if it is what you would expect as you get older, but my brain simply doesn't work as quickly as it used to. It's a bit like an old pc that could do with a bit more RAM and having the operating system re-installed! Mind you, if that were possible, I would much rather they installed OS-X Snow Leopard rather than Windowz. ;-)

I have been doing some more of the cross stitch, although not as much as I would have liked to. I found it very hard to give it the required concentration, and when I did pick it up found myself either making silly mistakes, or rechecking what I was about to do was right so many times that I didn't get much done.

I have now finished the sky and have started on the lighthouse. I'm pleased with the way it is coming along, I always knew it was going to be a long project, but ultimately worthwhile. By the way, the vertical orange stitching is just temporary to help me work out what goes where!

The other thing I have been doing is playing radio. I have discovered some of the new data modes being used on the ham bands.

Many years ago, several friends and I regularly sent computer programs and pictures via VHF ham radio bands. We discovered a few new techniques between us and had an awful lot of fun.

Here we are a couple of decades later, and things have progressed almost beyond belief. Some of the newer data modes leave me shaking my head and my jaw on the floor. The two in particular that have tickled my fancy are PSK31 and WSPR, which is also known as "whisper".

The thing that has particularly impressed me with these is just how little power needs to be used to transmit these modes. Low power operation is known as QRP, this being judged as being 5 watts or less. When you get into the realms of 1 watt or less, it is known as QRPp. Most ham radio sets have 100 watts of transmit power, and a lot of radio amateurs around the world use an amplifier to take their power up to 1000 watts.

To discover that there are people around the world using these new data modes with very tiny transmit power is incredible. Because WSPR and PSK31 transmit using very slow data rates and are decoded by computer software, it means that the received signals can be virtually inaudible to the human ear and they will still get through, making them ideal for low power operation.

PSK31 is a "live" mode where you type to one another, whereas WSPR is an automatic mode, and this has really gotten my interest. You set your radio to one of the designated frequencies, and leave the software running on the computer. The audio from the radio is fed into the sound card on the computer. The only other thing you need to do is make sure that the clock on the computer is SPOT on time. More than a couple of seconds out can mean the whole thing won't work.

Signals received are decoded by the computer and displayed on the screen, with the call sign, locator and transmit power being used by that station. These are then uploaded to the WhisperNet web site for everyone to see. The idea being that if you have been transmitting you can see who has heard you and their distance from you.

Signals being sent with miniscule transmit power can go a surprisingly long way. I have heard stations all over Europe using powers between 5 watts and 0.02 watts. I have even heard a station in America who was using only a few watts.

The other nice thing about this is that you can leave it to get on with it unattended, and the last couple of Sunday's have seen me letting the radio station receive the whisper signals and upload the results while i have been getting on with other things. Incredible!

The person i have mostly thank for getting me interested in WSPR is Julian Moss, G4ILO. I discovered his excellent blog while Googling a few weeks ago. It is well worth a visit if you are interested in amateur radio - G4ILO's Blog. He has a few articles all about WSPR, and this is how i first discovered it - thanks Julian!

Julian has also recently started another blog called One Foot In The Grave, this deals with his life since he was diagnosed with a brain tumour. It is both heart rending and witty - i urge you to check it out. We all wish him well.

The other website that is an absolute MUST is WSPRNet, where you will find out more about Whisper, what it is, how it works, and more importantly WHY it is being used. It is kind of like taking part in a huge worldwide science project.

I'm off the the Rugby Radio Society's annual "radio show" in Princethorpe in a bit, so i will sign off for now.

- Posted using BlogPress from my iPad

No comments:

Post a Comment