Sunday, 2 February 2014

80m digimodes - PSK31 and WSPR

As part of a plan to try out WSPR on 2m soon, I tonight reinstalled the WSPR software, and have started it up, just in receive mode, on 80m. The reason for choosing 80m is that the radio and ATU were already set up there for PSK31, so it was just a quick turn of the big knob.

Just before downloading WSPR, I was watching the waterfall on FLDIGI, and spotted GB6WLB, the SOS Radio Week station from Walton-on-the-Naze RNLI station. As a very big fan of the RNLI's work (and having been one of the people who selected their Swissphone pagers for them!) I jumped on and worked them. I still havent quite got the hang of the macro buttons on the software!

With WSPR now downloaded and installed, I proceeded to try and get it working. After a few minutes head scratching I remembered that unlike most data modes, the waterfall is not dynamic, and I have to await the end of a decode period before it updates! This done, I could start trying to set the receive level. Strangely, no matter what mic gain I use on the soundcard, the indicator goes back to -30dB a few moments later. But, it is decoding successfully.

Theres me, smack bang in the middle of the UK. Once Im happy that alls well decoding, I might be tempted to set the radio to about 2w and Tx as well, see where I get.

The ultimate idea is to try WSPR on 2m using me trusty old Yaesu FT-290mk1. This is a venerable old bugger, but whether its frequency will be stable enough I dont know yet. I need to make up a mic lead to allow me to feed the PC audio into it before I can do much else. Also, a bit of a worry is that my halo antenna on the apex of the roof is fed by a long run of RG-58, not exactly the lowest loss feeder! I do have some unmeasured long lengths of RG-213, so I might ponder swapping the feeder at some point.

On the subject of antennas, yesterday at work during my break I made use of the Baseband desks toolkit, and fitted a crimp on BNC plug to the RG-174 coax of that little magmount that came with the DVB-T2 PCTV dongle, the element of which I had already swapped for the 2m/70cm dual band antenna from the old mini magmount I got off Richard. In case there was any impedance matching network to sort out, tonight I dismantled the old duff magmount to see what was inside

as can easily be seen, theres no matching network inside to worry about. What is worrying, is that the braid was just clamped between the magnet and the casing, hardly good VHF practice! But it does suggest that the rebuilt version should work ok, I will test it tomorrow, always assuming of course its not raining.

For now, im going to sit back, enjoy my well deserved two biscuits and glass of Aberlour, and watch the spots come in

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