Pushing WSPR

I'm sitting on 40 metres tonight. It's been a good afternoon - I have had a 2-way with VK7BO in Hobart, Tasmania, and several 2-ways across to the States. But the band has done its usual metamorphosis as the sun sets, and I am now looking at a solitary U-shaped plot.

His frequency is varying.There are three on the plot. The first looks like an abort. The second curls up at the end, and the third is much more U-shaped. All three are quite strong. It looks as if the power could be decreased to help with the frequency stability. WSPR is an incredibly low power mode - it will decode very weak signals. But they do need to be stable, with next to no drift.

But, all said, I am pleased with 40m/5W/LW tonight:

And even 80m has one or two interesting facets:

A real QSO with 5Z4/VK1UN would be rather tasty. That plot isn't as good as it seems. I heard him, he didn't hear me.

QRO WSPR ?

Found on the internet:

High power WSPR has caused feedback problems Now turned the wick down to 5 watts. Already been picked up in Germany Lots of noise from switch mode PSUs.

Dear fellow ham,
WSPR stands for Weak Signal Propagation Reporter. It's used with weak signals. With WSPR, you get a long, long way for not very much power. And not very much antenna. String a bit of wire into your garden, set to 500mW and, on say 10 metres at the moment, you will make Australia at the right time of day (morning), and the States in the afternoon.

I hardly ever use more than 1W. I occasionally use 5W because the Long Wire I have won't tune on 160m easily. I use it connected to another rig, which won't go below 5W.

Your Switch mode noise doesn't mean you need to TX with more power. The other end won't see your switch mode PSUs - only theirs. If they're lucky, and they have a low noise floor, then they'll hear your 500mW.

Switch mode noise is a problem for your reception, clearly.

But, serious plea, don't go QRO with WSPR. JT65-HF has, to a certain extent, been spoiled by QRO operators who have discovered that by answering a CQ at high power they can drown out the rest of us. It's disappointing. And it's great to hear the bands when they are quiet and the QRP DX comes back above the noise floor.

Good luck with the noise. And remember, 500mW is plenty.

VHF JT65

Tim, G4VXE, and I had a short session this afternoon with JT65 on 2m, using the JT65-HF program, just because we both had it configured.

We started out on 144.165.000 using 10W each, into a collinear at each end. My collinear, just so you get the picture, is screwed to a shed wall. I can touch the bottom of it. The copy was, by HF standards, astoundingly easy - we exchanged -05 (him at my end) and -09. Tim dropped to 1W, and I still had very easy copy at this end, well above the noise floor.

A back of an envelope calculation suggested that we'd hit -24dB at 150mW. This is over 140 km, with "poor" aerials. I can't get that low with any of my kit - pout!

There is a lot of mileage to JT65 and its siblings on VHF. I'd like to try this on 23cm