Tuesday, 1 August 2017

New FT8 digital mode

I haven't been on air much lately due to poor HF band conditions, so thought I'd get on air using  digital mode, as this will get through when bands are not too good. After reading some blogs decided to try the new digital mode, FT8. This is a lot faster to use compared to JT65, instead of waiting 60 seconds per over it transmits an over in 15 seconds. This makes it good for modes such as sporadic e where there is rapid QSB. The downside to overs speed is a drop in sensitivity, only able to decode down to around -20db, but this is good enough for contacts.

The software is still in beta and can be downloaded from Joe Taylor K1JTs website at https://physics.princeton.edu/pulsar/k1jt/wsjtx.html It was v1.8.0-rc1 when I downloaded it.

Install was fairly easy. I needed to update JTAlert as well to the latest version, and also edit a couple of config files in my logging program Log4OM to include this new mode.

I started on 80m, as this is fairly quiet and not much range, mainly around VK, so wouldn't make a spectacle of myself testing it out. Note the FT8 working frequencies are 2 Khz down from the JT65 working frequencies. The software tunes to this for you.

Spotted a CQ call by VK4AAN, Alan in Stanthorpe. He was strong, -01 so gave him a call, by clicking on his spot on the waterfall and waiting for his CQ to end and hitting the Enable TX button.

Once he answered my call the software takes over and controls the QSO. Usual swapping of reports, RRR and 73s exchanged. This was a strange experience, a computer controlled QSO!
Screenshot of the QSO

I checked after on PSKReporter, he was the only station to hear me. There is not much digital activity on 80m as most hams tend to head to 40m for DX. A pity as it can be a good DX band, opening up to the USA later in the evening here.

As a bit more confident I changed to the main evening DX band, 40m. Plenty of signals on here from VK, Asia and the USA. Tried a call to N6QQ John in CA. It took a few goes to get heard above other USA stations calling him as well, but eventually he came back to me Screenshot of the QSO

Checked PSK reporter, seemed to be getting out okay to several parts of the USA. Running around 30w from my IC-7300.

FT8 contacts logged to eQSL okay. LOTW is still to be updated, so will wait for this new mode to be added in before uploading.

A fun mode that will be good when bands are poor... Could even be used for SOTA or parks activations with the right location and equipment. Would need a laptop with time sync to an internet connection.

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