The Problem of Two WSPR Frequencies on 80m

Considering that there is pretty much no chance of any 28 MHz propagation at night, I decided to set the radio on the 80m WSPR frequency for the last two nights.

On the evening of Tuesday 26th March 2019, I set the radio to 3.59260 MHz which is the frequency that I had written down in my own notes and the one I had used in the past. It seemed to work fine and I heard plenty of stations that evening and the following morning on 80m.

On the evening of Wednesday the 27th of March, I went to tune the radio to 80m again but this time, I noticed that the frequency on the WSJT-X programme was different, it was 3.56860 MHz.

I used the new frequency and this is what I heard overnight on 80m on the night of the 27th - 28th of March 2019...

Signals heard on 80m WSPR - night of 27th to 28th March 2019

Closer view of European stations

So it would seem that there are two WSPR frequencies on 80m and both are in use.

After doing a bit of research, it looks as if there was some issue with stations in Japan being able to use the old frequency of 3.59260 MHz. As a result, it was decided to change to a new frequency of 3.56860 MHz.

The problem is that not everyone has changed and the net result for the moment is that WSPR users on 80m are split over two frequencies which is a bit of a mess.

I would guess that over time, the new frequency of 3.56860 MHz will gradually replace the old one but it might take a while.

Addendum :
Which is most used? ...Old or New Frequency?

As an experiment, I listened to the two WSPR frequencies on Wednesday the 27th of March from 20:00 to 22:UTC to see which one had the most activity.

This was well after sunset and to get a fairer idea of activity, I listened to the new frequency for 30 minutes at 20:00 and 21:00. I listened to the old frequency for about 30 mins from 20:30 and 21:30.

The result was that I heard 113 WSPR transmissions on the new frequency and 99 on the old one. I'm sure if I listened again on another evening then I may get a sightly different result. That works out at 53% to 47%.

It's probably fair to say that the WSPR activity on 80m is pretty much split pretty evenly between the old and new frequencies at the moment.