On the 26th of April 2019, I saw the signal again while the band was open to South America. Note that the trace shows KI5BLU in Texas (locator square EM12). Note that I have Puerto Rico marked ...more later.
This is the traffic that I recorded on FT8 which shows KI5BLU working Ireland, Wales, England and Germany on 28 MHz...
160630 -1 -0.1 1058 ~ EI8GS KI5BLU EM12
160645 16 -0.3 1224 ~ KI5BLU EI8GS -01
160700 -2 -0.1 1056 ~ EI8GS KI5BLU R-11
160715 17 -0.3 1224 ~ KI5BLU EI8GS RR73
160730 1 -0.1 1055 ~ EI8GS KI5BLU 73
160930 -23 -0.1 1431 ~ KI5BLU MW0PPM R+03
161000 -18 -0.1 1431 ~ KI5BLU MW0PPM 73
161530 -14 0.1 1837 ~ KI5BLU G3ZQH IO92
161630 -12 0.1 1835 ~ KI5BLU G3ZQH R-01
161700 -14 0.1 1838 ~ KI5BLU G3ZQH R-03
161730 -15 0.1 1838 ~ KI5BLU G3ZQH R-03
161800 -15 0.1 1838 ~ KI5BLU G3ZQH 73
163645 -7 0.1 924 ~ DK4CF KI5BLU EM12
164400 -7 0.1 754 ~ <...> KI5BLU EM12
Suspicious...
If this was 14 MHz or even 21 MHz, I would have thought nothing of it. But this was April at the bottom of the sunspot cycle. East-West multi-hop Sporadic-E from Ireland to Texas on 28 MHz would be unusual this early in the season.
I then checked on PSKReporter to see who was hearing KI5BLU over a three hour period...
I then selected several of those... AM70E in Spain, G4HZW, G0LUJ, 2E0XXO, G8IXN and G7KFQ in England, MU0WLV in Guernsey, EI8GS in Ireland and F5OIH in France. I then checked what they had heard over a six hour period.
All nine stations as well as myself had heard KI5BLU but had not heard a single other station on FT8 on 28 MHz from the USA.
It's safe to say that KI5BLU was not transmitting from EM12 in Texas.
Initially I thought he was using a remote station as suggested by his QRZ page.... " Elecraft K3-mini for remotehamradio.com"
After a second search on Google, I found this...
KP4/KI5BLU - Palmas - Puerto Rico 04-22-2019
Thomas, KI5BLU will be active as KP4/KI5BLU from Palmas, Puerto Rico, IOTA NA - 099.
He will operate on HF Bands. QSL via KI5BLU, LOTW, eQSL.
Link
This is what confuses people into believing the band is open to the USA when it's obviously not.