[WriteLog] Writelog, MMTTY Weird keying problem

[Timo Pohjola]

In CQ WW RTTY we used Writelog + MMTTY at OH1F.

During the contest we encountered a strange problem several times. When
S & P:ing sometimes the stations simply were not able to decode our
transmission. They (e.g. KH7X, EI4DW) did not copy our callsign "OH1F"
correct (it was always OH7.. OH8.. etc.).

In the monitor the transmission sounded OK.

I think some other stations had also this same problem, we were not able
to decode their signals though it sounded OK.

Any idea what was this problem? We used Writelog, MMTTY, FSK keying from
COM port, FT1000mp, 333&266MHz PCs.

73 Timo OH1MDR