"the keyer buffer stayed full for 4s" and nothing keyed, on a rig whose CAT is
working. The buffer was not full: the check demanded the reply be exactly "KY0;"
with the digit at byte 2, so anything the FTDX10 phrases differently — a space
before the digit, another command's reply arriving first — read as "still full"
on every poll until the deadline.
The test is now asymmetric on purpose: only a clear "1" holds the send back.
Anything unrecognised goes ahead. Refusing to transmit because a status line was
phrased unexpectedly is the worse failure — the operator gets silence with no
explanation, where at worst sending early truncates a long message, which the
chunk loop then recovers from.
The reply is also logged once per run, since we have no verified sample of it —
that line is what turns the next surprise into a fact instead of a theory.
The radio has a keyer and a command to feed it (KY), so an FTDX10 needs no
WinKeyer and no second cable, exactly as the Icom CI-V and Flex CWX engines
already do. The rig keys with its own timing, which is why the spacing is right
where a PC keying a line through USB latency drifts.
Text is filtered to what the keyer can actually send: an unsupported byte does
not produce an error on a Yaesu, it can abort the whole buffer, so the rest of a
macro would vanish silently. It is then fed in 24-character pieces, waiting for
room between them — the rig DROPS what does not fit, again with no error, so a
contest CQ would lose its tail.
STOP is the honest gap. Yaesu documents no buffer-clear, so it drops the
transmitter (TX0) instead: nothing queued reaches the air, which is what Escape
means to an operator. It deliberately does NOT send "KY0;" — a plausible-looking
clear that the rig would read as the CHARACTER zero and transmit.
A test caught a real one on the way: tabs and newlines were dropped as
"unsupported", gluing the words either side together, so a macro written on two
lines went out as CQCQ. Whitespace now becomes a word gap before filtering.
Settings warn when the Yaesu keyer is selected without the Yaesu CAT backend —
otherwise it simply never keys, with nothing on screen saying why.
Send path follows the CAT reference and how Hamlib drives these rigs; NOT yet
verified on the air.