A FT-726R hand keyed with dots on 144 MHz.
Strong keying clicks are present over more than 100kHz bandwidth.
The serial number is 3H030740.
Time domain graph corresponding to the above spectrum.
The white track is amplitude while the red track is frequency.
At this slow speed the cause of the keying clicks is not obvious.
The figures below show this time domain function in an expanded
The first key-down.
The first key-up. Does not look nice, the reason is unknown.
The second key-down. Seems like ALC/TGC has turned down the
gain in a keyed stage so the output amplitude is not proportional
to the keying voltage. The (hopefully) soft start of the keying
waveform does not give any soft rise of the output amplitude, the
output seems to start very abruptly when the keying waveform
has risen substantially.
Note that the transmitter switches on and off with a nearly
20 millisecond margin.
There is plenty of time to allow the amplitude to rise earlier and
decay slower by not blocking the keyed amplifiers so hard.
This rig needs a modification to be acceptable on CW.