[TenTec] OMNI 6+ and Iambic (Different issues)

[Ben K8DIT]

I have a question for the group.

Listening to QRQ from time to time I notice that many ops speed up briefly,
especially when sending 599, then slow back down. How is this done? One
notices it more in pileups and/or contests, but is also heard in regular
qsos from time to time.
My guess is that its a memory button on a keyer, is this correct? But it
sounds seemless and one would think that the sender would mistake one memory
button for another from time to time. So straighten me out here. If you
turned the speed up on any keyer you would overshoot the speed and send
gibberish, but whenever you hear the sudden speedup, it seems smooth and
very nice.