[Elecraft] "Bug" for K2

[Mychael Morohovich]

Some months ago, Tim W3ZVT of "Sox Key" fame generously invited me over to
try out his extensive collection of bugs to give me a feel for what was out
there. I tried everything from Vibroplex to McElroy to SpeedX to GHD models,
with the latter really catching my fancy.

While the GHD with mechanical contacts was nothing to sneeze at (nor was the
fully-automatic bug!), I fell in love with the standard double paddle model
with the optical contacts. No contact bounce whatsoever, and the weighting
of the dits could be adjusted by moving the optical contact relative to the
"blinder" attached to the bug's pendulum. In other words, by adjusting the
period of time that the sensor is interrupted each cycle, you change the
length of the dits. If you have an ear for it, adjusting the weighting is
very easy.


While I find the optical contacts great, one drawback is that they require a
power source: anywhere from 9 vdc to 13 vdc has worked fine for me. At 9
volts I measured 5.4 mA draw. No big deal, but since the bug draws current
in order to affect a key-up condition, it will run down that 9 volt battery
if left hooked-up indefinitely. Furthermore, as you can no doubt deduce,
removing the power source while the key is attached and the rig powered up,
in effect closes the key. This necessitates that one also first remove the
key line. If you use a transformer power supply you probably won't worry
about any of this, but it is worth a mention nonetheless for those who rely
on battery for their DC needs.

Low speed of the stock model was around 18 wpm. Tim machined for me a
heavier weight that allows me to get down to 15 wpm, but attaching a croc
clip to the pendulum as Ron AC7AC has mentioned does roughly the same with
perhaps a little less panache <g>.

There was a mention in this thread about bugs possibly needing a reed type
relay in order to key the K2 correctly. I haven't found this to be true with
my setup, but (with the optical sensors) if you plan to key anything with a
tube final you will need to use a relay- which isn't a bad idea anyway.


Mychael AA3WF
K2 #1025