K3 issue with Keying

[xxhound]

Has anyone had  problems with KEY CLICKS
with K3 on CW ????

Maybe  reloading firmware  is a good start ?
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Guy, K2AV]

Properly operated, the K3 has a pristine CW signal, using a number stream
from firmware to directly create the 15 KHz CW signal in the TX Digital to
Analog Converter.  Since all amplification/conversion is linear after that,
the same signal emerges properly shaped at the antenna jack.

The K3 has a constant and well deserved reputation for excellent CW that
does not bother people even just a few hundred Hz away.

There ARE ways to make a signal from a K3 or any other properly designed
transceiver have key clicks at the antenna.  They almost always involve an
amplifier.  Assuming (bad word) your power supply can actually supply a
stiff 13.8 volts, a K3 with key clicks barefoot has something busted and
needs to be sent back to Elecraft to get it diagnosed and repaired.

1) Probably the worst is to try and run break-in or semi-break-in into an
amplifier whose internal relays cannot follow the speed of the CW.  What
then happens is hot-switching, where the relays are making and breaking
contact during the sent signal.  The extreme sharp edges of the RF made by
the hard relay contacts of the amp will be heard well above and below
signal.  This is also capable of doing dreadful things to the amplifier,
including destroying tubes, pi-networks, bandswitches, relays, meters, tube
sockets, nearly anything except the input circuits and power supply.

2) The other biggie is to run 100 watts into anything other than a pair of
3-500Z or a 3CX1200A7 and let the amp ALC throttle back the K3 power on a
baud by baud basis.  This will generate clicks, because the ALC  *MUST*
quickly shut down power to protect tubes -- the pristine CW signal is being
chopped ASAP to keep from toasting grids and turning your expensive final
tubes into lamp fodder.  DO NOT use amp ALC to set levels.  Do that with the
K3 power knob to set the proper level, and set your ALC levels somewhat
above that ONLY to protect your tubes if you forget to back off going from
running 100 watts barefoot to needing 60 watts to drive an amp.

3) If you tune well off your antenna's resonance without retuning, that will
raise grid current, you will be operating your amp outside its linear zone.
 This will flat-top the signal, creating sharp edges to the CW envelope that
are not there at the K3 output.

4) Aside from using an amp improperly, an amp can have a range of problems
requiring repair or final replacement that will produce key clicks from a
perfect signal on its input.  These need to be separately diagnosed and
fixed on their own merit.

73, Guy.

On Fri, Mar 4, 2011 at 9:05 AM, JoshL <[hidden email]> wrote:

> Has anyone had  problems with KEY CLICKS
> with K3 on CW ????
>
> Maybe  reloading firmware  is a good start ?
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html