[Elecraft] CW PTT

[W3FPR - Don Wilhelm]

Bill,

You can extend the T/R dropout delay in the K2 menu (T-R Hold or something
similar if I recall properly).  There is no other provision in the K2 menu
that indicates "Amp in-line", and no signal provided to the K2 to indicate
the presence of an amplifier.

With a 15 ms pull-in relay, I can see no reason why that amplifier cannot do
QSK (unless you object to the sound of relays clicking, and the only
solution to that is electronic T-R switching).  Of course, that does depend
on your definition of QSK - if you are looking to hear between dots at 30
wpm, then it is not likely, but to hear between characters at 25 wpm should
be 'do-able'.

You may find that changing the menu to INP Hand and holding the key down
will provide a more constant output level than using TUNE - what you are
encountering is the K2 ALC is attempting to keep the output constant.  If
you use the 10 watt level to tune your amplifier, you will find the leveling
resolution to be much finer (more constant level).

73,
Don W3FPR

> -----Original Message-----

> On Aug 24, 2005, at 8:49 AM, W3FPR - Don Wilhelm wrote:
>
> > The K2 produces RF about 15 to 20 ms after the KPA100 Amp Keying
> > output goes
> > low, so if an amplifier can be ready to accept RF input properly
> > within that
> > time period, it is fast enough to follow the K2.
>
> Great. I just bought an AL-80A from an estate sale and was wondering
> if the K2 would be hot-switching. The specs indicate a 15 ms relay
> changeover time, so that should work great with the K2.
>
> There are only two issues with the K2/100 and the amplifier: 1) the T-
> R timing ought to change when using the amp, since it can't do QSK.
> 2) the K2/100 power output seems to "dither" by about 5-9 watts
> depending on the power setting. This makes it very hard to tune the
> amp, since the K2 power output jumps around so much.
>
> I realise there's a fix for the latter, by increasing the value of a
> 270 ohm resistor in the ALC chain.
>
> Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
> Quote: "Not within a thousand years will man ever fly!"
>              -- Wilbur Wright, 1901
>
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