[Elecraft] K2 is break-in only on CW?? Part II

[Don Wilhelm]

Jay,

If you need to extend the dropout time to keep the relays held in longer, a
simple delay extender circuit can be added to the K2 amplifier keying line -
a 2 2N2222 darlington coupled transistors with 2 or 3 resistors, a large
capacitor and a diode will do the job nicely.

73,
Don W3FPR

"Life is what happens when you are making other plans"
(John Lennon wrote it in a book, Mike Cross used it in a song - I don't know
who was first)

----- Original Message ----- 
From: "Jerry Summerall" <k7yvz at interplus.net>
To: "Don Wilhelm" <w3fpr at arrl.net>; "Jay Kesterson" <k0gu at verinet.com>;
<elecraft at mailman.qth.net>
Sent: Sunday, June 06, 2004 9:31 AM
Subject: Re: [Elecraft] K2 is break-in only on CW?? Part II


> The 8R line delay is not long enough to hold the last one or two relays on
> my DEMI sequencers especially when running 15-20 WPM CW. I don't believe
it
> is hurting anything but I hate to hear the relays clicking continuously
> while operating. At the same time, after using QSK CW, going to semi break
> in is sort of annoying.
> ----- Original Message ----- 
> From: "Don Wilhelm" <w3fpr at isp.com>
> To: "Jay Kesterson" <k0gu at verinet.com>; <elecraft at mailman.qth.net>
> Sent: Saturday, June 05, 2004 4:25 PM
> Subject: Re: [Elecraft] K2 is break-in only on CW?? Part II
>
>
> > Jay and all,
> >
> > There certainly IS a line in the K2 that can be used for sequencing
> > switching of transverters and other external devices.  The 8R line
becomes
> > active about 20 ms before RF is presented at the antenna jack, and the
> > drop-out time can be adjusted via the K2 menu - so to my way of
thinking,
> > the needed sequencer is already built into the K2.
> >
> > The KPA100 amplifier keying output follows the state of this 8R line,
and
> > the signal is used in the K2 to Elecraft transverter connection (KIO2)
to
> > switch the Elecraft transverters.  For those who are driving
non-Elecraft
> > devices with the base K2 (QRP), I suggest you look carefully at the 'K2
> > External Power Amplifier Keying Circuit' shown on the Elecraft website -
> > Builder Resources area, then select Application Notes, Eric originally
> > designed it for use with an external amplifier, but can do the same job
> with
> > external transverter equipment.
> >
> > I believe that easy-to-build keying circuit will do the external
switching
> > job you need - OTOH, if your external devices need more than 15 to 20 ms
> to
> > become properly active, you may still be in trouble, but that IS a
> > relatively long time period, even for relay operation and you may have
to
> do
> > some work on the transverter end to make it switch faster.
> >
> > 73,
> > Don W3FPR
> >
> > "Life is what happens when you are making other plans"
> > (John Lennon wrote it in a book, Mike Cross used it in a song - I don't
> know
> > who was first)
> >
> > ----- Original Message ----- 
> >
> > >   Thanks for all for the replies to my question. My concern is using
the
> > > K2 with V/UHF transverters, amps and preamps (some mast mounted).
These
> > > are usually controlled with a sequencer that hard keys the radio last.
> > > In certain setups accidentally bumping the paddle and having the rig
> > > xmit could damage equipment down stream. I can use the PTT line from
the
> > > sequencer, that would normally be used for hard keying the rig, to key
a
> > > relay that doesn't allow CW to get to the K2 till all the up stream
> > > equipment is ready. However I use a foot switch and headset, that gets
> > > switched to three different rigs, on SSB. The footswitch is used to
turn
> > > on the sequencers during both SSB and CW operation.. On weak signal
VHF
> > > we often switch between SSB and CW. If I use PTT, from the sequencer,
on
> > > SSB I haven't figured out a way to easily (automatically) disable the
> > > SSB PTT line on the K2 when I switch to CW. Any ideas, beside
unplugging
> > > the mic connector or otherwise manually disabling the mic PTT line??
Is
> > > there some signal point inside the K2 that is active or grounded only
> > > during CW that could be used to possible drive a relay to disconnect
the
> > > SSB PPT line while in CW??  Or better ideas??
> > >
> >
> >
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