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Haunted K2

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Dave Sublette

Haunted K2

If this is a duplicate, I appologize, but I posted it 18 hours ago and
it hasn't appeared. Is there some delay built into this relector??

Good afternoon,

Now that I have your attention, I don't really think that my K2 is
haunted, but it does seem to want to tune itself.

As I tune the knob up and down the bands and come to the frequency that
I want to listen or transmit on, I stop turning the knob and I take my
hand off. The knob is fully stopped when I do this. As I watch the
readout after taking my hand off, the frequency starts to change slowly,
sometimes adding (or subtracting) as much as 80 hz to the frequency at
which I stopped the knob. The knob is actually turning by itself. It
may go either direction and seems not to be correlated to whichever
direction of rotation I was using when I stopped turning.

I have been using the K2 regularly on the HF bands only for the past few
weeks. Since building the unit last spring, I have used it mainly as an
IF rig on the microwave bands. Until the last day or two, I haven't
noticed the "self tuning" feature.

Perhaps this phenominom has been previously noted and a fix found. I
cheerfully admit that I haven't done any research in the Elecraft Archives.

So....what say ye about this?

Dave, K4TO

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Mark J. Schreiner

Re: Haunted K2

Hi Dave,

Check out the K2 manual, page 32, right hand column. Sounds like you need to loosen the set screws on the knob and push it in a bit tighter against the felt washer and then retighten the set screws. The felt washer acts as a friction brake and the amount of "braking force" depends on how much pressure is applied between the knob and the felt pad.

I've found that a mobile rig that I have which may have a similar construction the knob spins much more freely during hot summertime temperatures while in the winter it seems quite a bit more stiff.

73,

Mark, NK8Q
K2 #4786

>From: Dave Sublette <[hidden email]>
>Date: Wed Jan 04 08:39:25 CST 2006
>To: Elecraft <[hidden email]>
>Subject: [Elecraft] Haunted K2

>If this is a duplicate, I appologize, but I posted it 18 hours ago and
>it hasn't appeared. Is there some delay built into this relector??
>
>
>
>Good afternoon,
>
>Now that I have your attention, I don't really think that my K2 is
>haunted, but it does seem to want to tune itself.
>
>As I tune the knob up and down the bands and come to the frequency that
>I want to listen or transmit on, I stop turning the knob and I take my
>hand off. The knob is fully stopped when I do this. As I watch the
>readout after taking my hand off, the frequency starts to change slowly,
>sometimes adding (or subtracting) as much as 80 hz to the frequency at
>which I stopped the knob. The knob is actually turning by itself. It
>may go either direction and seems not to be correlated to whichever
>direction of rotation I was using when I stopped turning.
>
>I have been using the K2 regularly on the HF bands only for the past few
>weeks. Since building the unit last spring, I have used it mainly as an
>IF rig on the microwave bands. Until the last day or two, I haven't
>noticed the "self tuning" feature.
>
>Perhaps this phenominom has been previously noted and a fix found. I
>cheerfully admit that I haven't done any research in the Elecraft Archives.
>
>So....what say ye about this?
>
>Dave, K4TO
>
>_______________________________________________
>Elecraft mailing list
>Post to: [hidden email]
>You must be a subscriber to post to the list.
>Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
>Help: http://mailman.qth.net/subscribers.htm
>Elecraft web page: http://www.elecraft.com

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Don Wilhelm-3

RE: Haunted K2

In reply to this post by Dave Sublette

Dave,

Easy fix - just loosen the screws on the VFO knob and move it back a bit to
create more drag on the knob. Be certain the felt washer is in place, that
is the only thing that creates the drag - adjust the knob position on the
shaft until the drag is right for your taste. If you initially adjusted the
drag for a 'light touch', the felt washer may have compressed a bit and your
current drag is not sufficient to hold the knob in position.

As a note for those with older K2s, I have found that the felt washer does
compress and wear out after a long while, so for those with a similar
problem, you may want to consider replacing it if the range of drag
adjustment is not to your liking.

73,
Don W3FPR

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

>
> Good afternoon,
>
> Now that I have your attention, I don't really think that my K2 is
> haunted, but it does seem to want to tune itself.
>
> As I tune the knob up and down the bands and come to the frequency that
> I want to listen or transmit on, I stop turning the knob and I take my
> hand off. The knob is fully stopped when I do this. As I watch the
> readout after taking my hand off, the frequency starts to change slowly,
> sometimes adding (or subtracting) as much as 80 hz to the frequency at
> which I stopped the knob. The knob is actually turning by itself. It
> may go either direction and seems not to be correlated to whichever
> direction of rotation I was using when I stopped turning.
>
> I have been using the K2 regularly on the HF bands only for the past few
> weeks. Since building the unit last spring, I have used it mainly as an
> IF rig on the microwave bands. Until the last day or two, I haven't
> noticed the "self tuning" feature.
>
> Perhaps this phenominom has been previously noted and a fix found. I
> cheerfully admit that I haven't done any research in the Elecraft
> Archives.
>
> So....what say ye about this?
>
> Dave, K4TO
>

Dave Sublette

Re: Haunted K2

In reply to this post by Dave Sublette

Thanks to all who responded. The "haunting" is now over. I adjusted
the VFO knob to put a bit more pressure on the felt washer and now it
stays put when I turn loose of the knob.

Dave

Dave Sublette wrote:

> If this is a duplicate, I appologize, but I posted it 18 hours ago and
> it hasn't appeared. Is there some delay built into this relector??
>
>
>
> Good afternoon,
>
> Now that I have your attention, I don't really think that my K2 is
> haunted, but it does seem to want to tune itself.
>
> As I tune the knob up and down the bands and come to the frequency that
> I want to listen or transmit on, I stop turning the knob and I take my
> hand off. The knob is fully stopped when I do this. As I watch the
> readout after taking my hand off, the frequency starts to change slowly,
> sometimes adding (or subtracting) as much as 80 hz to the frequency at
> which I stopped the knob. The knob is actually turning by itself. It
> may go either direction and seems not to be correlated to whichever
> direction of rotation I was using when I stopped turning.
>
> I have been using the K2 regularly on the HF bands only for the past few
> weeks. Since building the unit last spring, I have used it mainly as an
> IF rig on the microwave bands. Until the last day or two, I haven't
> noticed the "self tuning" feature.
>
> Perhaps this phenominom has been previously noted and a fix found. I
> cheerfully admit that I haven't done any research in the Elecraft
> Archives.
>
> So....what say ye about this?
>
> Dave, K4TO
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Dave Sublette

Re: Haunted K2

In reply to this post by Dave Sublette

> If this is a duplicate, I appologize, but I posted it 18 hours ago and
> it hasn't appeared. Is there some delay built into this relector??
>
>
>
> Good afternoon,
>
> Now that I have your attention, I don't really think that my K2 is
> haunted, but it does seem to want to tune itself.
>
> As I tune the knob up and down the bands and come to the frequency that
> I want to listen or transmit on, I stop turning the knob and I take my
> hand off. The knob is fully stopped when I do this. As I watch the
> readout after taking my hand off, the frequency starts to change slowly,
> sometimes adding (or subtracting) as much as 80 hz to the frequency at
> which I stopped the knob. The knob is actually turning by itself. It
> may go either direction and seems not to be correlated to whichever
> direction of rotation I was using when I stopped turning.
>
> I have been using the K2 regularly on the HF bands only for the past few
> weeks. Since building the unit last spring, I have used it mainly as an
> IF rig on the microwave bands. Until the last day or two, I haven't
> noticed the "self tuning" feature.
>
> Perhaps this phenominom has been previously noted and a fix found. I
> cheerfully admit that I haven't done any research in the Elecraft
> Archives.
>
> So....what say ye about this?
>
> Dave, K4TO
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

Tom Hammond-3

Re: Haunted K2

In reply to this post by Dave Sublette

Hi Dave:

This is probably doe to the fact that the brass counterweight inside
the back of the VFO tuning knob is just a slight bit eccentric with
regard to weight... just about all K2 VFO knobs will demonstrate this
'quality' of there's insufficient rotational resistance applied to
the back side of the knob.

Add a small bit more 'resistance' to the knob tension via the felt
pad which SHOULD reside between the knob and the front panel.

I've found the easiest way to mete-out tiny amounts of rotational
resistance is to completely loosen one of the two VFO knob setscrews,
and then to loosen the 2nd one and to re-tighten it JUST to the point
that it will keep the knob from pulling off the encoder shaft. THEN,
with the butt end of a small screwdriver, I'll 'tap' on the center of
the VFO knob, pushing the knob in toward the front panel and checking
rotational resistance following each 'tap'. Once I get the resistance
where I want it, I'll first tighten the 'snugged' setscrew and then
the loose one.

Done.

At 08:39 AM 1/4/2006, you wrote:

>If this is a duplicate, I appologize, but I posted it 18 hours ago
>and it hasn't appeared. Is there some delay built into this relector??
>
>
>
>Good afternoon,
>
>Now that I have your attention, I don't really think that my K2 is
>haunted, but it does seem to want to tune itself.
>
>As I tune the knob up and down the bands and come to the frequency that
>I want to listen or transmit on, I stop turning the knob and I take my
>hand off. The knob is fully stopped when I do this. As I watch the
>readout after taking my hand off, the frequency starts to change slowly,
>sometimes adding (or subtracting) as much as 80 hz to the frequency at
>which I stopped the knob. The knob is actually turning by itself. It
>may go either direction and seems not to be correlated to whichever
>direction of rotation I was using when I stopped turning.
>
>I have been using the K2 regularly on the HF bands only for the past few
>weeks. Since building the unit last spring, I have used it mainly as an
>IF rig on the microwave bands. Until the last day or two, I haven't
>noticed the "self tuning" feature.
>
>Perhaps this phenominom has been previously noted and a fix found. I
>cheerfully admit that I haven't done any research in the Elecraft Archives.
>
>So....what say ye about this?
>
>Dave, K4TO
>
>_______________________________________________
>Elecraft mailing list
>Post to: [hidden email]
>You must be a subscriber to post to the list.
>Subscriber Info (Addr. Change, sub, unsub etc.):
>http://mailman.qth.net/mailman/listinfo/elecraft
>
>Help: http://mailman.qth.net/subscribers.htm
>Elecraft web page: http://www.elecraft.com

Vic K2VCO

Re: Haunted K2

In reply to this post by Dave Sublette

Dave Sublette wrote:

> Now that I have your attention, I don't really think that my K2 is
> haunted, but it does seem to want to tune itself.

Since you implied that the knob is actually turning, I think you have a
simple problem solved by tightening the pressure on the felt washer, as
others have mentioned.

However, if the knob is *not* turning, and your K2 is older than serial
no. 2696 you may have this problem:

<http://www.elecraft.com/Apps/Alert16.html>

This is very easy to fix. I had this happen to me once and believe it
or not, the K2 tuned itself to the frequency of SV2ASP, Monk Apollo on
Mt. Athos, one of the rarest DX stations in the world, on one of his
even rarer forays onto CW (yes, it really was him)! And I worked him!

So maybe you don't want to fix it.
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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Ron D'Eau Claire-2

RE: Haunted K2

In reply to this post by Dave Sublette

It sounds as if you fixed the problem by tightening the knob, but that isn't
the only reason for "hands off" frequency changes.

There was an encoder issue in older K2's that can cause that sort of thing
to happen intermittently too. The frequency would increment on its own
because the firmware was mistakenly reading changes in the encoder output
during transmit as actual knob movement. The result was a steadily changing
frequency with both hands off!

That was solved with a simple wiring change documented here several years
ago and subsequently fixed in firmware. If you have 2.02E firmware or later
you have the fix.

Ron AC7AC

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