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P3 - Appearent P3 Anomoly

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dwines

P3 - Appearent P3 Anomoly

Guys,

My P3 has developed a problem that appears to be some internally generated noise that shows up on the screen but doesn't come from the K3. Below is a link to a video I made this morning for a visual description of the problem. After the P3 has warmed up it will disappear. It will gradually migrate from right to left (higher to lower in freq) and eventually either disappear or go out of range of the display. It doesn't to interfere with reception even when the signal is within the noise boundary.

This problem seems to occur on all bands from 40 thru 10 meters. I haven't seen it below 40 meters. There is no ground lug on the P3 but the K3 itself is well grounded.

http://www.flickr.com/photos/43690708@N02/5684413732/

I didn't show it on the video but when the Select knob is turned even with no function displayed the noise spreads out over a much wider span but then re-concentrates after the knob is left alone.

The P3 has performed flawlessly up to this point. This problem seems to be superficial in that is doesn't otherwise affect the operation of the unit.

Any ideas from anybody especially you guys in Aptos!

Don Wines
K5DW

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W6NEK

Re: P3 - Appearent P3 Anomoly

You're not alone Don. I have the exact same issue. If I place my hand on
the top of the P3 cabinet the displayed noise goes to zero. I'll be
interested to see what kind of feedback you receive.

Frank - W6NEK

----- Original Message -----
From: "Don Wines" <[hidden email]>
To: <[hidden email]>
Sent: Tuesday, May 03, 2011 10:26 AM
Subject: [Elecraft] P3 - Appearent P3 Anomoly

> Guys,
>
> My P3 has developed a problem that appears to be some internally generated
> noise that shows up on the screen but doesn't come from the K3. Below is a
> link to a video I made this morning for a visual description of the
> problem. After the P3 has warmed up it will disappear. It will gradually
> migrate from right to left (higher to lower in freq) and eventually either
> disappear or go out of range of the display. It doesn't to interfere with
> reception even when the signal is within the noise boundary.
>
> This problem seems to occur on all bands from 40 thru 10 meters. I haven't
> seen it below 40 meters. There is no ground lug on the P3 but the K3
> itself is well grounded.
>
> http://www.flickr.com/photos/43690708@N02/5684413732/
>
> I didn't show it on the video but when the Select knob is turned even with
> no function displayed the noise spreads out over a much wider span but
> then re-concentrates after the knob is left alone.
>
> The P3 has performed flawlessly up to this point. This problem seems to be
> superficial in that is doesn't otherwise affect the operation of the unit.
>
> Any ideas from anybody especially you guys in Aptos!
>
> Don Wines
> K5DW

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Guy, K2AV

Re: P3 - Appearent P3 Anomoly

In reply to this post by dwines

When you placed your hand on the P3, you changed its "miscellaneous
chassis resonance" when floating. Try grounding the P3 and see if it
goes away. Sources? That looks most like a switching power supply or
something from a monitor.

Also check to see if the cover itself is somehow (by the paint) not
connecting to the rest of the case.

73, Guy

On Tue, May 3, 2011 at 1:26 PM, Don Wines <[hidden email]> wrote:

> Guys,
>
> My P3 has developed a problem that appears to be some internally generated noise that shows up on the screen but doesn't come from the K3. Below is a link to a video I made this morning for a visual description of the problem. After the P3 has warmed up it will disappear. It will gradually migrate from right to left (higher to lower in freq) and eventually either disappear or go out of range of the display. It doesn't to interfere with reception even when the signal is within the noise boundary.
>
> This problem seems to occur on all bands from 40 thru 10 meters. I haven't seen it below 40 meters. There is no ground lug on the P3 but the K3 itself is well grounded.
>
> http://www.flickr.com/photos/43690708@N02/5684413732/
>
> I didn't show it on the video but when the Select knob is turned even with no function displayed the noise spreads out over a much wider span but then re-concentrates after the knob is left alone.
>
> The P3 has performed flawlessly up to this point. This problem seems to be superficial in that is doesn't otherwise affect the operation of the unit.
>
> Any ideas from anybody especially you guys in Aptos!
>
> Don Wines
> K5DW
>
>
> ______________________________________________________________
> 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
>

Dunc Carter - W5DC

Re: P3 - Appearent P3 Anomoly

I've occasionally had a noise problem with the K3 and P3 combination
that was solved by un-connecting and then re-connecting the coax signal
cable between the K3 and P3 at the P3 end of the cable. The symptom was
noises that tracked the K3 tuning but were not on the K3 transmit frequency.

73, Dunc, W5DC.
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Alan Bloom

Re: P3 - Appearent P3 Anomoly

In reply to this post by dwines

Hi Don,

The first thing I would check is the ground connections in the chassis.
Make sure that the paint has been removed from the sheet metal on the
inside surface around the BNC and the RS-232 connectors. The mounting
nuts on the BNC connectors and the jack screws on the RS-232 connectors
must be tight. The connectors on the RS-232 cables should be screwed
down so the connector shells make good contact.

The paint must also be removed from the sheet metal around each of the
points where it attaches to the 2D fasteners. Also make sure all the
chassis screws are tight.

73,

Alan N1AL

On Tue, 2011-05-03 at 12:26 -0500, Don Wines wrote:

> Guys,
>
> My P3 has developed a problem that appears to be some internally
> generated noise that shows up on the screen but doesn't come from the
> K3. Below is a link to a video I made this morning for a visual
> description of the problem. After the P3 has warmed up it will
> disappear. It will gradually migrate from right to left (higher to
> lower in freq) and eventually either disappear or go out of range of
> the display. It doesn't to interfere with reception even when the
> signal is within the noise boundary.
>
> This problem seems to occur on all bands from 40 thru 10 meters. I
> haven't seen it below 40 meters. There is no ground lug on the P3 but
> the K3 itself is well grounded.
>
> http://www.flickr.com/photos/43690708@N02/5684413732/
>
> I didn't show it on the video but when the Select knob is turned even
> with no function displayed the noise spreads out over a much wider
> span but then re-concentrates after the knob is left alone.
>
> The P3 has performed flawlessly up to this point. This problem seems
> to be superficial in that is doesn't otherwise affect the operation of
> the unit.
>
> Any ideas from anybody especially you guys in Aptos!
>
> Don Wines
> K5DW
>
>
> ______________________________________________________________
> 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
>

gm3sek

Re: P3 - Appearent P3 Anomoly

Alan Bloom wrote:
>
>The paint must also be removed from the sheet metal around each of the
>points where it attaches to the 2D fasteners.

My recent P3 metalwork had much more paint underneath the spray masking
tape than the 3-y-o K3 had. It needed a vicious stainless steel scratch
pen to clean the P3 panels down to bare bright metal around the fixing
points.

>Also make sure all the chassis screws are tight.
>
This is very important in Elecraft's 'flat pack' style of construction.
With no internal chassis and no continuous edge-to-edge bonding between
panels, RF shielding and grounding is *critically* dependent on that
relatively small number of panel-to-panel fixings.

--

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek
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