Re: KPA500: How to troubleshoot "distorted audio" NOW: BONDING

[Robert .]

Bonding laptop
any good ideas on bonding laptop, seems more difficult with no designed
place to connect to
(recent failure of another usb to serial cable....., a cheap blue one
probably hot from China)

73 Robert W5AJ


-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Jim
Brown
Sent: Monday, May 04, 2015 2:18 AM
To: [hidden email]
Subject: Re: [Elecraft] KPA500: How to troubleshoot "distorted audio"

On Sun,5/3/2015 10:21 PM, Matt Zilmer wrote:
> Check your RF ground.

WRONG! A connection to mother earth has nothing to do with solving RFI
issues, nor does it make antennas work better.

RATHER -- check BONDING and SHIELD connections -- is there a coax with a bad
shield connection? Is every equipment chassis in the station bonded to every
other chassis? That includes computer, rig, power amp, other accessories,
the PSU for the rig. Is there a bond from there to power system "ground?"

Since this is a problem that was not there before and is now, look for
things that could have failed or changed. If it were not for that, I would
be suggesting common mode chokes at the feedpoint of the antenna in use.

When it worked before and doesn't work now, always ask "what might have
changed (broken)?"

73, Jim K9YC
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[Robie Elms-2]

Good question.  Would the point where the video connector attaches to the laptop work?  

Robie - AJ4F

> On May 4, 2015, at 09:55, Robert Wood <[hidden email]> wrote:
>
>
> Bonding laptop
> any good ideas on bonding laptop, seems more difficult with no designed
> place to connect to
> (recent failure of another usb to serial cable....., a cheap blue one
> probably hot from China)
>
> 73 Robert W5AJ
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Jim
> Brown
> Sent: Monday, May 04, 2015 2:18 AM
> To: [hidden email]
> Subject: Re: [Elecraft] KPA500: How to troubleshoot "distorted audio"
>
>> On Sun,5/3/2015 10:21 PM, Matt Zilmer wrote:
>> Check your RF ground.
>
> WRONG! A connection to mother earth has nothing to do with solving RFI
> issues, nor does it make antennas work better.
>
> RATHER -- check BONDING and SHIELD connections -- is there a coax with a bad
> shield connection? Is every equipment chassis in the station bonded to every
> other chassis? That includes computer, rig, power amp, other accessories,
> the PSU for the rig. Is there a bond from there to power system "ground?"
>
> Since this is a problem that was not there before and is now, look for
> things that could have failed or changed. If it were not for that, I would
> be suggesting common mode chokes at the feedpoint of the antenna in use.
>
> When it worked before and doesn't work now, always ask "what might have
> changed (broken)?"
>
> 73, Jim K9YC
> ______________________________________________________________
> 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 Message
> delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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[Jim Brown-10]

On Mon,5/4/2015 7:55 AM, Robert Wood wrote:
> Bonding laptop
> any good ideas on bonding laptop, seems more difficult with no designed
> place to connect to
> (recent failure of another usb to serial cable....., a cheap blue one
> probably hot from China)

On many laptops, the shell of a DB-series connector is bonded to the
chassis. That's what I've used.  I solder a short wire to a small lug
that can fit under the retaining screw, and connect the wire to a single
Power Pole. I do my in-shack bonding with single Power Pole jumpers made
from either stranded #12 or braid stripped from transmitting coax, with
heat shrink as a jacket.

73, Jim K9YC
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