[K3] birdies and cable routing?

[Edward R Cole]

John,

As Wayne has stated, routing varies with individual radios, so what
works for one may not be optimum for others (definitely a trial and
error process).  A though occured to me, though.  Since cable layout
seems to make a difference for some, I wonder if double-shielded
cables would make any difference?  That would only if leakage is
occuring.  If birdies are being conducted over the coax shields
(common-mode) then perhaps a few ferrite beads would help?

This stuff is in the area of "magic touch" and hard to reproduce as
"exact science".

73, Ed - KL7UW

------------------------------

Message: 15
Date: Wed, 8 Sep 2010 08:29:01 -0400
From: John Fritze <[hidden email]>
Subject: [Elecraft] [K3] birdies and cable routing?
To: [hidden email]
Message-ID:
         <AANLkTimD5oiF=[hidden email]>
Content-Type: text/plain; charset=ISO-8859-1

  " He sent along a pictorial of a Italian gent
who has rerouted his TMP cables in such a way to
substantially reduce receiver birdies."


Perhaps Elecraft could post the photos somewhere so that we might
decide if it makes a difference in our individual rigs (mine
included).

John
K2QY



73, Ed - KL7UW, WD2XSH/45
======================================
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[Geoffrey Mackenzie-Kennedy]

Ed,

Double-shielded coax would most likely not make much if any difference to
the level of birdies if the coax cables pass over or are close to an
unshielded pcb, or some other unshielded source involved in generating a
birdie. If moving the coax cables affects the level of birdies, then the
outers of one or more cables would appear to be one path involved in the
generation of birdies, and using double-shielded coax would only move this
path to the outside of the second (added) braid of the coax.

Not an "exact science" but there are some fundamental rules.

73,

Geoff
GM4ESD


----- Original Message -----
From: "Edward R. Cole" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, September 08, 2010 7:35 PM
Subject: [Elecraft] [K3] birdies and cable routing?

> John,
>
> As Wayne has stated, routing varies with individual radios, so what
> works for one may not be optimum for others (definitely a trial and
> error process).  A though occured to me, though.  Since cable layout
> seems to make a difference for some, I wonder if double-shielded
> cables would make any difference?  That would only if leakage is
> occuring.  If birdies are being conducted over the coax shields
> (common-mode) then perhaps a few ferrite beads would help?
>
> This stuff is in the area of "magic touch" and hard to reproduce as
> "exact science".
>
> 73, Ed - KL7UW

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