Tom:
Thanks for the clarification. ... It helps a lot.
I don't know if I'll get to it today, but this is certainly worth a try.
If you get any thoughts from your engineer friend, please pass them along.
If you want to write to me privately, my address is:
[log in to unmask]
Tom Behler: KB8TYJ
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Fowle
Sent: Saturday, February 20, 2016 11:52 PM
To: [log in to unmask]
Subject: Re: Next RFI Update, and question for Tom: WA6IVG
tom,
My thought is this thing would replace the ground wire from the common shack
point or the outside ground point on your window panel, going to the ground
rod.
If I were going to mess with this, and it is purely hypothesis, I'd make the
common mode chokes maybe 8 turns on a 6 or 8 inch diameter form.
At the ground rod end, I'd connect the center and shield together and to the
ground rod.
At the top, just the center conductor to the ground on your window panel.
Again this is perhaps nonsense. purely hypothetical, my vague theory is the
chokes would keep common mode current off the outside of this new type of
"shielded ground"
I'd much rather see you put common mode chokes in the feeds near your actual
antennas, but understand the weather makes that difficult.
Gaads Tom, you might just have to turn off the "boots" <HORRORS!>
I've written to my engineer friend discribing the aforementioned shielded
ground, we'll see if he has anyting to say.
Tom Fowle WA6IVG
On Sat, Feb 20, 2016 at 11:30:06PM -0500, Tom Behler wrote:
> This is a multipart message in MIME format.
>
> ------=_NextPart_000_0001_01D16C36.A1ED6AE0
> Content-Type: text/plain;
> charset="us-ascii"
> Content-Transfer-Encoding: 7bit
>
> Hi, all.
>
>
>
> I thoroughly checked all of my coax jumpers in the shack for
> continuity, and all looked good. But, RFI issues still occurred.
>
>
>
> I then found a few small RG9913 jumpers I had lying around, and
> actually had two snap-on RF chokes that could accommodate that size of
> coax. Put one at the output of the TS590, and the other between the
> output of my MFJ998 auto-tuner, and the common connector on my
> six-position Alpha Delta antenna switch. Still no joy.
>
>
>
> Now, I have a question for Tom: (WA6IVG):
>
>
>
> In your last post with the subject of "shielded ground", you posed a
> possible solution for an in-the-shack common ground. You said:
>
>
>
> How about a piece of coax as ground wire with center conductors used
> as the actual ground.
>
> Now take the coax and wind a common mode choke in it at each end, but
> do nothing with the shield at the top and ground the shield at the
bottom."
>
>
>
> I'm a bit confused: where exactly would you connect both ends of this
> new grounding cable made out of coax? Obviously, one end would go to
> the common ground connection on my feed-through panel, but I'm not
> sure where the other end would go. Also, how would you ground the
> shield at the other end of the cable? And, what would you recommend
> for the size of the common mode chokes on each end?
>
>
>
> I have some extra coax here that I'd be willing to try this with
> sometime tomorrow.
>
>
>
> Tom Behler: KB8TYJ
>
>
>
>
>
>
>
>
> ------=_NextPart_000_0001_01D16C36.A1ED6AE0
> Content-Type: text/html;
> charset="us-ascii"
> Content-Transfer-Encoding: quoted-printable
>
> <html xmlns:v=3D"urn:schemas-microsoft-com:vml" =
> xmlns:o=3D"urn:schemas-microsoft-com:office:office" =
> xmlns:w=3D"urn:schemas-microsoft-com:office:word" =
> xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" =
> xmlns=3D"http://www.w3.org/TR/REC-html40"><head><meta =
> http-equiv=3DContent-Type content=3D"text/html; =
> charset=3Dus-ascii"><meta name=3DGenerator content=3D"Microsoft Word
> 14 = (filtered medium)"><style><!--
> /* Font Definitions */
> @font-face
> {font-family:Calibri;
> panose-1:2 15 5 2 2 2 4 3 2 4;}
> /* Style Definitions */
> p.MsoNormal, li.MsoNormal, div.MsoNormal
> {margin:0in;
> margin-bottom:.0001pt;
> font-size:11.0pt;
> font-family:"Calibri","sans-serif";}
> a:link, span.MsoHyperlink
> {mso-style-priority:99;
> color:blue;
> text-decoration:underline;}
> a:visited, span.MsoHyperlinkFollowed
> {mso-style-priority:99;
> color:purple;
> text-decoration:underline;}
> p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
> {mso-style-priority:99;
> mso-style-link:"Plain Text Char";
> margin:0in;
> margin-bottom:.0001pt;
> font-size:11.0pt;
> font-family:"Calibri","sans-serif";}
> span.EmailStyle17
> {mso-style-type:personal-compose;
> font-family:"Calibri","sans-serif";
> color:windowtext;}
> span.PlainTextChar
> {mso-style-name:"Plain Text Char";
> mso-style-priority:99;
> mso-style-link:"Plain Text";
> font-family:"Calibri","sans-serif";}
> .MsoChpDefault
> {mso-style-type:export-only;
> font-family:"Calibri","sans-serif";}
> @page WordSection1
> {size:8.5in 11.0in;
> margin:1.0in 1.0in 1.0in 1.0in;}
> div.WordSection1
> {page:WordSection1;}
> --></style><!--[if gte mso 9]><xml>
> <o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" />
> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout
> v:ext=3D"edit"> <o:idmap v:ext=3D"edit" data=3D"1" />
> </o:shapelayout></xml><![endif]--></head><body lang=3DEN-US
> link=3Dblue = vlink=3Dpurple><div class=3DWordSection1><p
> class=3DMsoNormal>Hi, = all.<o:p></o:p></p><p
> class=3DMsoNormal><o:p> </o:p></p><p = class=3DMsoNormal>I
> thoroughly checked all of my coax jumpers in the = shack for
> continuity, and all looked good. But, RFI issues still =
> occurred.<o:p></o:p></p><p class=3DMsoNormal><o:p> </o:p></p><p =
> class=3DMsoNormal>I then found a few small RG9913 jumpers I had lying
> = around, and actually had two snap-on RF chokes that could
> accommodate = that size of coax. Put one at the output of the
> TS590, and the = other between the output of my MFJ998
> auto-tuner, and the common = connector on my six-position Alpha Delta
> antenna switch. Still no = joy.<o:p></o:p></p><p
> class=3DMsoNormal><o:p> </o:p></p><p = class=3DMsoNormal>Now, I
> have a question for Tom: = (WA6IVG):<o:p></o:p></p><p
> class=3DMsoNormal><o:p> </o:p></p><p = class=3DMsoNormal>In your
> last post with the subject of “shielded = ground”, you
> posed a possible solution for an in-the-shack common = ground.
> You said:<o:p></o:p></p><p = class=3DMsoNormal><o:p> </o:p></p><p
> class=3DMsoPlainText>How about = a piece of coax as ground wire with
> center conductors used as the actual = ground. <o:p></o:p></p><p
> class=3DMsoPlainText>Now take the coax and = wind a common mode choke
> in it at each end, but do nothing with the = shield at the top and
> ground the shield at the = bottom.”<o:p></o:p></p><p =
> class=3DMsoPlainText><o:p> </o:p></p><p =
> class=3DMsoPlainText>I’m a bit confused: where exactly
> would = you connect both ends of this new grounding cable made out of
> = coax? Obviously, one end would go to the common ground
> connection = on my feed-through panel, but I’m not sure where
> the other end = would go. Also, how would you ground the shield
> at the other end = of the cable? And, what would you recommend
> for the size of the = common mode chokes on each end?<o:p></o:p></p><p
> = class=3DMsoPlainText><o:p> </o:p></p><p class=3DMsoPlainText>I
> have = some extra coax here that I’d be willing to try this with
> sometime = tomorrow.<o:p></o:p></p><p
> class=3DMsoPlainText><o:p> </o:p></p><p =
> class=3DMsoPlainText>Tom Behler: KB8TYJ<o:p></o:p></p><p =
> class=3DMsoPlainText><o:p> </o:p></p><p =
> class=3DMsoPlainText><o:p> </o:p></p><p =
> class=3DMsoNormal><o:p> </o:p></p></div></body></html>
> ------=_NextPart_000_0001_01D16C36.A1ED6AE0--
|
