Definitely worth checking into, tom.
Thanks!
Tom Behler: KB8TYJ
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Fowle
Sent: Sunday, February 21, 2016 9:39 PM
To: [log in to unmask]
Subject: Re: Next RFI Update, and question for Tom: WA6IVG
tom,
Just did a quick search for common mode chokes and saw this series from
Palomar engineers.
Not a reccommendation, just an example. Not as expensive as I'd thought.
http://palomar-engineers.com/antenna-products/1-1-balun-kits
tom Fowle WA6IVG
On Sun, Feb 21, 2016 at 06:25:15PM -0800, Tom Fowle wrote:
> tom,
> Remember this gizmo is just a hypothesis based on guess work?
>
> When you can get to putting common mode chokes on your feed lines, you
> have the choice of making them from turns of coax if you have extra
> length of cable or of putting on a bunch of appropriate ferrite beads
> over the feedline near the antenna. The beads are more expensive but
> if you don't have extra feedline maybe easier to accomplish.
> Suppliers of antenna accessories should be able to help you find the
> correct ferrites for your feedline.
>
> Nothing from my friend yet. I'm not mentioning his name with out his
> sayso since he's not a ham.
>
> good luck
> Tom Fowle WA6IVG
>
> On Sun, Feb 21, 2016 at 12:09:44PM -0500, Tom Behler wrote:
> > 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.
> > >
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> > >
> > > 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
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
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> > > 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 =
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