Hans:
Your initial inquiry asked about CM choke for open (and ladder line, I presume)
feeder.
I passed on K9YC's counsel on the topic.
Your latest message has me a bit confused:
"I have a setup with the tuner isolated from ground and a CCM chock made of 50'
of coax wound around a 4" PVC pipe. The chock is fairly wide band by NOT having
an even pitch on the winding. The choke insure that there is no CM current
entering the shack."
So, for clarity:
1. What antenna is in the air?
2. Is it fed with open wire feedline?
3. Where is your CM choke in the line?
4. From antenna, at you CM Choke, do you connect one side of open wire to coax
center conductor and other to ground?
5. Coming out of CM Choke, are you back to open wire feedline to tuner?
6. Is this open feedline hooked into balanced terminals of tuner?
7. Antenna side seems isolated from ground at tuner. But what about output side
of tuner? Now coax, right, and transceiver chassis ( and therefore shield of
coax) is now grounded. It is this not the case?
PS-what tuner are you using?
Thanks for clarification on this most interesting topic, i.e. A CM Choke for
open feeder.
73,
Ed McCann
AG6CX
Are you using an open wire feed?
Sent from my iPhone
> On Jun 16, 2016, at 3:04 PM, Hans Hammarquist via TowerTalk
> <towertalk@contesting.com> wrote:
>
> I am very fortuned not being surrounded by noise. Next door neighbor is 1000
> feet away with no TV or any other RFI source and next neighbor is 1/2 mile
> away. Wonder if I can make a CM choke for an open feeder. Any idea?
>
>
> Hans - N2JFS
>
>
>
> -----Original Message-----
> From: Jim Brown <jim@audiosystemsgroup.com>
> To: towertalk <towertalk@contesting.com>
> Sent: Thu, Jun 16, 2016 1:19 pm
> Subject: Re: [TowerTalk] Fwd: OWAs or Fans?
>
>> On Thu,6/16/2016 7:26 AM, Hans Hammarquist via TowerTalk wrote:
>> Open wire feeders are simple to use if you know to address a few things
>
>
> The thing that it is NOT POSSIBLE to address is choking the feedline at
> the feedpoint (that is, where it junctions the dipole). This makes the
> antenna inherently noisy in most parts of the real world. Off-center-fed
> antennas like Windoms are even worse in that regard.
>
> This doesn't mean that they don't radiate -- that's NOT the issue.
> There's nothing wrong with these antennas in concept, only that we as
> hams are surrounded by RF noise sources.
>
> 73, Jim K9YC
>
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