Not sure what you mean either. "Inside" means... well.... inside, i.e. a
differential-mode path consisting of a center conductor and the inner surface of
the outer conductor. Signals + noise get "inside" via the antenna and anything
you do to the outside does not affect them. I'm sorry, but despite claims to
the contrary, every problem we encounter can't be solved with a common-mode choke.
Wes N7WS
On 5/25/2017 8:08 AM, Edward Mccann via TowerTalk wrote:
Not so sure what you mean by "noise inside the line." It has to get "inside"
somehow, from whence it is choked almost any convenient place along the line prior to the rig
connection.
Slightly off-topic, but an insight into the commercial and aerospace world in
EMI is a brief article linked below. Old hat to many of you, I'm sure. Don't
panic. The link is almost as long as the article.
http://www.mwrf.com/test-measurement/measurements-help-minimize-emi-and-rfi?NL=MWRF-001&Issue=MWRF-001_20170525_MWRF-001_0&sfvc4enews=42&cl=article_1_b&utm_rid=CPG05000004870443&utm_campaign=11276&utm_medium=email&elq2=123c77892aed460e8988051a23926a21
Ed McCann
AG6CX
Sent from my iPhone
On May 24, 2017, at 8:22 PM, Wes Stewart <wes_n7ws@xxxxxxxxxxxx> wrote:
I don't know about the worry of choking the line since it's the noise inside
the line I worry about, but I would (and do) run low-loss coax (LDF-4 or LDF-5).
Wes N7WS
On 5/24/2017 12:24 PM, Jim Brown wrote:
On Wed,5/24/2017 11:40 AM, John Sloop wrote:
Have you considered open wire?
Only if coax is not practical. Assuming a matched load (resonant antenna),
you'll need transformers on each end to get from the low Z of the matched load
to the line, and from the line to the rig. Those transformers are not lossless.
:)
And if it's not a low Z matched load, it's not practical to choke it to kill
noise, which was the reason for the long run in the first place.
73, Jim K9YC
_______________________________________________
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@xxxxxxxxxxxxxx
http://lists.contesting.com/mailman/listinfo/towertalk
|