RFI
[Top] [All Lists]

Re: [RFI] DirecTV systems

To: rfi@contesting.com
Subject: Re: [RFI] DirecTV systems
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Thu, 28 Mar 2013 10:57:52 -0700
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
On 3/28/2013 10:44 AM, David C. Cole wrote:
I would expect that a mismatch on one port, (i.e. no termination), would
cause RF on that port, as things would become unbalance inside the
splitter thus removing the prefect isolation between ports that should
exist with matched impedances.

No, because there's nothing connected to it to radiate. Think about it -- WIRES radiate when they carry RF current. No wire, no current, no radiation. Likewise, coax radiates ONLY when it carries common mode current (outside the coax), not differential current (inside the coax), or when the shield is degraded, open, or of poor quality.

The only effects of an unterminated port are a slightly higher (a dB or two, depending on the number of ports) and some reflections on the other ports, the strength of which would also depend on the number of ports. .

73, Jim K9YC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi

<Prev in Thread] Current Thread [Next in Thread>