The W7NQN line filter is a differential-mode filter. You need a filter that
is designed for common-mode filtering.
Dave WX7G
On Jun 21, 2012 10:32 AM, "Wayne Willenberg" <wewill747@gmail.com> wrote:
> As I mentioned in a post a few days ago, I am at the very beginning of
> being able to operate on 160 and 80M’s. (To date, I have only operated on
> 10, 15 and 20M.) I have been doing a lot of reading, primarily ON4UN’s
> “Low-Band DXing.”
>
>
> My rig (FT-dx5000) is located on a desk. Immediately under the desk is my
> computer, and just above the rig is a shelf on which sits 2 flat-screen
> monitors.
>
>
> One of the points made in “Low-Band DXing” is the necessity of reducing
> noise in the shack. The author states at page 7-75: “It is essential to
> feed the equipment at the shack through high-quality mains filters.” In
> looking for such filters, I have come across the W3NQN AC Line Filter. It
> seems to be built with quality components, but I have not been able to find
> any specs on the amount of attenuation it provides to EMI and RFI noise at
> various frequencies (either common or differential mode). Could someone
> recommend a “high-quality mains filter” or comment on the W3NQN filter?
>
>
> The author goes on to state: “The bottom side of the operating table in my
> shack is completely covered with aluminum sheet. This represents a lot of
> capacitance and virtually zero inductance, which is just what you want!
> Quality mains filters are bolted directly to those sheets and the mains
> outlet to which the equipment is connected is connected as well. The
> ground plane is connected with very short low-inductance wide straps to
> long copper ground rods.” Would someone please explain to me the purpose
> of this ground plane and how it helps reduce noise? How does “a lot of
> capacitance and virtually zero inductance” under a transceiver help reduce
> noise?
>
>
> Thanks in advance for advice and help for a newcomer.
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|