Classical change in Washington DC

Dan Strassberg
Thu Jan 25 11:57:06 EST 2007

The ratchet rule (hatchet rule?) requres stations making significant
technical changes to reduce interference to other stations. (Many changes
that the FCC classifies as minor are nevertheless significant enough to
invoke the ratchet rule.) On AM, this can necessitate reductions in areas of
caused and received co- and adjacent-channel daytime-contour
overlap. For changes to AM nighttime facilities, the rule forces reductions
in the changing station's contribution to the 50%-exclusion NIF (nighttime
interference-free) contours of usually a handful co- and
first-adjacent channel stations. Remember, NIF calculations have involved
first adjacents for only maybe a decade or so. Therefore, virtually any
change to an AM's night facilities requires pulling in contours in a lot of
directions. It's quite unusual for an AM to be able to improve its night
facilities without shooting itself in the foot. WKOX and WCRN are unusual
cases! I'm not familiar with consequences of the FM ratchet rule, but I
suspect that they are similar to those on AM.


Dan Strassberg
Fax: 1-707-215-6367

----- Original Message -----
From: "A. Joseph Ross" <>
To: "Scott Fybush" <>
Cc: <>; <>
Sent: Thursday, January 25, 2007 12:37 AM
Subject: Re: Classical change in Washington DC

> On 24 Jan 2007 at 14:16, Scott Fybush wrote:
> > What's more, the FCC's inane "ratchet rule" would come into play,
> > negating any nighttime improvement WTOP would get as a result. (I'm on
> > my way into work for the rest of the day, so I'll leave it to our
> > Esteemed and Recuperating Moderator to further explain that one.)
> What's a "ratchet rule"?
> --
> A. Joseph Ross, J.D.                           617.367.0468
>  15 Court Square, Suite 210                 Fax 617.742.7581
> Boston, MA 02108-2503          

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