RE: Question

["Manuelian, Mark" <MANUELIA@boston.cbs.com>]

I believe the question refers to the method that am stations use to
determine power.  It is done by multiplying the antenna input resistance
by the square of the antenna current in amps to yield watts.  This is
basic Ohms Law, where power equals resistance times the current squared.

For directionals the input resistance is measured at the input to the
phasor and is known as the common point.  It is typically 50 ohms.  WBZ's
main site has a common resistance of 50 ohms and runs 32.43 amps of
current.  Which is about 52,600watts.

For non directional systems, the resistance of the tower is used and is
know as the base.  The value varies greatly from installation to
installation.  Shorter towers are typically lower resistance - sometimes
as low as a few ohms.  Half wave towers are usually pretty high and can
be more than several hundred ohms.

Mark Manuelian
 -----Original Message-----
From: Dan Strassberg [SMTP:Dan.Strassberg@worldnet.att.net]
Sent: Friday, March 10, 2000 7:05 AM
To: Mike Fitzpatrick; A. Joseph Ross
Cc: boston-radio-interest@bostonradio.org
Subject: Re: Question

I don't know the details, but it's short for direct measurement of
antenna-input power and it applies to AM stations. Bob Bittner and Peter
George, among others can give a better answer to this one.

 --

Dan Strassberg, dan.strassberg@worldnet.att.net
Phone: 1-617-558-4205, eFax: 1-707-215-6367

 -----Original Message-----
From: Mike Fitzpatrick <fitzradio@map.com>
To: A. Joseph Ross <lawyer@world.std.com>
Cc: boston-radio-interest@bostonradio.org
<boston-radio-interest@bostonradio.org>
Date: Friday, March 10, 2000 3:47 AM
Subject: RE: Question


>this brings another question I had... What's a Direct Measurement in the
>Apps/Actions?
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