WITS/Red Sox

Sat Oct 7 22:59:10 EDT 2006

Doug...

You could start at the link below and then do some "electronic dictionary"
searches on Google, or just enter "definition" and the term in
Google...There really aren't a whole lot of different terms that aren't
related, and after you recognize a few the others will make sense...

http://www.interfacebus.com/Antenna_Terms_A.html

AN UP TO DATE COPY OF "THE RADIO ENGINEER'S HANDBOOK" wouldn't hurt, but
unless you really want to delve into the engineering aspect's of radio, you
should be able to understand 99% of the posts without getting too deep.

The one thing that still gets me is when FCC defines antenna height in
degrees...now I know what it is but I don't know why...feet could be
converted to wavelength for the operating frequency...Oh well...

If you are interested in the technical end just to obtain understanding,
consider a Ham Radio license...then you could talk about this stuff all
day...

Enjoy!

Roger
WA1KAT

----- Original Message ----- 
From: "Doug Drown" <revdoug1@verizon.net>
To: "Dan Strassberg" <dan.strassberg@att.net>; "Laurence Glavin"
<lglavin@mail.com>; "Garrett Wollman" <wollman@csail.mit.edu>;
<bri@bostonradio.org>
Sent: Saturday, October 07, 2006 7:08 PM
Subject: Re: WITS/Red Sox

> <<WKOX, which, at night, currently also uses a two-tower array to produce
a
> modified cardioid pattern, has even taller towers. (They are top-loaded to
> an electrical length of 214 degrees.) These produce even higher
>  efficiency--426 mV/m @ 1 km using a power of 1 kW.>>
>
> Question from a broadcasting non-professsional (I've done a lot of
> broadcasting but have little understanding of radio engineering other than
> running a board): I've read a lot of posts like this in this forum, and
> would like to know if any of you could recommend any good textbooks that
> would explain, in comparatively simple terms, the sort of thing you're
> talking about here.  I find it fascinating, but I don't know what all the
> terms mean, and aside from knowing (for example) what kHz, kW, and "null"
> refer to, the technical lingo is almost entirely lost on me.   Any
> suggestions?
>
> -Doug
>
> ----- Original Message ----- 
> From: "Dan Strassberg" <dan.strassberg@att.net>
> To: "Laurence Glavin" <lglavin@mail.com>; "Garrett Wollman"
> <wollman@csail.mit.edu>; <bri@bostonradio.org>
> Sent: Saturday, October 07, 2006 5:26 PM
> Subject: Re: WITS/Red Sox
>
>
> > WUNR uses the same two-tower directional pattern day and night. The
towers
> > are spaced 105 degrees apart along an axis at 70 degrees. As you
observed,
> > the towers are quite tall--greater than half wave--205 degrees to be
> > precise. Consequently, the efficiency shown in CDBS is quite high--410
> > mV/m/kW @ 1 km, although it has been speculated that maybe the ground
> > system, which is almost 60 years old if it has never been replaced, is
in
> > serious disrepair. A deteriorated ground system could explain an
> efficiency
> > significantly lower than the value shown in CDBS. The pattern is a
> modified
> > cardioid with radiation minima 31 or 32 degrees off axis at 219 degrees
to
> > protect WWRL and at 282 degrees to protect E Longmeadow. (A true
cardioid
> > consists of towers exactly 90 degrees apart and has only one radiation
> > minimum, along the axis of the array.)
> >
> > WKOX, which, at night, currently also uses a two-tower array to produce
a
> > modified cardioid pattern, has even taller towers. (They are top-loaded
to
> > an electrical length of 214 degrees.) These produce even higher
> > efficiency--426 mV/m @ 1 km using a power of 1 kW. The axis of WKOX's
> array
> > is 35 degrees; in other words, WKOX's current pattern is rotated
> > counterclockwise from WUNR's pattern by 35 degrees. I believe that WKOX
> was
> > built that way because, when the move to 1200 was granted, secondary
> > stations on what had been Class IA channels were restricted to 1 kW at
> > night. The 35-degree orientation allowed a 1 kW signal to cover
> Marlborough
> > pretty well at night. Had WKOX been allowed higher night power when it
> first
> > moved to 1200, the orientation of its towers would probably have been
more
> > clockwise because the azimuth of WOAI is 33 degrees clockwise with
respect
> > to the azimuth of WKOX's towers. (And then later on when WBIX moved in
> with
> > WKOX, it would not have needed to use lower power during critical
hours.)
> >
> > When it looked as if Newton would never approve tower construction at
750
> > Sawmill Brook Parkway, I urged that WKOX move there anyhow and use
WUNR's
> > two existing towers to operate DA-2. It turns out that the existing WUNR
> > towers have, within inches, the same physical spacing as the WKOX towers
> > (105 degrees at 1600 is 78.75 degrees at 1200). Running 50 kW-D from the
> > existing WUNR towers should have presented no problem for WKOX. The
night
> > power would have had to be much lower than 50 kW, however. Because the
> WUNR
> > towers' more clockwise orientation would have reduced radiation to the
> > northwest, it might have been possible for WKOX to run 5 kW at night and
> > still adequately protect CFGO--I'm not sure. But even with 5 kW from a
> site
> > within the City of Newton, it did not appear that WKOX could deliver an
> NIF
> > signal to the requisite 80% of the CoL's population. Hence, the FCC
would
> > have had to grant a waiver.
> >
> > At 1200, WUNR's existing towers are 153.75 degrees high. The resulting
> > efficiency would have been about 7.5% higher than what WKOX will achieve
> > from its new 195' towers--the equivalent of more than 15% higher
> power--not
> > a huge difference, but not trivial either. Since there will be five
towers
> > at the site (of which WKOX will use only three), and two of the three
> > stations that share the site are on frequencies lower than 1600, the
area
> > covered by the new ground system will be greater than that covered by
the
> > existing WUNR ground system. Part of the reason that WKOX is projecting
an
> > efficiency as high as 339 mV/m/kW @ 1 km, is that the ground system of
the
> > two towers that WKOX will not use is still considered to be part of
WKOX's
> > ground system. If WKOX were going to use the existing WUNR towers, a
> larger
> > than normal ground system could also have been employed, somewhat
> improving
> > on the antenna efficiency that would have been achieved from the
> > 153.75-degree towers.
> >
> > --
> > Dan Strassberg, dan.strassberg@att.net
> > eFax 707-215-6367
> >
> > ----- Original Message -----
> > From: "Laurence Glavin" <lglavin@mail.com>
> > To: "Dan Strassberg" <dan.strassberg@att.net>; "Garrett Wollman"
> > <wollman@csail.mit.edu>; <bri@bostonradio.org>
> > Sent: Saturday, October 07, 2006 12:15 PM
> > Subject: Re: WITS/Red Sox
> >
> >
> > >----- Original Message -----
> > >From: "Dan Strassberg"
> > >To: "Laurence Glavin" , "Garrett Wollman" , bri@bostonradio.org
> > >Subject: Re: WITS/Red Sox
> > >Date: Fri, 6 Oct 2006 14:49:15 -0400 In any event, if you find WKOX's
> > current signal listenable for
> > >only a short distance past Worcester (I find it pretty good all the way
> to
> > >the Connecticut border on I-84), the new, "stronger" signal will become
> > >unsatisfactory to you near the west side of Framingham.
> >
> >
> > In this particulat case, I wasn't doing any radio-geekery, that is
trying
> to
> > hold a station to see how far it would go;  I was actively listening to
> > Stephanie Miller and wanted to continue to do so.  I knew AM 1600 in
> > suburban Springfield was carrying it and when I flipped to 1600 I
> > expected a battle between it and WUNR, but was surprised to get the
> > station I wanted quite clearly.  In the past I never had any reason to
> > sample AM 1600 out of Longmeadow, so I had no idea what I'd find.
> > It does indicate that even during the day, WUNR's signal WNW is no great
> > shakes,
> > which backs up your previous assertion that the Samill Brook location
> > isn't exceptional, even though those towers APPEAR efficient for a
> > 1600 khz operation.
> >
> > --
> > ___________________________________________________
> > Play 100s of games for FREE! http://games.mail.com
> >
> >
> >
> >
> >
> >
> >
>
>