Hello, Jerry?

[Dan.Strassberg]

WMEX's old two-tower 5-kW DA-1 pattern from Quincy was an inverted
figure eight, with a relatively narrow minor lobe to the south and a
broad major lobe to the north. That WMEX should have delivered a
pretty good skywave to Montreal at night is not at all surprising. But
a good groundwave in Lowell is kind of surprising. I don't know the
height of the towers but I would be surprised if they were much more
than quarter wave, so there was probably plenty of high-angle
radiation, which would help to explain the good signal in Montreal.
But Lowell is kind of close in to have gotten much of a skywave. The
skywave would have gotten better (on average) as you drove up Route 3
from the Merrimac Valley into New Hampshire. My guess is that it would
have been pretty potent on most nights in Concord NH.

The current four-tower 50-kW night pattern from Waltham is quite
different. The major lobe is centered pretty much due east over
downtown Boston and then along the coast to cover the North Shore.
There is a minor lobe to the north right on the edge of the major lobe
(actually, the minor lobe kind of merges into the major lobe). That
minor lobe was designed into the pattern to provide coverage to the
north and to take advantage of the radiation grandfathered from the
old 5-kW pattern. It's responsible for whatever signal gets to
Burlington at night. On paper, because the Waltham site is so much
closer to Burlington than the Quincy site was and the inverse-distance
field to the north is almost as great as peak of the old 5-kW major
lobe, you'd think that the signal in Burlington at night would br
pretty good. I have found it to be generally kind of ragged. The
Waltham array uses towers almost 200-degrees tall, so they are quite
efficient and they should push the area of good skywave further out
than it was with the shorter Quincy towers.

But, of course, the Waltham site is in an area of high population
density and the high density of houses and paved streets and driveways
just accentuates the effect of the natually pitiful soil conductivity.
Couple that with being high up on the dial and it should not be
surprising that the 50-kW signal from 200-degree towers is generally
not a killer.

-----
Dan Strassberg (dan.strassberg@att.net)
eFax 1-707-215-6367

----- Original Message ----- 
From: "Eli Polonsky" <elipolo@earthlink.net>
To: <boston-radio-interest@lists.BostonRadio.org>
Cc: "Dan.Strassberg" <dan.strassberg@att.net>
Sent: Tuesday, August 28, 2007 5:16 PM
Subject: Re: Hello, Jerry?


> >From: "Dan.Strassberg" <dan.strassberg@att.net>
>>CC: "Keating Willcox" <kwillcox@wnsh.com>,
>> >boston-radio-interest@lists.bostonradio.org
>>To: "Kevin Vahey" <kvahey@gmail.com>,
>>"Bill O'Neill" <me@billoneill.us>
>>Date: Tue, 28 Aug 2007 14:50:44 -0400
>>Subject: Re: Hello, Jerry?
>>
>>In the Merrimac Valley (except maybe near the coast--
>>Newburyport and environs), I would think so. Actually,
>>I'm amazed that she could get WMEX at all at night if
>>she was in the Lowell/Lawrence area. That's probably
>>true even now with 50 kW at night because, although
>>the day patterns send a pretty strong signal to the
>>north, the night pattern is nulled to the north to
>>protect long-dark CJRS, which was due north of us.
>
> Somehow, the old WMEX signal did go north at night.
> Although it couldn't be heard listenably in Concord
> or Framingham (or barely in Newton, where I grew up)
> it did go north via the Routes 93 and 3 directions
> and it could be heard up through New Hampshire and
> eastern/northern Vermont to Montreal Canada, where
> it was loud and clear at night when my family went
> up there for "Expo '67". It was actually better
> northward inland into New England with the old 5kW
> from Quincy than the 50kW from Waltham. I could see
> WMEX may have been audible in Lowell and Lawrence at
> night, but not much farther west.
>
> EP
>
>
>