Re: Wee Eye

[Dan Strassberg <dan.strassberg@worldnet.att.net>]

At 08:44 PM 6/17/98 -0400, you wrote:
>When I lived in Mass, the old 590 came in loud and clear at night on the
>North Shore (Peabody,Danvers,Beverly) on my old 77 Ford Maverick's
>radio. It was also strong on my clock radio in Peabody-I know WEEI had
>(has?) a north-south pattern...could this explain why 590 was fine,but
>1510 (WMEX et al) and 1600 (WUNR) were unlistenable in the same
>location?
>
When did you have trouble picking up 1510 in the Danvers-Peabody area? I'll
wager it was since March of 1981 when the 1510 TX moved from North Quincy to
the Waltham-Belmont line. At the same time, the night power increased from 5
kW to 50 kW--directionalized TOWARD the North Shore. When the TX was in N
Quincy, the signal on the North Shore (and in Boston's financial district)
was excellent, even at night, despite the lower night power. Until the TX
move, however, the station was virtually unlistenable at night in most of
the rest of the Boston metro. After the TX move and night power increase,
the nighttime signal to the immediate west of Boston improved _a lot_, but
the signal on the North Shore suffered. And because of the directional
pattern and the wicked co-channel and adjacent-channel interference, once
you get outside of 128 to the north or west of Boston, the signal disappears
very rapidly.

The reasons for your reception reports is soil conductivity and dial
position. From Medford to Danvers-Peabody the signal travels over or very
near salt water, which is the best conductor of medium-wave radio signals
found in nature. From Waltham-Belmont (1510) or Newton-Brookline (1600), the
signal must first travel quite a way over land. And in New England, the
conductivity of the land is about 1/2500 of the conductivity of sea water.
In addition, with typical soil conductivity, 5 kW at 590 covers about as
well as 200 kW would at 1500 to 1600. Moreover, when people say that 590's
pattern goes north and south, many people envision a figure eight, which is
not exactly correct. Although there is a null to the west (equivalent to
about 300W), the signal to the east is equivalent to almost 5 kW. The
signals to the north and south are stronger still.

- -------------------------------
Dan Strassberg (Note: Address is CASE SENSITIVE!)
ALL _LOWER_ CASE!!!--> dan.strassberg@worldnet.att.net
(617) 558-4205; Fax (617) 928-4205

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