Why does WEEI signal pattern go out to sea?

[Gadon]

It is amazing how well the Boston AM stations can be heard in Halifax, NS after dark without much effort to tune them in...

 

[aaronread]

I remember one night a couple of years ago I was driving up in La Malbaie, Quebec (about 90 miles north of Quebec City) and tried tuning to 850 to see if I could here the Red Sox game. It must have been a great skip because the station came in loud and clear. Once I drove inland a bit it faded out.

Technically it's reflection, not skip...skip refers more to transient atmospheric conditions that can cause FM signals to go for much further than they would otherwise. Reflection happens every night as the sun energizes certain layers of the atmosphere. During the day, the energized layers do not reflect signals at AM wavelengths, but at night that layer de-energizes and allows signals to reach a layer that DOES reflect.

That said, I drove from Boston to Banger, ME listening to a Sox-at-Angels game (10pm start ET) the whole way along I-95. Wasn't until I got within 30 minutes of Bangor that the signal started getting noticeably weaker. WEEI does do a great job "covering" most of Maine at night.

BTW, as to why 850 has such a tight directional pattern to the east and yet is located in a place where a lot of potentially lucrative audience is not east of them (i.e. Metrowest) it's quite simple: when that tower array was built, the "Metrowest" we know today didn't exist. It was mighty rural out in those parts, and 850 covered all the areas where the population was. 680AM (WRKO today) is a similar story. Thanks to prohibitively high costs for land, NIMBY local zoning, strict protection rules, and the dreaded FCC "ratchet rule", there is realistically no way that WEEI or WRKO could move their tower sites further west to get more of the Metrowest population.

 

[HHH]

"It is amazing how well the Boston AM stations can be heard in Halifax, NS after dark without much effort to tune them in..."

I remember that the old WMEX (1510) from their Squantum transmitter used to bomb into Halifax, NS at night, and right up the coast
to New Brunswick and Labrador. A friend of mine was in the service and said that all the Massachusetts guys used to listen to Arnie "the Woo" on base up in Goose Bay at night. I remember hearing that one guy was from Medfield and couldn't get WMEX at night at his home, but was amused to hear it clearly hundreds of miles away in Goose Bay.

 

[DanStrassberg]

"It is amazing how well the Boston AM stations can be heard in Halifax, NS after dark without much effort to tune them in..."

I remember that the old WMEX (1510) from their Squantum transmitter used to bomb into Halifax, NS at night, and right up the coast
to New Brunswick and Labrador. A friend of mine was in the service and said that all the Massachusetts guys used to listen to Arnie "the Woo" on base up in Goose Bay at night. I remember hearing that one guy was from Medfield and couldn't get WMEX at night at his home, but was amused to hear it clearly hundreds of miles away in Goose Bay.

The transmitter site was almost at the water's edge. The less land the signal has to traverse before its hits salt water, the stronger the signal will be when it arrives at the other side of the body of water. But WMEX's 5 kW signal wasn't THAT strong in, say, Yarmouth NS. That's why you didn't have to go very far inland from the water's edge in Yarmouth to lose the 1510 signal. When WMEX increased its day power to 50 kW and changed its day pattern to a modified cardioid aimed east-northeast (still from Quincy), the daytime signal in Yarmouth got a lot stronger, though, and carried quite a few miles inland. At the water's edge in Yarmouth in those days, WMEX was, for all practical purposes, a local signal!