Jo Jo Kracko said:
Too bad this station couldn't do anything to improve on the 85 watts at night. Didn't WPEP have more juice going at night when it was on the air ? Wonder how that 30kw will do over the water into Yarmouth Nova Scotia and up the coast there ?
WNSH required an FCC waiver for its low antenna efficiency which results from the combination of a very short tower--albeit a top-loaded one--and the fact that the tower is mounted on solid rock, which has minimal conductivity. As explained in the application for increased daytime power, it was impossible to bury the ground radials as required by good engineering practice and by the FCC rules. The radials are simply lying on top of the rock. The existing nighttime RMS field, stated as 86.53 mV/m, appears to be a fictional calculated value based on the tower's 66-degree electrical height and the standard FCC curves, which assume a normally effective ground system, which WNSH doesn't have. Similarly, the stated 30-kW daytime RMS field of 1625 mkV/m@1 km must be a calculated value based on the same fictional assumptions, because that field is well above the Class D minimum of 281.7 mV/m/kW@1 km. A field of 1625 mV/m @ 1 km with 30 kW would not require a waiver. I think WNSH's day signal will have an RMS value closer to 1079 mV/m @ 1 km.
In fact, I think the the record for the 85W night operation AFTER the daytime power increase contains the truth. Its RMS field is stated as 57.41 mV/m @ 1km. (I got the 1079 mV/m daytime field by scaling up this 57.41 mV/m nighttime number.) That efficiency makes 85W equivalent to 44W into a an antenna with the normal minimum Class D efficiency and it similarly makes 30 kW the equivalent of less than 15 kW. WPEP's tower, on the other hand, was more than 1/4 wavelength high and the ground system was apparently quite effiective. The result is that WPEP antenna must have produced much less high-angle radiation, allowing a night power in the neighborhood of 250W, enough for WPEP to have been classified as a Class B AM, not a Class D.
High-angle radiation is crucial in this case because of the Class B station in Laval QC (Montreal), which must be protected. I think the FCC's assumption must be that if the signal isn't going out in the horizontal plane, where it belongs, it has to be going upward, with the result that it takes much less power to produce a high-angle skywave similar to what WPEP produced. The solution would be to directionalize, but the signal would have to be aimed south--away from Beverly and mostly over water. No way Keating is going to get involved in another DA. His last involvement was a disaster. The right thing to do would be to move WNSH to the WESX tower, the top portion of which could be skirted to reduce the tower's electrical height to about 190 degrees at 1570. WESX could increase power somewhat to compensate for the reduced efficiency. The problem is that such a move is tied up with the plan of thr late owner of WESX, Otto Miller, to donate the WESX site to the Town of Marblehead. I don't know where that stands, but if Miller's plan dies, as it should, the WESX site would be ideal for both stations, and WNSH could get the same coverage with with WAY less than 30 kW (less than 10 kW, it appears). WNSH's night power could probably be increased to somewhere around 200W and possibly more, which would result in a significant improvement in night coverage.
