WSRO/650 AM granted power increase

[DanStrassberg]

A few months ago on this board Alex Langer predicted that within a few months his WSRO (Ashland) would be granted a CP to increase power from 250W-D/9W-N ND-U to 1.5 kW-D/62W-N DA-2 using the two tall (440' top-loaded) towers at the station's Mt Wayte Ave site in Framingham. WSRO broadcasts mostly in Brazilian Portuguese to Framingham's sizeable Brazilian community. Besides WSRO, those towers used to be used at night by WKOX/1200 and by day by what was then WBIX/1060. When both of those stations moved out (WKOX (now WXKS (AM)) to Newton and WBIX (now WQOM) to Ashland), the engineering challenge of upgrading WSRO became much more tractable. The fly in the ointment was a never-to-be-built co-channel station in Frederickton NB, which, if the official soil-conductivity map were to be believed, would have received prohibited overlap from WSRO. As Langer predicted, conductivity measurements demonstrated that, if the Frederickton station were ever built, there would, in fact, be no prohibited overlap. Apparently, prohibited third-adjacent overlap with WRKO will not exist either. Some people had predicted such overlap but Entercom seemingly didn't believe them--AFAIK, Entercom never objected, even informally, to WSRO's proposal. If Langer wants to get cracking on this upgrade, it appears that the biggest hangup will be delivery of the directional-antenna phasor, a custom item that is almost never delivered in less than three or four months. The extremely slow business in AM upgrades at the moment as well as the simplicity of the two-tower phasor point to possible delivery within three months, if the order is placed promptly. Since the upgrade involves no tower construction, the usual NIMBY objections should not be an issue.

 

[Eli Polonsky]

It looks like it will be attenuated to the south and southwest. What stations is it protecting? I'm guessing 630 WPRO and 640 WNNZ. Also perhaps 650 WSM and 660 WFAN?

 

[DanStrassberg]

It looks like it will be attenuated to the south and southwest. What stations is it protecting? I'm guessing 630 WPRO and 640 WNNZ. Also perhaps 650 WSM and 660 WFAN?

Yes, those are the four, but there is at least one more never-to-be-built AM 650 in eastern Canada. IIRC, if built, it would be in Pointe Claire QC, a Montreal suburb, 10 kW-D/2.5 kW-N DA-2, IIRC. Can't recall how many towers. As for WPRO, it's protected but that may be a consequence of the orientation of the existing towers (215 degrees true) and pattern symmetry. The minimum toward WSM at 250 degrees true (necessary to protect WSM's 0.5 mV/m 50%-skywave contour) necessitates a similar minimum at 180 degrees true. I don't know how much signal WSRO would have to send along that 180-degree radial to cause prohibited second-adjacent overlap (that is, overlap of 5 mV/m contours) with WPRO. WNNZ definitely requires protection and WFAN requires protection in the area to the west of Naragansett Bay. Because of the long salt-water path and the high population density, the FCC long-ago made it a policy not to count normally prohibited overlap between New England AMs and New York City AMs in the area to the east of the Bay. There is no such rule covering the area to the west of the Bay, however.

An interesting tidbit that I deduced from WSRO's app is that the new directional 62W night signal will protect WSM better than the current 9W ND night authorization. At 250 degrees true, the directional night signal will be equivalent to ~4.4W ND--roughly half the current ND night power. Also, based on WSRO's current PSSA, a new PSSA for directional operation between Framingham sunset and Nashville sunset should be possible. The maximum for such authorizations is 500W. I don't know whether the FCC will allow WSRO that much post-sunset power, but something more than the 62W night power should be permitted during that approximately one-hour period each evening (duration varies from month to month).

 

[Laurence Glavin]

With some (if not most) directional AM patterns, there isn't just the fact that the signal in a given protected direction is comparable to a non-directional station with 'x' watts, but that waves along that radial may be so out of sync with each other that even where the signal can expect to be heard, the audio is distorted. One day I was in western Massachusetts not-on-the-pike but on route 20 if I recall correctly. I had on WHYN-AM 560, and just as it began to fade as I drove west, I also noted that it sounded like a SW station from very far away. I kept it in on for a while and this effect persisted until WHYN-AM completely faded. On route 128 in the Waltham area, there's a point where WEZE-AM 590 not only weakens but becomes heavily distorted for a hundred yards or so.

 

[DanStrassberg]

With some (if not most) directional AM patterns, there isn't just the fact that the signal in a given protected direction is comparable to a non-directional station with 'x' watts, but that waves along that radial may be so out of sync with each other that even where the signal can expect to be heard, the audio is distorted.

True in the case of patterns with deep minima. In my experience, the most glaring example is WSNR/620 licensed to Jersey City NJ. This station first signed on in 1947 running five kW DA-2 as WVNJ Newark (a call sign that has since migrated elsewhere). WVNJ's transmitter and five-tower in-line array (with a center tower that was taller than the other four) was far west of Manhattan in (if memory serves) the community of Springfield NJ. The patterns were narrow tear-drops. Nevertheless, thanks to a low dial position and good soil conductivity in northern NJ, the station did a decent job of covering New York City's five boroughs. Much more recently, the station lost the Springfield site and was forced to move closer to Manhattan. The current site is adjacent to that of WLIB 1190. The array at 620's current site is still a five-tower in line and the patterns are still narrow tear-drops but now, the three middle towers are taller than the other two. Because of the move eastward the axis of the line of towers had to be rotated clockwise a few degrees; the station is incredibly hemmed in by such stations as WIP, WICC, and even WPRO. Day power had to be reduced to 3 kW, although night power was increased to 7.6 kW. The forced move was pretty much of a disaster. About the only places where the station delivers an undistorted signal are in Jersey City, the new CoL, Brooklyn, and southern Manhattan--locations that are essentially dead-ahead of the patterns.

Woes like those of WSNR should not afflict WSRO; its pattern minima will not be especially deep. The reason is that the array, having originally been designed for almost twice the frequency, uses towers that are electrically too close together (42.8 degrees). It would have been foolish to attempt to obtain deep minima from such closely spaced towers; the array would simply not have been very stable. Moreover, the history of the site tells us that no attempt to modify the towers in any way (for example, to alter the spacing between them) would have passed muster with the Framingham Zoning Board. And anyhow, Langer was no longer interested in spending a fortune on WSRO. (Several years ago, he gave up his quest to increase the power to 5 kW using a six-tower array in Wrentham--almost in Rhode Island).

 

[chrish]

890 WAMG has some ugly distortion problems off the back of the pattern as did the old WPDQ 600 bofore they removed two of the five in line towers and dropped night power, few places on the west side of the night pattern were listenable at all. When the site was built very sparse population in these nulls but I'm sure that has changed drastically.

 

[DanStrassberg]

890 WAMG has some ugly distortion problems off the back of the pattern as did the old WPDQ 600 bofore they removed two of the five in line towers and dropped night power, few places on the west side of the night pattern were listenable at all. When the site was built very sparse population in these nulls but I'm sure that has changed drastically.

During the daytime, WAMG's day pattern, which is deeply nulled to the north to protect the first-adjacent in Nashua (and by pattern symmetry, similarly nulled to the south, which helps in protecting WCBS), exhibits wicked distortion along Route 2 near Concord MA. The day pattern has a decent lobe to the west, however, and in the listening I did around Worcester a few years ago, I did not notice distortion there. However, WAMG, like WSNR, uses a five-tower in-line array to produce narrow teardrop patterns, though you might call the day pattern a narrow figure eight (lying on its side). The newer 6-kW night pattern is fatter than the day pattern or the old 3.4 kW night pattern and, in addition to the main lobe to the east, has a pair of narrow lobes, one to the northeast and, by pattern symmetry, one to the southeast. I believe that the night pattern produces wicked distortion in Wayland in the null between the main lobe and the northeastern secondary lobe.

 

[fybush]

True in the case of patterns with deep minima. In my experience, the most glaring example is WSNR/620 licensed to Jersey City NJ. This station first signed on in 1947 running five kW DA-2 as WVNJ Newark (a call sign that has since migrated elsewhere). WVNJ's transmitter and five-tower in-line array (with a center tower that was taller than the other four) was far west of Manhattan in (if memory serves) the community of Springfield NJ.

Livingston NJ, actually...and the current WSNR array in Lyndhurst, just like the old Livingston array, has just the one taller tower in the middle (90 degrees for the center tower, 60 for the two shorter ones on each side).