WXKS-AM Application

[Laurence Glavin]

I had a suspicion that after the three-way operation at 750 Sawmmill Parkway, Newton was installed one or more of the outlets there might want to start tweaking their patterns. The first off the block is WXKS-AM 1200 which wants to make changes to their daytime pattern. Specifically, they want to go from three towers to four, which would seem to tighten their pattern but why would they want to do that? Can a switch from three to four towers actually LET OUT their pattern a bit?

 

[DanStrassberg]

The use of four towers instead of three will somewhat alter the shape of WXKS (AM)'s day pattern; it will NOT tighten the pattern, however. Perhaps CCU still intends to switch on IBOC. If so, this tweak may reduce the fallbacks to analog in some populous places--Framingham, Lowell, and Nashua, for example--assuming that these places even get a useful IBOC signal. Another interpretation is that this application was prepared when the station was still broadcasting in Spanish and wanted to improve its daytime signal in Lawrence. The improvement in Lawrence will be far from profound--but might be noticeable to determined radio geeks with good receivers. Yet another interpretation is that CCU wanted to do what it could to better match WXKS's coverage to WRKO's. Based on the coverage maps, I suppose you could say that this change will accomplish that objective if you think that increasing the signal from 2 mV/m to maybe 3 mV/m in places where WRKO delivers 40 mV/m is a worthwhile undertaking.

In any event, with this change, WXKS would become the second of the three stations in the triplex that uses more towers by day than by night. WRCA uses five towers by day and four by night. WXKS would use four towers by day and three by night. WUNR (the only one of the three stations that operates DA-1) uses all five towers all of the time.

 

[necrat123]

Another interpretation is that this application was prepared when the station was still broadcasting in Spanish and wanted to improve its daytime signal in Lawrence.

No, that's not it. The engineering exhibit was prepared by DLR on September 13, 2010.

 

[DanStrassberg]

Another interpretation is that this application was prepared when the station was still broadcasting in Spanish and wanted to improve its daytime signal in Lawrence.

No, that's not it. The engineering exhibit was prepared by DLR on September 13, 2010.

Just because they signed off on the application and filed it that recently doesn't mean that they began work on it that recently. Work could easily have begun many months ago. My impression is that, once the consulting engineer does the work, he gets paid only when the FCC accepts for filing the application he was engaged to work on. Of course, that might not be be the case--but I think it is, and if it is, it means that the project could have been started before WXKS dropped the SS music and the WKOX calls.

 

[necrat123]

I understand your point, but I think this application is newer than that. I wouldn't be suprised however, if this was planned around the time they dropped the simulcast on 1430 for the talk programming. That would make more sense to me anyways.

 

[Laurence Glavin]

The application was approved in the FCC Actions for January 7th.

 

[DanStrassberg]

The application was approved in the FCC Actions for January 7th.

I wonder whether the deletion of an unbuilt AM 1200 in Highland NY (Poughkeepsie) had anything to do with CCU's tendering this app. I never checked to see how close the proposed Highland station's 0.025 mV/m contour came to WXKS (AM)'s 0.5 mV/m, but I could believe that the contours almost touched. If so, with the Highland station gone (before it even appeared), these improvements, like WWZN's relaxation of its non-CH day pattern a few years ago(taking advantage of the deletion of WNLC) provided a nice way of improving the daytime coverage somewhat while keeping other stations from moving in and encroaching on the coverage. Indeed, I think that, had CCU not made this move, someone might have tried to drop an AM 1200 into the Capital District (Albany/Schenectady/Troy) market. With WTLA 130 miles or so to the west, such a station would have had to be shoehorned in, but the WGDJ (1300) site, with its six towers, might have permitted the design of a suitable array, while avoiding the complications of new tower construction.

 

[dumber than a box of hair]

From looking at the two daytime patterns side-by-side:

1) They're trading some field strength toward Boston for better coverage of the North Shore.

2) They're creating a null where they had a minor lobe before, to the southwest (at apx. 250 degrees true).

3) Coverage to the south of the site will also be a bit better.

Not sure if/how much it will help, because it won't be a drastic change in field strength in any direction.

 

[DanStrassberg]

2) They're creating a null where they had a minor lobe before, to the southwest (at apx. 250 degrees true).

There is indeed a shallow minimum in the new pattern at 250 degrees true, which currently lies at the center of a minor lobe. But the ID (inverse-distance) field at the new minimum is almost exactly the same as that of the current ID field at the same azimuth: 920 mV/m @ 1 km. IOW, everywhere else to the west-southwest, the signal is stronger (albeit not markedly so), but at 250 degrees it is neither stronger not weaker. It appears to me that the new pattern RMS must be greater than the old. I suspect that the new pattern gains some efficiency by reshaping the vertical radiation pattern to reduce the high-angle skywave. Such improvements can sometimes be accomplished by modifying the off-axis pattern minima. Use of an off-axis tower (along with--I'd wager--extensive computer simulation) apparently enabled such an improvement in this case.

 

[nd2023]

What is the point of installing an IBUZ machine at an AM station now? Nobody listens to AM in HD. Just simulcast it on an FM HD.

 

[DanStrassberg]

It appears to me that the new pattern RMS must be greater than the old.

More research shows that my conclusion was incorrect. The new pattern's RMS is ever so slightly lower than that of the current day pattern (2305 mV/m @ 1 km for the new pattern vs 2345 for the current day pattern). You'd never know it from looking at the contour maps, though. The contours are further from the antenna system in almost every direction, suggesting that the conductivities used to predict the existing pattern were lower than the actual conductivities. That doesn't happen very often.

At 250 degrees, however, I was correct. The new minimum at 250 degrees is 976 mV/m @ 1 km whereas the minor lobe at 250 degrees in the existing pattern is 920.

 

[Laurence Glavin]

I was listening to the station for a while, to hear the right-wingers' comments about events over the weekend. ( Glenn Beck is issuing a challenge to The President!) Anyway, an announcer is came on and alerted the few thousand listeners at any time, that technical changes are about to be made at "Rush Radio 1200", and to bear with any interruptions that may occur. He falsely claimed that "Rush Radio 1200" is Boston's newest 50,000-watt station. Oops. (WQOM may be a Natick station, but then WXKS-AM is a Newton station...so there.)

 

[raccoonradio]

Looked up WQOM on radio-locator; it said they were "currently off the air" (wrong) but did say that under the CP (I think they're using this pattern now), AM 1060 is 50kw days, 2500w nights

I noticed WXKS came in fairly well this morning here in Beverly. Did I hear they were sacrificing
signal toward Boston to beef up North Shore and South Shore reception? (Before, 1230 would cause problems for WXKS, formerly WKOX, when WESX was broadcasting from Marblehead. Of course awhile back they changed the transmitter to Lynn, with the city of license being the mighty
Nahant (all of 3,900 citizens...no traffic lights...no high school...)

 

[DanStrassberg]

an announcer is came on and alerted the few thousand listeners at any time, that technical changes are about to be made at "Rush Radio 1200", and to bear with any interruptions that may occur.

Well, the first part of the part of the changes are more likely to affect WRCA and/or WUNR than WXKS. The tower that is new to WXKS (tower #4, the western tower in the southern row) has not been used at all by WXKS but is used by WRCA and WUNR 24/7. Even after the changes are complete, WXKS will not use tower #4 at night. I would think that the ATU mods would be the first to be made. Conceivably, WXKS could continue to operate normally while a new ATU is being installed at the base of tower #4. After that, WXKS's three-tower day phasor probably needs to be swapped out. With three high-powered stations using the array, that part of the job could be tricky.

 

[DanStrassberg]

Did I hear they were sacrificing signal toward Boston to beef up North Shore and South Shore reception?

Yes, but you can't tell from the new coverage maps, which show almost identical coverage of Boston under both setups. The signal toward downtown Boston will be reduced but quite possibly not to a degree that anyone will notice. If you're in downtown Boston and you tune in WWZN when they switch from their CH pattern to their day pattern, can you tell that the signal got a little weaker? If so, you may notice the change in WXKS's day signal downtown.