WCRB should become a B1 FM

[LA_Guy]

I haven't done the studies, but I believe that as a class B1 station, WCRB can move to Zion Hill-or even the old 100.7 site along Rte.2 in Waltham. The main spacing requirement is that it remain 14 KM (8.7 miles) from 1 Financial Center (IF to WERS). The old 100.7 site is 14.4 kM. Needham might also be possible-but now you're getting a bit too close to 99.1 in Plymouth.

Bear Hill in Waltham might also be a possibility, since B1 stations only need a 100 meter (328 foot) antenna.

Either of these sites would produce a MUCH better signal in Greater Boston then Wood Hill does now. They would have to do a city of license change-Somerville likely. Or, perhaps a Longley-Rice case might be made that Lowell still receives 100% city grade coverage.

Here's the predicted city grade and 1 mv/m service contours as a B1 from the old 100.7 site. Looks GREAT to me!

http://www.fcc.gov/fcc-bin/plotit?a...ue2=1&majroads=1&water=1&miscel=1&iwd=800&ht=

To see it best, click on "Circle Map on New Page"

 

[LA_Guy]

I stand corrected-the plotted service (outer) contour is the .7 mv/m contour-not the 1 mv/m one.

In any event, this signal is perfect for classical-it's strongest in the western $uburb$ while still smokng downtown.

It fills in the 495 perimeter almost perfectly.

Now THIS is a signal perfect for sports-too bad Entercom!

This might also possibly allow for some interesting FM allotments up north too.

 

[DanStrassberg]

I haven't done the studies, but I believe that as a class B1 station, WCRB can move to Zion Hill-or even the old 100.7 site along Rte.2 in Waltham. The main spacing requirement is that it remain 14 KM (8.7 miles) from 1 Financial Center (IF to WERS). The old 100.7 site is 14.4 kM. Needham might also be possible-but now you're getting a bit too close to 99.1 in Plymouth.

Bear Hill in Waltham might also be a possibility, since B1 stations only need a 100 meter (328 foot) antenna.

Aren't the maximum power and antenna height for a B1 the equivalent of 25 kW @ 100m AAT? I know the FCC has curves that show that as HAAT increases, the ERP for equivalent coverage does not decrease exactly in proportion to the square of the ratio of antenna heights. Still, HAAT^2 is the best I have to go on. By that measure, a B1 with HAAT of 150m (which I think happens to be the exact HAAT of the tower at 75 Concord Ave in Lexington--the old 100.7 site) would be 11.11 kW. If I haven't got dB power and dB voltage confused, that 4.5:1 ratio is just little more than 6 dB. (Or is it a little more than 12 dB?)

Anyhow, I'll take your word that, from either Zion Hill or Concord Ave, the 99.5 signal would be OK for the classical format in most areas within 495. How would it compare with the downtown-Boston full Bs (104.1, for example) in Worcester? (No, I haven't forgotten that Worcester is outside of 495.) I've heard that 104.1's signal is not really acceptable in Worcester, but 98.5, which is in Newton or Needham, does have an acceptable signal in Worcester.

Also, am I right that the FCC would NOT accept an application for 99.5 to move to Concord Ave or Zion Hill with a directional antenna that limited the signal to the east and south to what a nondirectional B1 would produce but would allow a full B signal to the west and north?

 

[LA_Guy]

I haven't done the studies, but I believe that as a class B1 station, WCRB can move to Zion Hill-or even the old 100.7 site along Rte.2 in Waltham. The main spacing requirement is that it remain 14 KM (8.7 miles) from 1 Financial Center (IF to WERS). The old 100.7 site is 14.4 kM. Needham might also be possible-but now you're getting a bit too close to 99.1 in Plymouth.

Bear Hill in Waltham might also be a possibility, since B1 stations only need a 100 meter (328 foot) antenna.

Also, am I right that the FCC would NOT accept an application for 99.5 to move to Concord Ave or Zion Hill with a directional antenna that limited the signal to the east and south to what a nondirectional B1 would produce but would allow a full B signal to the west and north?

Correct. The FCC will not allow ANY IF short spacing-and the Lexington Ave site barely makes the IF spacing as a B1. You are correct about running 11 kW from the top of the tower-but I'm not sure I'd do that. I'd probably put the antenna right at 100 meters and run the full 25 kW-or certainly not derate any lower then 20-22 kW. Reason is that you want the power for building penetration-you have to penetrate those skyscrapers and also also overcome the intermod from the Pru. That extra 40% field would help a lot to do that. I'd pick a spot on the tower that's 15 feet above a guy level as close to 100 meters AAT as I could.
I'd also use a 2 or 3 bay half wave spaced Shiveley 6810 antenna.

Running 25 kw from this site would result in a better signal downtown then many off-Pru stations. The reason is some of those rte 128 antenna farm stations run ERPs less that 25 kw-and to penetrate the downtown buildings you need line of sight and raw power. This site has both-even at 25 kW. It's also a bit closer to downtown then they are. Remember that downtown is near sea level, so you're actually going to be about 150 meters AAT in that direction from the lower antenna anyway.

Or, ideally, I'd install two transmitters and antennas, license the lower one (at 100 meters and 25 kW) as an auxiliary and run my aux system during the day and the main 11 kw pole mounted at the top of the tower at night. That way you get the best of both worlds-the building penetration during the day and the bigger service contours at night. As long as you're on the main more then half the time it's completely legal. You can also use the side mounting to blow even more power towards downtown with the auxiliary-and then optimize the pole mounted antenna on top to be as circular as possible.

Hmmm..I wonder if we should bill WGBH for this free consulting that will wind up more then doubling the value of their station if they do it?

 

[DavidZ]

Anyhow, I'll take your word that, from either Zion Hill or Concord Ave, the 99.5 signal would be OK for the classical format in most areas within 495. How would it compare with the downtown-Boston full Bs (104.1, for example) in Worcester? (No, I haven't forgotten that Worcester is outside of 495.) I've heard that 104.1's signal is not really acceptable in Worcester, but 98.5, which is in Newton or Needham, does have an acceptable signal in Worcester.


[/quote]

Dan, I have never had trouble getting 104.1 in Worcester (home or car). Back in the day, WBCN was always a preset for me.

 

[wcozBoston]

How high above the ground is the old WHUE 100.7 Lexington tower? How high is the top of the tower above sea level?
Would this site have to protect 99.7 in Rhode Island using a D.A.? Last question: Could WPLM move closer to town?

 

[chrish]

Recently I had du Triel and Rackley do the B-1 study for 99.5 looking at Mt. Zion and
the old WCOP-FM tower, it was a bit shy for Zion and out of the question for Lexington.
Also would not work on the middle tower of the WRKO array.

 

[chrish]

Re: WCRB should become a B1 FM correction

I just pulled up the du Triel and Rackley study and 99.5 can go on the center tower of WRKO, it just makes it by a 1/4 mile or so, no further south in Burlington than 128/I95

 

[LA_Guy]

What's the limiting factor from Waltham, Chris? It isn't WERS or WEAN-FM. It isn't WQRC. Is it WPLM?

Looks to be WPLM. Short spaced by 4 miles-BUT not really that much, as WPLM isn't a full class B station!

 

[DanStrassberg]

Looks to be WPLM. Short spaced by 4 miles-BUT not really that much, as WPLM isn't a full class B station!

By my calculations, moving 99.5 closer to WPLM would work technically (WPLM is equivalent to ~38 kW @ 150M AAT), but based on what I've heard from a supposedly knowledgable person, such a move would not pass muster with the FCC. WPLM must be protected as if it had Class B maximum facilities even though its short-spacing to at least one station (WPLR) and maybe others prevents WPLM from getting Class B maximum facilities. I suppose the FCC's reasoning might be that WPLM could increase its tower height and install a DA that would improve its signal to the north (Boston). Of course, the tower height increase would mess up the AM DA, although perhaps the top part of the newly taller tower might be skirted, with the skirt driven out of phase with the current in the tower structure so that, at 1390 AM, the tower would behave as it it had not been lengthened.

Unless the ratchet rule is repealed (DL&R and some other consulting engineering forms have petitioned the FCC to do just that), top mounting the 99.5 antenna on WRKO's center tower, would necessitate skirting the top-mounted FM antanna in the same way because the FCC would regard the increase in the tower height as a signifcant change in WRKO's facilities.

 

[DanStrassberg]

It would be interesting to know how much WPLM's signal would improve in various parts of the Boston market if it were to increase its antenna height to the Class B maximum and install a DA that protected WPLR and any other stations to which it night be short-spaced. I believe that there is a 99.1 somewhere in NH, but doesn't that station protect WPLM just as if its signal to the north were equivalent to 50 kW ERP @ 150m AAT?

 

[WLYNWAZNgm]

the Concord Ave., Lexington site

WAZN is on the 3-tower (self-supporting) array there, along with the 1150.
The guyed tower - lights on it, recently repainted - to the best of my
knowledge, has NOTHING on it. I would love to see a ham repeater up there!

 

[LA_Guy]

Looks to be WPLM. Short spaced by 4 miles-BUT not really that much, as WPLM isn't a full class B station!

By my calculations, moving 99.5 closer to WPLM would work technically (WPLM is equivalent to ~38 kW @ 150M AAT), but based on what I've heard from a supposedly knowledgable person, such a move would not pass muster with the FCC. WPLM must be protected as if it had Class B maximum facilities even though its short-spacing to at least one station (WPLR) and maybe others prevents WPLM from getting Class B maximum facilities. I suppose the FCC's reasoning might be that WPLM could increase its tower height and install a DA that would improve its signal to the north (Boston). Of course, the tower height increase would mess up the AM DA, although perhaps the top part of the newly taller tower might be skirted, with the skirt driven out of phase with the current in the tower structure so that, at 1390 AM, the tower would behave as it it had not been lengthened.

Unless the ratchet rule is repealed (DL&R and some other consulting engineering forms have petitioned the FCC to do just that), top mounting the 99.5 antenna on WRKO's center tower, would necessitate skirting the top-mounted FM antanna in the same way because the FCC would regard the increase in the tower height as a signifcant change in WRKO's facilities.

Wrong.

You can do a 73.215 short space to WPLM, based upon its maximum contour. I'm not sure how much it helps though.

Zion probably is too short spaced to WERS.

 

[DanStrassberg]

Zion probably is too short spaced to WERS.

Ahh, but that may not be true of the 93.7 tower in (I think) Peabody! From that site, 99.5. with full B facilities, might not have any prohibited overlap of actual contours with WPLM. However, I've been told by several people that the absence of prohibited overlap wouldn't make any difference to the FCC because the distance from Peabody to Plymouth doesn't meet the B-to-B second-adjacent spacing minimums. To relocate to Peabody, 99.5 would have to downgrade to B1. The 4.5:1 power reduction seems way too steep a price to pay for that move because the signal in Boston wouldn't improve very much, if at all. 99.5 would be better than WKAF, but not really competitive with the full B signals in the market.

 

[LA_Guy]

The tower in Peabody is still short spaced with WOLM as both a class B and a B1. Trouble is, the FCC's second and third adjacent rules vary very little between classes of stations. Note the table here:

http://www.fcc.gov/mb/audio/spacing/
On second and third adjacents channels,

A-B spacing is 69 km
B1-B is 71 and
B-B is 74 kM

Here are the 74 and 69 M circles:

http://www.fcc.gov/fcc-bin/plotit?a...ue2=1&majroads=1&water=1&miscel=1&iwd=800&ht=

Click on 'redraw the map' if it doesn't automatically display.

As can be clearly shown, the Peabody site doesn't work.

Lexington (rte 2) is barely short spaced as a B1-it might fit based upon 73.215.

The WRKO towers do fit as a B1.

I'd go for the Lexington site and try to get a waiver because the tower is already there and the short spacing is 'de minimus'.

 

[DanStrassberg]

A-B spacing is 69 km
B1-B is 71 and
B-B is 74 kM

Here are the 74 and 69 M circles:

http://www.fcc.gov/fcc-bin/plotit?a...ue2=1&majroads=1&water=1&miscel=1&iwd=800&ht=

I could easily believe that the two circles are 71 and 69 km. I could even believe 74 and 71 km. But I can't believe 74 and 69 km. 74/69 = 1.072. I just can't believe that the larger radius is 7.2% larger than the smaller one. Another siite that looks like it would work is Stiles Hill!!! (WAAF). WAAF would probably do OK in Boston if it didn't have to protect WFCC. Even though downtown Boston is on the skirt of the null that protects WFCC, the signal toward downtown must be the equivalent of only about 1/4 of the power in the large arc to the northwest. I'm assuming that if the spacing exceeded that shown by the outer circle, no null toward WPLM would be needed.

 

[DanStrassberg]

I think 99.7, the first-adjacent Class A in Wakefield-Peace Dale RI, is the stopper. It's 77.7 miles from WCRB's current site but is way closer to all of the sites we have been discussing. It's only 53 miles from Stiles Hill--albeit almost due south. The 99.7 pattern has a deep null to the east, I assume to protect WPLM.

 

[necrat123]

I think 99.7, the first-adjacent Class A in Wakefield-Peace Dale RI, is the stopper. It's 77.7 miles from WCRB's current site but is way closer to all of the sites we have been discussing. It's only 53 miles from Stiles Hill--albeit almost due south. The 99.7 pattern has a deep null to the east, I assume to protect WPLM.

The center of the null points right at the WQRC transmitter site. So they could be protecting WPLM but I would put more money on protecting 1st adjacent WQRC.

 

[DanStrassberg]

I think 99.7, the first-adjacent Class A in Wakefield-Peace Dale RI, is the stopper. It's 77.7 miles from WCRB's current site but is way closer to all of the sites we have been discussing. It's only 53 miles from Stiles Hill--albeit almost due south. The 99.7 pattern has a deep null to the east, I assume to protect WPLM.

Or did I mean 77.7 km and 53 km? 77.7 km would be ~48.5 miles and 53 km would be ~33 miles. I think those distances sound more reasonable, but I'm not sure.

 

[4CX1000A]

I can't imagine that a company with Greater Media's passion for good engineering wouldn't have moved 99.5 if there was a better site. Greater has never been shy about moving stations to optimize their coverage of the market; most recently they moved 102.5 from the FM128 tower to that of WBZ-TV. If there were a better place to put 99.5, I suspect it would be there today.