• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

540 null

T

tanner

Since someone was asking about the 1060 null protection maybe someone can answer who 540 protects over Tampa Bay. According to their night time pattern map they should not be clear in Tampa. However, you can pick them up along I-4 with a grade A signal at night from downtown Tampa all the way into Orlando. However go 5 miles south of I-4 towards Mulberry south of Lakeland and they completely disappear.
The map is not consistent at all with their actual pattern. Back to previous question, why would they have a null over the Bay area during the day. if their pattern were non directional they would have a grade A signal all thru Tampa Bay, including St. Pete. It seems like they should be allowed to have a non directional day time pattern.
 
tanner said:
Since someone was asking about the 1060 null protection maybe someone can answer who 540 protects over Tampa Bay. According to their night time pattern map they should not be clear in Tampa. However, you can pick them up along I-4 with a grade A signal at night from downtown Tampa all the way into Orlando. However go 5 miles south of I-4 towards Mulberry south of Lakeland and they completely disappear.
The map is not consistent at all with their actual pattern. Back to previous question, why would they have a null over the Bay area during the day. if their pattern were non directional they would have a grade A signal all thru Tampa Bay, including St. Pete. It seems like they should be allowed to have a non directional day time pattern.
Click to expand...

WFLF-AM 540 has a directional daytime pattern in order to protect WAYR-AM 550 Orange Park (Jacksonville) and WQAM-AM 560 Miami, both 5kw stations, and both second adjacent frequencies to AM 540. WFLF's 1mv/m contour cannot overlap with WAYR nor WQAMs 1mv/m contour, and for that reason, WFLF 540 is directional during the day.

Night-time WFLF is protecting a station in Canada though the Canadian call letters escape me at the moment. For this reason, somehow, the six tower pattern from West Lake County, just South of Clermont, created a null over Tampa Bay. It's strange sometimes how AM signals bounce around, especially at night.

Mark Tillery,
Ocala, Florida
[email protected]
 
Please disregard the previous two posts from me. I was trying to edit my comment when the darn thing timed out on me. So, here goes for a third time.

I was the one who asked the question relating to 1060 Titusville because, honestly, I do not know what other stations WIXC is protecting during the day. I only know at night they send very little signal North so they can protect 50kw KYW-AM 1060 Philadelphia (or as some Philly locals like to refer to their fair city as Filthy-delphia)

To address your question relating to 540, I can best answer it this way:

WFLF-AM 540 has a directional daytime pattern in order to protect WAYR-AM 550 Orange Park (Jacksonville) and WQAM-AM 560 Miami, both 5kw stations, WAYR and WQAM first and second adjacent frequencies respectively to AM 540. WFLF's 0.5mv/m contour cannot overlap with WAYR 1mv/m contour, nor WQAMs 3.16mv/m contours, and for that reason, WFLF 540 is directional during the day. Ordinarily the effected stations are far enough away that no directional antenna pattern would be needed, however, in this case, WAYR is near salt water, and WQAM's towers is setting in the middle of salt water. Because of this, WAYR and WQAM 5mv/m, 3.16mv/m. 1mv/m and 0.5mv/m signals are carried along the Atlantic ocean well beyond the distance a 5kw signal would normally reach if the towers were over sand and no large bodies of water were near by. WFLF 540's signal blows well into the Atlantic where much of any overlap with either of the other two stations signals would take place although there are some places over populated areas that would also be affected.

Night-time WFLF is protecting a station in Canada though the Canadian call letters escape me at the moment. For this reason, somehow, the six tower pattern from West Lake County, just South of Clermont, created a null over Tampa Bay. It's strange sometimes how AM signals bounce around, especially at night. Welcome to the wonderful world of radio waves, electromagnitism and ever popular physics.

I hope this helps to explain why AM 540 operates with a directional antenna pattern and how the null over Tampa Bay was created.

Mark Tillery,
Ocala, Florida
[email protected]
 
540 protects Canada but the null toward Tampa Bay and south Polk County is more likely in place to protect the skywave signal of 540 in San Luis Potosi, Mexico over Mexican soil (which extends all the way around to Cancun, due south of the Panhandle).

I would think interference from the 530 in Turks and Caicos would also be a limiting factor for 540's nighttime signal. They do seem to compensate with a lot of compression after dark. You can hear them quite well in Eastern North Carolina after dark, though.

Do they still protect WDAK in Columbus (which went Class D a few years back)?
 
smedge2006 said:
540 protects Canada but the null toward Tampa Bay and south Polk County is more likely in place to protect the skywave signal of 540 in San Luis Potosi, Mexico over Mexican soil (which extends all the way around to Cancun, due south of the Panhandle).

I would think interference from the 530 in Turks and Caicos would also be a limiting factor for 540's nighttime signal. They do seem to compensate with a lot of compression after dark. You can hear them quite well in Eastern North Carolina after dark, though.

Do they still protect WDAK in Columbus (which went Class D a few years back)?
Click to expand...

I'm a 540/WGTO alum, and my recollection is that the frequency had been both a Canadian Clear and a Mexican Clear (back when such terminology was common), thus the nulls to both the north and southwest. I believe that Orange Park and Columbus were fit into GTO/FLF's pattern and not vice-versa, and that QAM is irrelevant as a second adjacency with ample separation. Likewise, the western lobe over Tampa Bay is a happy coincidence--not hurting anything, but not particularly intentional, either. A "leak," if you will. The goal was to burn up Orlando, which it does more-or-less. 40 years past the point when it would have been truly valuable, but still...
 
The Radio-locator map indicates a null. However, there is a grade A signal day and night in Tampa but it drops off quickly as you head over the 275 bridge to St Pete., day and night. Downtown Tampa is as if it were a local.
 
WFLF-AM 540 does have an impressive unlimited signal from Tampa through Orlando over to Melbourne. However, for some reason, WFLF has a CP to reduce night power from 50kw to 46kw with a slight pattern change. This "slight change" has resulted in the loss of Tampa, Lakeland and Winter Haven primary night service.

Mark Tillery,
Ocala, Florida
[email protected]
 
That CP has been in place for a couple of years. Why would a station want to go from a 4 to a 6 tower array during the day. It also would drop their distant signal out of South Florida. Also, a power reduction at night?. Seems pointless to me.

However, this is the story I've heard. Cheap Channel wants to combine WFLF and WQTM's tower array into one array and I guess WQTM's meet the needs better. However, 740 has a terrible signal everywhere except towards Brevard county. I was in the Villages last week and you could receive all these stations from Orlando better than 740 (580,950,990,1030,1080,1140,1600,1680) Yikes! Have they been broadcasting from the new array at all?

I guess this is how they do things at Cheap Channel.
 
jmtillery said:
WFLF-AM 540 does have an impressive unlimited signal from Tampa through Orlando over to Melbourne. However, for some reason, WFLF has a CP to reduce night power from 50kw to 46kw with a slight pattern change. This "slight change" has resulted in the loss of Tampa, Lakeland and Winter Haven primary night service.
Click to expand...

Unless it affected the populated areas of Orange, Osceola and Seminole counties, it likely was not a concern in redesigning the array.

Going 50 kw to 46 kw may, if the new towers are a little more efficient, not reduce the effective power at all. Remember, dropping to 12.5 kw would only reduce coverage by half.
 
tanner said:
That CP has been in place for a couple of years. Why would a station want to go from a 4 to a 6 tower array during the day. It also would drop their distant signal out of South Florida. Also, a power reduction at night?. Seems pointless to me.
Click to expand...

An 8% reduction in night power is only a 4% reduction in coverage, everything else being equal. As to the array, often more towers allow for elimination of sympathetic lobes (nulls the opposite side of the needed nulls). I've moved a two tower DA to a 4 and improved metro coverage by a significant degree.

However, this is the story I've heard. Cheap Channel wants to combine WFLF and WQTM's tower array into one array and I guess WQTM's meet the needs better.
Click to expand...

With the value of land, the maintenance costs of sites and other factors that were not significant a few decades ago when Orlando was much smaller, it's only logical that they would consolidate if they don't harm the metro 3-county coverage. Any other loss is not relevant.

However, 740 has a terrible signal everywhere except towards Brevard county.
Click to expand...

That's because it has a very different pattern and protection requirements, and is 200 kHz higher up the dial, too.

I was in the Villages last week and you could receive all these stations from Orlando better than 740 (580,950,990,1030,1080,1140,1600,1680) Yikes! Have they been broadcasting from the new array at all?
Click to expand...

The Villages is way outside the metro. And 740 has a severe day null towards Alachua County, likely to protect the fringe of WSB.
 
I was in St. Pete today and drove home after dark today back in Orlando. I did this every day for 2 months this summer and after dark 540 as stated before along the I-4 corridor had a local signal from exit 3 all the way into Orlando. However, tonight yje signal was very weak towards Tampa. Even as close as US 27 exit 55 the signal was fading in and out. Are they now operating from the new array? What was a clear and local signal in Lakeland now is not listenable. They in the past performed just as good as the local station in the books.
 
Doesn't WFLF have to protect 540 WDAK in Columbus, GA which would explain its east-west pattern?
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom