Is 630 an old "regional" channel or a shared old "clear channel"? Who are they protecting in the daytime. I think there is a 630 in St Louis KJSL. IIRC the WV station WJAW St. Marys was not around in the 1970's. The Canadians should not be bothered in the daytime. WMAL is in DC, I do not think any AM signal could go that far in the daytime with the hills in West Virginia messing with the ground conductivity. Wouldn't a 1000 watt non directional daytime have worked just as well in the 1960's and 70's. I know the night pattern will have to stay the same.
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WLAP has a signal west of Lexington
- Thread starter radiorob2.0
- Start date
Are they protecting 620 in Louisville?
Which was "first"? If my limited understanding of the FCC is correct, usually the "new" station has to protect the existing station.
From my memory. WLAP came to 630 from 1450 about 1953, I believe. WLAP protects the Non Directional 620 in Knoxville, TN which was on 620 long before WLAP moved to 630. The Knoxville station can be clearly heard in SE KY during the day. WLAP also protects the 630 in St. Louis which was around in the early days of radio long before LAP was on 630. Also the 630 to the east in Washington, DC gets protected. There is a 630 in Southwestern Ontario which probabaly also gets some protections as you can hear BOTH WLAP and the Ontario 630 in NW Ohio mixing during the day. There is also a 640 in Akron, OH which has also been there a long time which is probably why they have the deep null to the Northeast. These are just some of the reasons for the really crazy patterns they have.
I doubt the 620 in Louisville came into play when WLAP first moved to 630. I don't think it was on 620 back in 1953. Later on, someone probably figured they could squeeze Louisville's 620 in by taking advantage of WLAP's sharp null to the west to protect the St. Louis 630. If you look at the Louisville 620's daytime pattern, it is clear they are protecting WLAP.
I doubt the 620 in Louisville came into play when WLAP first moved to 630. I don't think it was on 620 back in 1953. Later on, someone probably figured they could squeeze Louisville's 620 in by taking advantage of WLAP's sharp null to the west to protect the St. Louis 630. If you look at the Louisville 620's daytime pattern, it is clear they are protecting WLAP.
secondchoice said:
It is/was a regional channel, currently in FCC records, it shows:
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Don't know what the regulations relative to WLAP are these days:
Do recall seeing & using the original protection contours. Seems in the early 1970s that FCC kept close watch on compliance. Actual field strength measurements were made weekly at specific locations in the null regions. Those measurements were recorded in a log for FCC purposes, and for maintenance of the antenna array.
Code:
The comments below are speculation based on foggy memory :)Each null in the pattern corresponded to another station on-frequency (630 KHz).
There were five stations, I think?
Two stations to the west, one was in Missouri, (St. Louis probably?).
A station in Washington DC (probably WMAL).
Another station to the south, and one to the north (probably Canadian).
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Thoughts on why the protection?
Seems that those contours were established in the early 1950s.
Guess AM radio was much more important then, and there was considerably less interference in the AM radio band.
Frequency stability was more of an issue back then. No two stations were exactly on frequency. The regulations allowed some leeway (20 Hz?). Two stations assigned to the same frequency could beat (heterodyne), causing interference to each other at far greater distances than the audio (sidebands) could be heard.
BobOnTheJob said:
secondchoice said:
That is my understanding, although I have heard of some exceptions, where an older station did not fully utilize or enforce its protection and another gained (maybe something like squatters rights)
KR4BD said:
Thanks for your comments.
I started my lengthy speculation before I saw your post, and then became interrupted before actually posting it. Didn't look to see your comments until already posting.
You are probably right that some of the stations protected are adjacent channel.
There was a Lexington radio urban legend regarding WLAP. Even though they could have had a better signal to the west it was decided to utilize the essence of the night pattern to create the day pattern. The patterns are almost identical, the day pattern isn't as tight. As mentioned above WTMT took advantage of the gap and landed at 620 thus making it impossible for WLAP to expand the signal to the west. When the signal is compliant it collapses as you past Bluegrass Airport. During the day WLAP can pick it up better in Ft Wayne, Indiana than you can in Lawrenceburg.
An interesting irony between WVLK and WLAP's night pattern. From each transmitter site you can see the towers of the other but in both cases can't receive the station.
An interesting irony between WVLK and WLAP's night pattern. From each transmitter site you can see the towers of the other but in both cases can't receive the station.
radiorob2.0 said:
I've always thought it was a shame neither station was able to get to the 50,000 watt range back "in the day".
DJOnAStick said:
5 kw low on the AM dial is good. The old WIND in Chicago has "almost" as good daytime coverage as some of the 50KW's. IIRC WIND was a factor in Chicago Ratings in the 1960's and early to mid 1970's. Of course the RF back round noise seems worse on lower AM freq.s. IMHO it is best to have a directional pattern that is close coverage wise 24 hours if possible. I know this is not possible always, but having lived and now living "out side" the night time pattern of my favorite AM stations is a bummer at night.
secondchoice said:
WIND at 560 kHz, had to look it up
Yes, signals at the low end propagate better than at the top of the band.
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There is about a 3:1 frequency difference from the top to the bottom.
Not exactly related but:
Comparable to the ratios between high-band VHF (176-216 MHz) and UHF (470-698 MHz)
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Most daytime AM reception is via a "ground wave", it follows the surface of the earth. Different from line-of-sight (LOS) commonly spoke about regarding TV signals.
The ground wave is most affected by soil conductivity. Sea (salt) water has very good conductivity (5,000), omitting units.
Conductivity numbers below () are from FCC Map of Effective Ground Conductivity in the United States:
For brevity, the units are omitted:
The mostly rocky hilly soil in eastern KY has poor conductivity (2), Lexington and northward (~8), and most central and western KY (4).
The Illinois soil has better conductivity (8-15), but not great.
Looking at old reference book:
For soil of conductivity (5), a ground wave relative field strength at 50 miles {}:
Code:
- Frequency = 610 kHz: {0.45}
- Frequency = 1600 kHz: {0.044}That particular example indicates about ten (10) times stronger for a signal at 610 kHz vs a signal at 1600 kHz.
At closer distances, ,the relative field strength ratio becomes less, and it becomes greater at longer distances. Also, the effect is less pronounced in good conductivity soil, becoming near equal field strength for the conductivity of salt water.
Bottom line, 5,000 Watts at the low end of the band can provide a competitive signal.
DJOnAStick said:
Unless they moved from their regional class frequency it wasn't possible then and the crowded dial today won't allow either to upgrade substantially.
When WVLK signed on the original COL was Versailles (hence the "V" in the call letters). The main nighttime lobe goes over Versailles. Back in 1947 the nulls over Fayette County weren't an issue, that changed by the end of the sixties when the growth moved south where the nulls became an issue. Several things were considered, the most obvious was moving the tower site but that was cost prohibitive. If I remember correctly a study indicated the idea spot was a golf course. They did had a construction permit twenty years ago to increase nighttime power to 1600 watts utilizing the same pattern but that was left to expire. One crazy idea was to LMA nighttime programming on 630 and simulcast WVLK on two frequencies. The last attempt involved purchasing or LMAing (can't remember which) 101.7 Richmond for a simulcast. However the Kentucky Central meltdown canceled those plans. Ironically that came true years later as 101.7 moved to 101.5 and came under common ownership with WVLK.
Having just received a hard copy of:
WLAP - Through Sixty Years
By Lewis M. Owens
Copyright 1982
Now, realizing the document is available on the Internet:
http://www.lkyradio.com/WLAPhistory.htm
Related to this discussion, some quotes from Lewis Owens document:
WLAP - Through Sixty Years
By Lewis M. Owens
Copyright 1982
Now, realizing the document is available on the Internet:
http://www.lkyradio.com/WLAPhistory.htm
Related to this discussion, some quotes from Lewis Owens document:
As long as we're waxing poetic, here's a fun tidbit about WLAP when it was at 1450. The antenna site was located between Harrodsburg Road and Versailles Road. The road leading to the site was later named Beacon Hill Road because of the tower's beacon light and its location on a hill.
jry said:
Yes, that was the site when WLAP was at 1450.
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