I should've been more clear. When you said WMFN was off, I checked 640 and indeed WMFN wasn't there. I immediately tried for WOI, but I couldn't make it out. There was something there at the noise level, probably WOI, but WSCR's splatter wasn't helping me dig it out even when I tried to null it. I used to hear WOI during the day at this location before WMFN signed on. I did hear WMT when I checked.
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Wmfn 640
- Thread starter cyberdad
- Start date
I should've been more clear. When you said WMFN was off, I checked 640 and indeed WMFN wasn't there. I immediately tried for WOI, but I couldn't make it out. There was something there at the noise level, probably WOI, but WSCR's splatter wasn't helping me dig it out even when I tried to null it. I used to hear WOI during the day at this location before WMFN signed on. I did hear WMT when I checked.
I think the point is to build SOMETHING to show that progress has been made to building it. The final towers are supposed to be different heights and have some type of top loading. Maybe somebody can take pictures with their cell phone? I suspect it is built to the lowest guy support level.
I do think this is a facility worth building. It's a lot better potential facility than many other area AMs.
The towers really did look incomplete. Almost like stubs with the tops cut off. There was no activity going on when I drove by, which was around 3 or 3:30 in the afternoon. And bear in mind that I only caught a glimpse for a few seconds as I was passing the site on I-57 at full highway speed. My first thought was that local WKAN (1320) might be up to something in terms of an upgrade or some other reason to move their transmitter location.
And, yes, I agree that it's probably a facility worth building. Birach....the owner....has a track record operating brokered ethnic stations in bigger markets. Odds are they know what they're doing.
@Radioman, thanks for clarifying. WOI's signal was really pretty much spent when I heard it here yesterday. The way I was able to ID it at first was to tune to WILL and establish that WOI had the same NPR programming. (A talk show hosted by a man and woman).
I'm 27 miles from Zeeland, MI. and first noticed their absence on February 1st. With WMFN out of the way, the channel is now open for DX here on my South antenna. New 640 logs include Cuba (heard often) and Akron's WHLO, which I caught briefly, but hasn't been heard since.
Kilokat, have you heard KFI recently? If so is it tougher than it used to be? Here in Northern Illinois I used to get it regularly, but in recent years I haven't heard it at all even when WMFN wasn't an issue. Just wondering if KFI's signal has been degraded for some reason.
I'm planning to check 640 more frequently in order to see if/when the "new and improved WMFN on steroids from their new home" turns up. Until they do, I'll see if I can snag KFI. I'm not particularly optimistic. Especially since I've whiffed my last few years trying for KNX. But 640 is less crowded around here than 1070, so who knows.
KFI seemed a little less common here during the 2016-2017 winter DX season as compared to past years. It's difficult to say if this is due to their facility or just poor propagation. The best time for me to catch them has always been during the morning at sunrise in the early Fall.
I have also found that during the fall pre-sunrise was the best time for me to catch KFI. However, the last few years I haven't heard them. Maybe it's timing or as you said poor propagation.
Bumping this up from a week ago.....
I tried 640 a couple of times again this week, each about an hour before sunrise, with KFI as the target. 640 is one of the quieter channels around here at night, especially with WMFN off, so if KFI is present at all, the chances of it getting "lost in the mud" are mitigated.
That notwithstanding, I was not successful. On each occaasion it was WOI, weak but on top. I heard what sounded like sports talk in and out of the background but couldn't ID it. My guess is Oklahoma City because I've heard that station here before, although not recently. I think their night pattern (basically north-south) is different from what they were using during their top-40 days as WWLS. There's also a sports talk station on 640 in Tennessee, but I think that one is only 500 watts at night with a pattern that doesn't favor me.
What do you guys think?
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I've found that even when conditions are good KFI was much tougher to hear this time of year. Having said that I must ask did you check general conditions to the west?
When trying for the west coast I usually check to see if KOA & other stations from the west are above/below normal. In recent times KFI has been missing even during the fall & winter when it was much easier to hear. I still suspect that for some reason KFI's signal towards the midwest is not what it once was although I have no proof of that.
I've found that even when conditions are good KFI was much tougher to hear this time of year. Having said that I must ask did you check general conditions to the west?
When trying for the west coast I usually check to see if KOA & other stations from the west are above/below normal. In recent times KFI has been missing even during the fall & winter when it was much easier to hear. I still suspect that for some reason KFI's signal towards the midwest is not what it once was although I have no proof of that.
radioman148, after KFI's tower was hit by an airplane, even though it was there first before a nearby airport, the FAA made them reduce the height. Although the heavily modeled sectionalized replacement tower has the same efficiency and nearly identical vertical radiation characteristic at all elevation angles, I wonder if the old tower top peeked over some mountaintop that it no longer peeks over. Regardless of theory, line of sight probably affects the signal in some way. I've seen this happen with FMs when arcane rules for grandfathered overpowered facilities were forced to reduce height, for example, because they lost their TV tower TL due to digital antenna aperture accommodation during the transition. But that is part of the FM prediction method. The AM skywave propagation model used doesn't account for that, though probably an ideal, more detailed model would.
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The timeline has the tower being felled in 2004, after which it was on a quarter-wave aux antenna for a few months at 25 kw, and then on the center tower of the old KRKD-1150 site until late 2008 when the tower was rebuilt as you indicate.
From 2008 to present, about 8 years, there have been no site changes.
The top hat is a very traditional flat-top in a hexagonal shape. It is not the more widely used system of using the topmost guys down 50 to 100 feet as a top.
My theory, David, is that the top part of the old tower peeked over a terrain obstruction that the new physically shorter tower doesn't, and that part of the signal is blocked from reaching the ionosphere. It no longer contributes to the skywave. Regardless of things being theoretically identical, Geometry is Geometry, Physics is Physics. The terrain obstruction is probably nearby and refraction and diffraction over it doesn't compensate for it.
I thought about the newer KFI tower being a factor in my lack of reception of KFI here. I don't know how valid that theory is, but I do know that KFI has been a much tougher catch here in recent years.
The only terrain obstructions are very far away from the Buena Park location of the KFI tower. It is very, very flat land for many miles, not even low hills. This is the general area in which Disneyland is located. And any eventual blockage would be at a very low angle from the site.
And the skywave relevant to Chicago would be at a very low angle.
How much higher and how far away are the mountains? Here in SE Michigan, we have a 600 foot terrain ridge 20 miles away and it acts as the practical limit for many signals, and particularly with all the new cochannel translators and new Canadian stations. People think it is much further to stations on the other side than it really is. Yes, I know it's FM, but look how the F(50,50) model would completely ignore this ridge. A model for AM skywave may similarly ignore such factors. A signal, particularly AM, can bend around obstructions, or reflect from the ionosphere, but it can't go through the earth or hills. I did also hear of an AM proof of a three tower array where the center tower was much higher, and the pattern "disappeared" and behaved nondirectionally at the distance where the top of the center tower was LOS and the two end towers were shadowed. The pattern reappeared where the higher tower also became shadowed. Just saying the AM model may not explain everything.
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Well, besides hills and mountains, the terrain rises in several shelf increments. The Inland Empire area is about 900 feet higher on average, and the San Gabriel Valley area is about 600 feet higher. Then there are mountains mostly, on the Chicago path, in the 50 or so mile distance... but some are as high as 10,000 feet and the average would be in the 5,000 to 6,000 range.
If we are talking single, low angle hops, then those might be significant. If we are talking about the probably more likely multiple hops, not so much.
If we looked at the top of the old tower and top of the new tower, and see what the difference is in the shadowed and LOS areas, it might give some insight. Sometimes it's amazing what a small change in height can do.
If we take the arctangent of 1/50 and 2/50, those one mile and two mile high mountains represent a little more than 1 or 2 degrees respectively. I would think that would definitely be significant for one reflection. Other than ocean or lake midpoints, I would have to wonder about how much is reflected for a second hop. I remember figuring that in our Great Lakes areas, KFI was about 80 uV/m 10% skywave using the old skywave graphs for a single reflection.
If we take the arctangent of 1/50 and 2/50, those one mile and two mile high mountains represent a little more than 1 or 2 degrees respectively. I would think that would definitely be significant for one reflection. Other than ocean or lake midpoints, I would have to wonder about how much is reflected for a second hop. I remember figuring that in our Great Lakes areas, KFI was about 80 uV/m 10% skywave using the old skywave graphs for a single reflection.
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