Here's an odd one...

Tim58hsv

DTVUSA Member
#1
For over a year my converter box has been picking up a weak signal (no picture or sound) from a channel 19 from who knows where. I've searched high and low for any tv station within a 100 miles from here that was using the rf 19 frequency but came up empty handed. Well a few mornings ago Mr. Skippy payed a visit and the station finally came in and it's from Louisville, Ky., 135 miles away!

Why on earth would I be receiving an almost constant weak signal from a tv station so far away? I get plenty of weak tv signals from Columbus and just over the river in northern Kentucky but those signals are only around 60 miles away. Any idea why that one tries to come in almost 24/7?

Here's a screen cap from the station.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#2
Tim,

That's fantastic ++ ! :dance: How about trying a TVFOOL report based on 100 ft or 150 ft elevation to see if that station appears on the roster? (disclaimer: I have no clue if TVFOOL can work with that height) That's real DX ... what are you using for an antenna and currently, how high up? I wonder what would happen if you had a dedicated (long) channel 19 Yagi pointed toward them?

Jim
 

Piggie

Super Moderator
#3
Tim, I see this is Florida on the lower UHF channels. I am not sure which ones to call the "lower" ones, but probably 14 through somewhere around 23 to 24. They really have a lot more range compared to the ones say in the 30's. There are several on the lower UHF that are almost always there "wiggling" my meter but well below any chance of decoding without tropo.

And over the years on TV, FM, Ham radio V/U bands, I have just seen paths that were "hot". There is no doubt explanations if deeply investigated. But two stations in the same town, roughly same distance and one is a lot stronger.
 

Don_M

DTVUSA Member
#5
Short-run DX happens now and again under favorable conditions. I get a late-night lock two or three times a month on CBS affiliate KGWN 5.1 (RF 30) despite a distance of 102 miles, diffraction of two edges, an attic-mounted antenna, and being in a region where there are two chances for tropo ducting: slim and none. The signal-level meter shows that KGWN Is regularly just below the lock point. Its signal was totally blanked by KDVR-TV on 31, the 5-megawatt Fox affiliate in Denver, until the analog cut-off. Once KVDR-TV was gone, KGWN-DT started showing up.
 

Piggie

Super Moderator
#6
I think, not to discount anyone's post, but Tim (I think, clarify if needed Tim) why some channels out of many other might propagate farther (even if they don't decode) than others without tropo or other enhancements. Like I said I see this in Florida on several of the Orlando and Tamps UHF's in the low end of the band. And then due to many factors, even if distance are the same, some come through and some not under "normal" conditions. I see it from Orlando all the time on the lower channels but they don't decode on my system without tropo. A good example, now days past was RF 18 out of Orlando in the NTSC days. That station, was always there once the sun went down, with enough signal to get a color lock, though normally with noise. It didn't take tropo to see it. But if I tried any other NTSC from Orlando on UHF, they would not even lock up sync bars. Why 18 got there so good, with all the transmitters in the Bithlo/Christmas antenna farm within 3 miles or so of each other I have no idea. But it does follow on me stating again that the lower UHFs really do punch through farther, all other factors equal, than the high UHFs.
 

Tim58hsv

DTVUSA Member
#7
Tim,

That's fantastic ++ ! :dance: How about trying a TVFOOL report based on 100 ft or 150 ft elevation to see if that station appears on the roster? (disclaimer: I have no clue if TVFOOL can work with that height) That's real DX ... what are you using for an antenna and currently, how high up? I wonder what would happen if you had a dedicated (long) channel 19 Yagi pointed toward them?

Jim
The antennas I use are of various 4-bay designs such as the U-4000 and/or the G-1483 mounted at around 25' high so nothing special there. I did do the TVfool report at 125' (my zip is 45432) and it still doesn't show WBKI as a possibility. Compared to the results I get there with antenna at 25' it does appear TVfool works at 125' too.
 

Tim58hsv

DTVUSA Member
#8
Short-run DX happens now and again under favorable conditions. I get a late-night lock two or three times a month on CBS affiliate KGWN 5.1 (RF 30) despite a distance of 102 miles, diffraction of two edges, an attic-mounted antenna, and being in a region where there are two chances for tropo ducting: slim and none. The signal-level meter shows that KGWN Is regularly just below the lock point. Its signal was totally blanked by KDVR-TV on 31, the 5-megawatt Fox affiliate in Denver, until the analog cut-off. Once KVDR-TV was gone, KGWN-DT started showing up.

I think, not to discount anyone's post, but Tim (I think, clarify if needed Tim) why some channels out of many other might propagate farther (even if they don't decode) than others without tropo or other enhancements. Like I said I see this in Florida on several of the Orlando and Tamps UHF's in the low end of the band. And then due to many factors, even if distance are the same, some come through and some not under "normal" conditions. I see it from Orlando all the time on the lower channels but they don't decode on my system without tropo. A good example, now days past was RF 18 out of Orlando in the NTSC days. That station, was always there once the sun went down, with enough signal to get a color lock, though normally with noise. It didn't take tropo to see it. But if I tried any other NTSC from Orlando on UHF, they would not even lock up sync bars. Why 18 got there so good, with all the transmitters in the Bithlo/Christmas antenna farm within 3 miles or so of each other I have no idea. But it does follow on me stating again that the lower UHFs really do punch through farther, all other factors equal, than the high UHFs.
It's weird just like the cases you guys pointed out. There's plenty of tv stations within 130 some miles from here but only WBKI almost constantly wiggles (sorta' quoting Piggie :)) the meter.
 

BCF68

DTVUSA Member
#9
Makes sense lower UHF would come in better than higher UHF. Hi-VHF takes less power to cover the same area as UHF and low-VHF take less power than Hi-VHF. So logically if you have 2 stations on at say Ch 51 and the other on Ch 14 both have towers in the same area and transmitters are the same height and both are at the max 1000 kW then the Ch 14 would cover more area. The difference between the end of Ch 14 and the begining of Ch 51 is 216 MHz. The difference between end of Ch 13( hi-VHF ) and the begining of Ch 14( UHF ) is 254 MHz. It would seem the FCC would have used a sliding scale for UHF for power. I'm not sure of the numbers, but it would seem if a new station wanted to start up they would need at least twice the power at 51 to cover the same area at they would if they used Ch14.
 

Trip

Moderator, , , Webmaster of: Rabbit Ears
Staff member
#10
Are you certain the signal you're seeing all the time is WBKI? 135 miles is rather far, in my opinion. It would make more sense to me, at least, for your mystery 19 to be a different station (WDNI-CD in Indianapolis?) and tropo just brought in WBKI that morning.

- Trip
 

FOX TV

Contributor
#11
Strange signal paths !!

For over a year my converter box has been picking up a weak signal (no picture or sound) from a channel 19 from who knows where. I've searched high and low for any tv station within a 100 miles from here that was using the rf 19 frequency but came up empty handed. Well a few mornings ago Mr. Skippy payed a visit and the station finally came in and it's from Louisville, Ky., 135 miles away!

Why on earth would I be receiving an almost constant weak signal from a tv station so far away? I get plenty of weak tv signals from Columbus and just over the river in northern Kentucky but those signals are only around 60 miles away. Any idea why that one tries to come in almost 24/7?

Here's a screen cap from the station.
We have a similar situation with a viewer at 117 miles out in a very mountainous area of West Va. He reports that he has solid lock from our CW transmitter on a constant basis. He could even see our low power signal from that same site, even before we replaced the transmitter and antenna, and considering the power levels of the old low power transmitter and antenna, that seemed impossible at the time, but he was watching it when he called the station and described the programming that was on at the time.

There is also an adjacent VHF transmitter on channel 13 located beside ours that he can also receive, even though he cannot receive any other of the transmitters from this market from the top of a 4,000 mountain, which is almost twice the elevation of the site he can receive. The VHF reception is not real surprising, but he could also receive them before they reverted back to VHF.

Looking at terrain mapping sheds no light on the issue, as there are many obstacles that should make this path unusable for this viewer. There must be just the right combination of mountains, reflective rock faces, and other physical phenomenon that make this possible, when all other known factors indicate that this should not be possible at all. There must be some type of reflective path that allows this to be possible that defies all logic of what we think we know about RF signal propagation.

Very Strange indeed. Is it just coincidence that these are both CW stations, or does the CW programming contains some type of propagation modifying magic ?...Just kidding !!
 
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Tim58hsv

DTVUSA Member
#12
Are you certain the signal you're seeing all the time is WBKI? 135 miles is rather far, in my opinion. It would make more sense to me, at least, for your mystery 19 to be a different station (WDNI-CD in Indianapolis?) and tropo just brought in WBKI that morning.

- Trip
That's a possibility of course but the main reason I believe it is WBKI trying to come in here is because that same morning the only other channel that was coming in via skip was WCVN out of Covington, Ky which is another station my converter box gets an almost constant signal from but no sound or picture and both station are to the south of here. Indianapolis itself is around 110 miles away and the station there is only putting out 15kw of power so it's doubtful it's the mystery channel 19 imo.
 
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Tim58hsv

DTVUSA Member
#13
Bumping this one up to say a few month back that mystery channel 19 came in again via skip and I thought, yup, that's WBKI from Louisville but as it turned out it wasn't. This time it was WVAH from out of Charleston, WV. That ones 170 miles away and about only half the power of WBKI but it got me wondering if maybe these two signals, as weak as they must be this far from their transmitters could be combining enough around here to cause the converter box to show an almost constant signal on real channel 19? Seems like a possible explanation?
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#14
Hey Tim, LTNS.

170 miles away? WOW+++ :thumb:

I'm not an expert regarding this, but I highly doubt digital signals can 'combine' to carry each other additional distances in the digital world. I think you received genuine skip or ducting. If I'm wrong, someone tell me, after all, we are all here to learn.

This isn't Amplitude Modulated Broadcast Band, Shortwave or CB Radio that all have a common to them, an empty carrier wave waiting for modulation to be added to it. When listening to shortwave radio, many times I heard distant stations 'piggyback' their signal on top of megawatt stations 'loading-up' and honestly (since the Statute of limitations has run out ...) when I was a teenager I 'piggybacked' my Ham transmitter on top of some of the same megawatt Shortwave Stations to see what would happen. Who knows how far "I traveled" ...

Jim
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#16
I wonder if the neighbors will be upset when I put up a 500 foot tower?

(Im gonna cgo heck my bank now, and see if they will give me a loan for a tower.)
 

Tim58hsv

DTVUSA Member
#17
Hey Tim, LTNS.

170 miles away? WOW+++ :thumb:

I'm not an expert regarding this, but I highly doubt digital signals can 'combine' to carry each other additional distances in the digital world. I think you received genuine skip or ducting. If I'm wrong, someone tell me, after all, we are all here to learn.
Jim
I don't think they're carrying each other but that they are intersecting around these parts and their combined power (both WBKI & WVAH being on the same exact frequency) is what's causing the converter box to almost always show a signal reading on channel 19. I can't see either station doing so by itself but maybe it is due to what Piggie called a "hot path."
 
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