Single Station DX

[NN2E]

Getting KOTV-DT 55 (6) Tulsa, Ok. (410 mi) this morning and nothing else. No other Tulsa stations. No Missouri stations. No Arkansas stations. Just KOTV-DT all by itself. I know Antennanut has see this happen and it's not the first time I've seen it. Has anyone else experienced one of these "single station" band openings?
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

Update 11 a.m. - It took about 10 hours but things have finally opened up. Here's that late morning tropo, again...
KTVE 27 (10) El Dorado, Ar. 340 mi.
KLRT 30 (16) Little Rock, Ar. 270 mi.
KFSM 18 (5) Ft. Smith, Ar. 345 mi.
KYTV 44 (3) Springfield, Mo. 255 mi.
And a new one...#186 KASN 39 (38) Pine Bluff, Ar. 270 mi.

[NN2E]

For the past 24 hours I've been seeing KLRT DT 30 (16) but nothing else from Little Rock.
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

[Robert Grant]

My longest tropo (in August, 2007 IIRC) was almost a single station opening. The longest DX (KATV-7, Little Rock, 690 miles was joined only by KARK-4 (also Little Rock, 684 miles) and, very oddly, KCRG-9 (Cedar Rapids, IA, forget the distance, but it's about 350 miles - in a totally different direction). In this opening, NOTHING but these stations showed any enhancement, NOT A TRACE of any tropo on UHF.

WBXX-20 and WDBJ-7 have also been seen in single-station ducts. This effect occurs when the tropo is in a tightly defined duct, rather than a reflection layer.

WNYB-26 (226 miles) often presents as a single-station opening, no mystery here, it is uniquely positioned for a clear path over Lake Erie.

[NN2E]

Hi Rob,
One thing these transmitters seem to have in common is a pretty good HAAT.
Here are a few I've seen by themselves.
I've converted HAAT to feet....
KOTV-DT 1618
KLRT-DT 1481
KTAL-DT 1468
And the ones you mentioned...
KATV 1950
KARK 1660
KCRG 2003
WBXX 2435
WDBJ 2013
WNYB 1528
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

[KA9UVY]

Ed, Something also related to height above ground but not so much single station DX.
I have seen band openings where the low power stations are much stronger than the full power stations. That could also be explained by height above ground as many of them are under 500 feet.
I believe that ducting not only changes in frequency but also definatley can move up or down in relationship to the ground.

Just my 2 cents

73, Bob
KA9UVY

[Robert Grant]

First: Thanks!, Ed. And it does make sense - sometimes a duct can form at only the higher altitudes (the Hawai'i - Calfornia duct is famous for this).
In Michigan, one can only benefit from such a duct if one happens to be just outside the duct zone, that is, the place were the RF can finally "leak out of the duct" and get back to the ground level.

And, yes, there are ducts that favor low altitudes - even ground-based ducts. On the rare occassions that I've been able to see tiny WVIZ-DT 26
(1kW @ 30 m), the full-power Cleveland stations are often not very strong.

[NN2E]

Bob & Rob,
My first experience with stratified layers of air happened many years ago. I used to fly hot air balloons and would often notice distinctly different layers of air as the balloon gained altitude. Sometimes, on warm, humid, Summer evenings I would ascend, say 1000 feet or so, and then enter a cooler, dryer, layer of air with a different wind direction. I'd actually feel a cool breeze as I entered the new layer. This always got my attention because a balloon travels with the wind and you normally don't feel any wind at all. One of these cooler layers might last for a few hundred feet and then as I gained more altitude I would get back into another layer of warm humid air. It's my understanding that ducting can take place in one of these stratified layers.
Now, looking back on it, I wish I'd taken a battery powered TV up with me.

I've also noticed the opposite of the low power, low tower, enhancement... where a local signal will fade or disappear for a short time. Occaisionally WKPD at 20 miles will fade out. This usually happens just after sunset on calm nights.
I've even seen WKMU's signal take a dive and my tower can see their tower!
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds