When does skywave actually kick in?

[vibe]

From Englewood FL, I've been trying to get KCRA Corpus Christi, a daytime only 50000 watt station and was successful at approximately 7:55 A.M. and 7:55 P.M. EST about 1 week ago. This was approximately 35 min after local sunrise and 50 min after local sunset. That got me to thinking (dangerous); is there an exact time when reception is considered skywave vs groundwave? Even though I got the Corpus station well after local sunrise, it was just about sunrise in Corpus. I still do not conside my catch as over the gulf daytime reception (to Texas).
Any opinions from those more learned or w/ more experience?

 

[1q2w3e]

From Englewood FL, I've been trying to get KCRA Corpus Christi, a daytime only 50000 watt station and was successful at approximately 7:55 A.M. and 7:55 P.M. EST about 1 week ago. This was approximately 35 min after local sunrise and 50 min after local sunset. That got me to thinking (dangerous); is there an exact time when reception is considered skywave vs groundwave? Even though I got the Corpus station well after local sunrise, it was just about sunrise in Corpus. I still do not conside my catch as over the gulf daytime reception (to Texas).
Any opinions from those more learned or w/ more experience?

Google "Greyline" and you will find a bunch of information. It varies but could be 45 minute before sunset and 45 (or more) after sunrise. Also depends on the season. Winter is more forgiving.

Once you find out about greyline, you can use it to your advantage. There are even programs that will allow you to see when it will happen

 

[pqgeorge]

For the most part, "greyline" skip starts occuring about 1 hour prior to sunset. In the morning, the skip begins to dissipate in the hour prior to sunrise. However, in the dead of winter (late November through late Febrary) you'll find that the skywave can occur about two hours before sunset and can stay active several hours after sunrise. I have actually gotten some substantial skywave reception in the middle of the day in the mid of winter listening to WWKB/1520 Buffalo, NY (during their now defunct oldies format). At 2:00 PM in the afternoon, it was coming in loud and clear in Manchester, NH where I was driving to work. That is over 400 miles away from Buffalo! The sun was still fairly high in the sky! I was totally floored on how well it came in the "Queen City".

Stick around for some great skip-land reception over the next few months. In fact, this is the time when the AM band begins to show some strength with longer nights and cold weather (my favorite time of the year!). Good luck and happy DX'ing!

 

[slim101]

I think you are talking about KCTA 1030 in Corpus Christi.
If so, KCTA uses a tall tower (more mV/m than a 1/4 wave tower). and it is also only about 9 miles from the gulf.
If you are on the west coast of Fla. it is very possible that you are hearing groundwave from KCTA, since 99% of the path is sea water.

 

[K4WRF]

Grey line is a good measure but the FCC uses a term called “critical hours” that is applied to certain “class-II” stations that operate on clear channels. By their definition, it is the time two hours after local sunrise and two hours before local sunset. Many of these class-II stations have to reduce power or go directional to protect the “Class A” from interference. So, skywave exist even after the sun comes up. More evident at the high end of the dial in the winter, there are days where some activity goes on all day. The condition is not considered on what was known as “class-III” or “class-IV” but has a definite impact and even more so now that they are allowed higher power levels up to 50kw on the “B” channels.

 

[jd]

I think you are talking about KCTA 1030 in Corpus Christi.
If so, KCTA uses a tall tower (more mV/m than a 1/4 wave tower). and it is also only about 9 miles from the gulf.

It's a very impressive tower, too, although the height was reduced slightly a few years ago too make it a little more efficient. It now stands at 246 feet overall height.

If you are on the west coast of Fla. it is very possible that you are hearing groundwave from KCTA, since 99% of the path is sea water.

I've lived in a number of places around Texas all my life and I'm pretty familiar with KCTA's coverage (even way back when their call letters were KWBU). They can be heard fairly well in the early morning and late afternoon around Dallas, about 350 miles from the tower, and they cover South Central Texas like a blanket throughout the day. When salt water is thrown into the equation, I don't doubt that vibe heard KCTA via groundwave. The station has a huge coverage area and comes in like a local along virtually the entire Gulf Coast of Texas.

Looking at the outer circles on their coverage map at www.radio-locator.com/cgi-bin/pat?call=KCTA&service=AM&status=L&hours=D it's obvious that their signal hugs the coast for a great distance to the east, not only over the Gulf Of Mexico but over land, too through the marshes of southern Lousiana and prossibly well beyond. Granted Radio-Locator's maps generally show exaggerated coverage, but in this case it's a pretty accurate depiction of where the signal goes. From the Lower Rio Grande Valley of Texas and throughout much of the Houston-Galveston area, press scan on your car radio and it will lock in on KCTA.

BTW, since KCTA lies west of the dominant station WBZ 1030, they're allowed to sign on at Boston sunrise time. That makes them a pretty easy early morning catch throughout much of the country.

 

[vibe]

Thanks for all your reponses so far, getting KCTA so close to local sunrise and local sunset in Englewood is great but I'm trying to get it between 9 and 5 so there will be no doubt that it was groundwave. There's sometimes 2 Spanish stations fighting it out on 1030 in the day. Speaking of WBZ it does make infrequent appearances at night here in Englewood but it's dominated by our friends to the south.

 

[rbrucecarter5]

In the early 90's, when KCTA played some CCM - it was solid going East until Baton Rouge in Lousiana. Amazing signal. Daytime Dallas is tough due to a local 1040.

 

[cheapman]

I've always found the most exciting time for picking up skywave is in the dead of winter during the late afternoon. Skywave has already started to kick in, but a lot of daytimers are still on the air and a lot of fulltimers are still on day pattern and power. Unfortunately there's only about an hour or so window before the dial quiets down. Kind of like that old saying about the best time for fishing: when the fish are biting!

 

[vibe]

The hour or so just after sunrise is interesting too-While in Fla, I'd been trying to get KLVI in Beaumont TX on 560 but the Miami AM station was too strong. While driving on I-75 just south of Ocala and about 30 min after local sunrise, I picked up and IDd the station (at 8AM). After breakfast all I could get on 560 was the Miami station albeit weakly.
The next morning on I-95 near Emporia VA and Petersburg VA the NYC blowtorches and WBZ were strong for about 45 min after local sunrise then nothing.

 

[gregndburg47]

Listening this am from South Mississippi, managed to pull in WFAN-660, as the top of the hour was near, heard several program r.eferences, such as being the flagship stn for "Imus", and some others.Also think I heard WCBS-880 at about the same time, sandwiched between WWL and WLS. WABC-770 was absent due to Laffayette, LA. New York is a rarity from here, I think that is the first time heard since after 9/11 when WCBS was heard right alongside of WWL.

 

[dxer720]

For the most part, "greyline" skip starts occuring about 1 hour prior to sunset. In the morning, the skip begins to dissipate in the hour prior to sunrise. However, in the dead of winter (late November through late Febrary) you'll find that the skywave can occur about two hours before sunset and can stay active several hours after sunrise. I have actually gotten some substantial skywave reception in the middle of the day in the mid of winter listening to WWKB/1520 Buffalo, NY (during their now defunct oldies format). At 2:00 PM in the afternoon, it was coming in loud and clear in Manchester, NH where I was driving to work. That is over 400 miles away from Buffalo! The sun was still fairly high in the sky! I was totally floored on how well it came in the "Queen City".

Stick around for some great skip-land reception over the next few months. In fact, this is the time when the AM band begins to show some strength with longer nights and cold weather (my favorite time of the year!). Good luck and happy DX'ing!

You're the first person that has actually answered my age-old question about nid-day DX. Here near Lake Geneva, WI, the big 50KWs make regular appearances from 500+ miles in the mid-day during the winter. THANK YOU so much.

 

[xjhb435]

At 3:15P today I was listening to 1160 WDJO Cincinnati, and WYLL Chicago briefly cut in a couple of times. That seems a little early for skywave and it never happened during the summer.

 

[AMonFM]

During the cooler months when the sun is lower in the sky, it's actually not uncommon to get daytime skip during good clear conditions. I heard the reason is having something to do with a lower amount of daytime charging of the ionosphere during 'solar minimum' periods. I really dont know for sure but I'll buy that. Seems everybody has a different theory.

Today while eating lunch, I was listening to both WTWP and WWKB in the car, the latter almost rock solid. Not bad for 250 miles. Also had CHWO mixing with WNYH Long Island. Ironically, the regional channels were pretty quiet at the time.

I think my personal record would be WLS in all day long (with some fades) on a cold late December day in Eastern NY state back in the 80's before 890 Boston came on the air. Signal remained strong enough to stay in stereo (remember AM Stereo?) the whole time.

 

[Tom Wells]

Today in St Louis, WRVA 1140 Richmond, Virginia was booming in like it was 100 miles away, at two hours before local sunset.
'Course the IBOC from KMOX 1120 was making a mess all over it.
This must be about 800 miles.

 

[xjhb435]

Today at about 1:30P while checking the extended band I pulled in the 1690 station in MD loud enough to positively ID it. In the summer, here in Columbus OH, nothing comes in on the x band but a low-powered 1630 from Franklin County's Solid Waste Authority (don't asky why; I don't know) and a low-powered 1640 from the airport.

 

[Grrrradio]

4:30 PM on Tuesday -- KRLD-Dallas was BOOMING in here in St. Paul, as was WTAM-Cleveland.

 

[semoochie]

On February 26, 1979(my mother's birthday)we had a total eclipse shortly after sunrise but late enough that skywave reception was gone. During the eclipse, skywave reception returned. This makes me think it's a darkness issue to some extent.

 

[cyberdad]

For whatever it might be worth....my "record" for cold winter days in Northern Illinois would be all day reception of WWL in the mid-70s, and then CHWO a few years back. Also on regular business trips to Eastern Canada in the '90s, WQEW was no particular problem day or night in wintertime. Then finally, in March 2001, listening to "Classic Gold" from London in Bonn, Germany all day was pretty easy. (97kw directional at 1548khz...about 400 miles distance, if memory serves)

 

[vibe]

With great skywave conditions occuring during the daytime and having listened to all the "blowtorches' from 500 mi and in, is anybody trying for the 5000 watt stations? For example 780 is an open frequency here in Central Mass. About 1 hr after sunset WBBM 780 Chi comes in well almost nightly but there is a 1 hr or so window just before and just after sunset where I hear a country music station calling themelves "Kicks or kix country. But I couldn't get a positive ID. A halfheatered (or slightly lower and heftier part of the body) attempt to ID the station on Radio Locator did not result in a positive result. I have gotton stations from as far away as Atlanta (NOT WSB) during this period that simply "disappear" about 45 min after sunset. To me it's fun to try and get the weaker ones at this time since they are much less predictable.