Thursday, June 7, 2012

E-Layer Skip Propagation

This form of propagation of VHF signals is most common in the summer months, but can happen at any time of the year. This is where signals bounce off this particular layer of the atmosphere, and land up to 1,500 miles away on a single hop. This form of propagation is called E-layer skip, or what's more commonly known to the Amateur Radio and TV/FM DX communities as "E-skip".

From my location near St. Louis, I most commonly get FM signals via this mode from Florida and New England. When the U.S. broadcast television in analog format, I most commonly got areas to the west (such as the Rocky Mountain states), as well as the East Coast. There are times when I can also hear Canadian and Mexican FM signals. With more Canadian stations converting to digital, opportunities to log new Canadian stations are getting fewer. So, I've been monitoring the lowest open FM frequency for skip conditions (in my area, it's 88.5 MHz, since local KDHX 88.1 is blocking 88.3 with their wasteful "HD" service). With Mexico taking it's time with digital TV, it has made it possible for me to log TV stations from outside the U.S., Canada and Mexico. Since U.S. full-power TV stations converted to digital in 2009, I've been able to add two new countries to my TV DX logbook via double-hop E-skip (Venezuela and Nicaragua). I've noted only a few openings reaching as high as VHF television channel 7; the last opening above 108 MHz I noted was in 2004, when I logged KHB38 Atlantic City, NJ on 162.400 MHz.

It takes just as much (if not more) patience to get a video capture on an analog E-skip signal than on a digital TV signal via the same mode of propagation or even tropo. Recently, I noted openings into Canada and Mexico on analog TV. This video capture was noted on May 29, 2012 from CKND2 (VHF Channel 2) from Minnedosa, Manitoba, Canada. The station it relays, CKND in Winnipeg, has already converted to digital. Note the small "Global Winnipeg" ID in the bottom right hand corner of the screen.

The next afternoon, I was able to get this video capture from XEFB-TV (VHF Channel 2) from Monterrey, Nuevo Leon, Mexico. What gives this one away is the abbreviation "Mty." That abbreviation stands for Monterrey. This is from an infomercial.

The same afternoon, I got this video capture from XEFE-TV (VHF Channel 2) from Nuevo Laredo, Tamaulipas, Mexico. This is across the river from Laredo, TX. The ID is clearly seen on this newscast.

With the conversion of U.S. television to digital, receiving the few VHF-low band DTV stations via E-skip is even more of a challenge. Very few can hold a signal for a long enough period of time to allow me to identify the station, forcing me to rely more often on the PSIP info on the digital channel. The only digital TV station received by E-layer skip that held its signal long enough to allow me to identify the station was WRGB (VHF Channel 6) Schenectady, NY. This was received in July 2009.

Receiving digital TV signals via E-skip is perhaps the most challenging part of TV DXing in the digital age. All of these video captures used a Hauppauge Win-TV-Go video card, which I installed in my computer in 2005 (since the Win-TV-D card for digital TV had been discontinued). A Zenith DTT-901 was used to receive the digital TV DX.

On the FM band, I have been recording more of my E-skip DX on a computer, especially since I added MP3 recording to my Magix Music Maker program. I have stored most of my FM DX on a Box account I added last year. I'm still using a cassette deck to record other FM DX. I don't own an "HD" receiver (and don't really care to own such a receiver, since I have Sirius-XM Satellite Radio), and being 20 miles from the nearest 100 kW FM stations, I can sometimes pull in DX over the digital sidebands of my locals.

My first experience with this type of propagation was in the summer of 1983. I had just added an Archer (Radio Shack) VU-110 to my setup. The antenna was pointed east and in the attic at my original QTH on Lamplight Lane; I pulled in WFSB (VHF Channel 3) Hartford, CT with their 11:00 p.m. newscast. What gave it away was the weather radar centered on the Hartford (CT)/Springfield (MA) area. Later, I was watching "The Tonight Show with Johnny Carson" on the same channel, and found a commercial mentioning Fayetteville; I thought I was pulling in KYTV in Springfield, MO (which is 91 miles, as the regional jet flies, from Fayetteville, AR). Imagine my surprise when the station IDed as WSTM Syracuse, NY! I would also get such diverse stations as KENW Portales, NM, WEDU Tampa, FL and KIDK Idaho Falls, ID on Channel 3 in the coming years. When I lived in Woodstock and Marietta, GA from 1988 to 1992, I also would get WFSB and WSTM on channel 3. In the Atlanta area, Channel 4 was an open channel. On E-skip, I would get such Channel 4 stations as KGBT-TV Harlingen, TX, KDUH Scottsbluff, NE and even WNBC-TV New York. The last E-skip opening I noted from Georgia, in June of 1992, was quite an experience. Bill Alisauskas in Douglasville tipped me that he was getting KGAN Channel 2 from Cedar Rapids, IA through local WSB-TV. Not only did I pull in KGAN that night, but also KFYR-TV on Channel 5 from Bismarck, ND through local WAGA. I did pull in KGAN one more time from my current QTH in 2008, through local KTVI.

On the FM side, I have had just as diverse of experience with E-skip. I started out with a pair of FM rabbit ears in 1983; the Archer (Radio Shack) Stereo Supreme. One E-skip opening into New England in 1985 gave me one memorable catch: WRDO-FM 92.3 Augusta, ME (with local WIL-FM off). I still have the QSL letter from that reception. I found the address only because the station had an AM affiliate on 1400 kHz. Today, that station is known as WMME (Moose). During the move from Woodstock to Marietta in the summer of 1991, I pulled in a station on 99.1 MHz with Colorado ads. On this frequency back then, I could count on either hearing Macon, GA or Huntsville, AL. The station turned out to be KUAD Windsor, CO. Even Chicago made it in via E-skip while I was in Georgia (WLIT 93.9...even with a local on 94.1). Since returning to Hazelwood in 1992 (it'll be 20 years on June 29), I've even been able to null out my locals to pull in E-skip. For example, I have been able to null out KDHX 88.1 to pull in WJIS Bradenton, FL (June 28, 1994) and KGNZ Abilene, TX (June 27, 1994). More recently, I was able to null out KPNT 105.7 to pull in CIGL Laval, PQ (July 29, 2009). One country I didn't log while I was in Georgia that I've logged in Missouri: Canada. The only other English-speaking country I logged from Georgia was Belize on 88.9 in 1991 (through semi-local WMBW Chattanooga, TN). My having taken one year of college level Spanish and one semester of college level French have helped me tremendously in identifying the Mexican and French Canadian stations.

I began operating on 6 Meters in 2006, after being a 2 meter operator exclusively since I was first licensed in 1992. So far, I've worked some 170 grid squares (2 degrees longitude by one degree latitude wide) on 6 Meters, mainly in single sideband. I've also worked several stations in AM mode, and one grid square each in FM and CW modes. I've worked the U.S., Canada, Mexico, Cuba, Antigua, Puerto Rico, the Turks and Caicos Islands, the Cayman Islands, the Bahamas and the Dominican Republic on 6 meters.

This is one of the most interesting forms of VHF signal propagation, in my honest opinion.

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