eskipper411 said:
If a station is fading in and out on Analog, is it Es?
as gr8oldies says, not necessarily.
A few characteristics of Es:
- Distance is between 700 and 1,200 miles. (distances as short as 400 miles have happened but less than 700 is quite rare; likewise, distances of as much as 1,500 miles happen but are rare. "multiple-hop" openings of up to 4,000 miles have happened but the vast majority of us will never observe one.)
- ALWAYS starts at lower frequencies and moves up. If there's nothing doing on CB or the 10-meter ham band, but FM is wide open, it's probably NOT Es. Used to be you could use TV as a predictor of Es -- if you had TV DX on channel 2, there was a fair chance something would hit FM in an hour or so. It's a lot harder (but not impossible) to receive digital stations via Es. That said, the analog TV stations are still on the air in Canada, Mexico, and Cuba and can serve as notice of FM Es openings to those countries.
- Yes, there is a *minimum* distance. A station 300 miles away is NOT Es.
- Most likely in mid to late morning (~10-11am) and mid to late afternoon. (3-5pm) Can happen at other times though.
- Most likely in late spring to early summer (May, June, July).
- DEEP and RAPID fading. Signal may be perfect, then over a period of a second or two fade out almost completely (often to be replaced by another DX station), then fade right back in at full force.
A few characteristics of tropo (the other major DX mode):
- No minimum distance, but a considerably shorter maximum. Stations more than 500 miles away are rare, most DXers will never hear anything more than 1000 miles away via tropo. Stations as close as 30 miles may be enhanced.
- Does NOT always start at lower frequencies -- indeed, it often starts at higher frequencies. If you're getting distant digital TV signals on UHF frequencies, FM DX from the same places is probably tropo. UHF TV DX **is** tropo. The highest frequency at which Es has been reported is 225MHz - UHF Es is unheardof.
- Depending on your location, can happen any time of year. (in the North, tropo is VERY rare in winter. In the South, wintertime tropo is quite common. In both regions it happens all summer long, even in late summer after Es has begun to fade.)
- Better at night and, especially, just before and just after sunrise.