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[AA9G]

Hello all,
I am wondering for roughly how long does grey line prop last and about how wide is the path?

[KG6YV]

If you 'google"  dxmaps and bring up the realtime world view with the grayline box checked you can see actual traffic on each band and easily see for yourself.  20 and 17 meters show grayline contacts very well this time of year.  In the winter 80/40 will do the same.

[W7AIT]

I work a lot of grey line DX on upper bands.  My actual observations:  Actually distance measurements seem to roughly indicate about 900 - 1200 miles is the furthest the DX station can be from the line.  Further than that the DX seems to intermittently fade away, or go totally away while QSO in progress (the distance increases past 1200 miles with QSO in progress), or I can't hear them at all.

This is looking at Google Earth globe view with terminator view turned on. 

Distance measurement is made with the Google Earth ruler.  Ruler placed perpendicular to terminator, starting end at the sharpest demarcation of dark / light, and then the other end directly over the DX stations location, on the sunlight side.

I've repeated the reverse on the other side, but often find distance doesn't matter if the DX station is in total darkness working toward me into sun light.

Keep in mind the band used and the conditions affect the accuracy of the measurement.

[KE4JOY]

20 meter grey line, at least here, has been kick butt the last couple of weeks. Starts right around 8:00 pm est and lasts to about 9:30 pm est.

It may actually go later and start earlier but those have been my times of 'best performance'.

I have worked the middle east, Ireland, Belgum, the Caribbean amongst others easily with 100 watts and a dipole.

The rest of the day has been quite poor. I noticed last night, just before grey line activity the band all but completely conked out with just a few strongish signals then all of a sudden BAM south America and others started rolling in.

20 meters is just plain odd these days.

Nothing scientific about it just personal observations.

[N3QE]

I think there's several different things going on that may be called "grey line".

On 160 at our sundown there is often an enhancement in signals to EU. Same at their sunrise. Not sure this is "real greyline".

On 80 and 40, I get super duper reliable paths to VK and ZL before and at my sunrise. Often on 30M too, and sometimes on 20M. This is, I'm sure, "real greyline". Less reliably I also work JA and sometimes even have heard BY's at this time, but it is far less reliable than VK/ZL path.

On especially 20 and 15 in the summer it is often useful for one or both ends to be in darkness. I think this had to do with solar storms/CME's that would severely disrupt communications in daylight conditions. But it seems to often be true even when I don't see any storms on spaceweather.com.

[GW3OQK]

I am interested in this too.

The other evening at 2035 BST I was in QSO S9+30 each way, on 3.5 MHz with another GW 40 miles away. The Grey Line started passing, some rapid QSB started, we faded out and lost comms within 10 minutes. So, it can kill local comms rapidly.

On the other hand I recall hearing ZL on 160m in the grey line period, but it only lasted 5 minutes.

I can confirm that approaching and during my GW sunrise and NA sunset conditions can be enhanced for up to an hour. I worked 40 North Americans that way one morning, on 160m, including Arizona and Mexico.

Andrew
GW3OQK



 

[N4JTE]

Just want to make sure some are not confusing getting dark at your house with greyline propagation. Both stations being in the dark is totally differant. Most greyline prop is very shortlived and usually on a North South path while the other area is approaching sunrise.
Not easy to time right but when it does it's a trip!
Bob

[W6QW]

Well, I worked OH6NUW this morning (August 26th) on 40 meter long path (CA to Finland) at 1430 UTC (S5 signal strengths).  He was about 2 hours until his sunset and I was 1 hour past sunrise!  About 30 minutes later, I worked 9K2GS on 40M long path (S9 signals).  At that point I was 1.5 hours after sunrise and he was about 45 minutes until sunset.

So, here is an example that demonstrates that the Grey line can be quite wide and well outside the normally assumed active time of the year.