Greyline Index Page:-. Recordings of Signal Strength to Observe any Dusk/Dawn Greyline Enhancements. These will also give a record of the propagation on the paths during the recording period. Please excuse any missing pages and images, I only have limited space so have to delete older pages, sometimes leaving something behind. Hopefully I can find it all if anyone is interested.
SUMMARY:- I have been observing various low frequency paths for four years now. The RSGB study intrigued me and these enhancements are mentioned by DXers, some who seem to claim to be able to predict them. I have not found any detailed studies, most references give a fairly vague summary.
I have not examined many paths, suitable continuous, identifiable transmissions are rare. Two I have looked at in detail are the paths between here and Africa and Australia . While these paths show enhancements they are by no means consistent or regular. Many times there are no peaks, when they do occur the time of peaks varies and often the strength of peaks is lower than signals at other times during the night. It seems to me that the longer paths with a relatively short-lived darkness path are more likely to show significant dusk/dawn enhancements. I think this may be because although many signals do show an increase in strength around dusk and dawn "normal" overnight propagation is likely to produce stronger signals. Some paths I have looked at, for example USA to UK have not shown much evidence of enhancements, I am looking at these again August 2008.
Some seem to suggest that when both stations are mutually in sunrise or sunset signals are especially strong. Opportunities to look at this situation are rare, it happens only for short periods for each year except for stations near the antipodes. Z:LXA is close to that with me but the problem then is that there is no non-greyline propagation to compare. I do not feel that signals from there peak particularly strongly, even on that path the timing of actual peaks are variable. The path to ZL is open regularly on 80 metres, maybe because many variations in the path are possible. The RSGB conducted tests with VP8FI, the African stations are mutual at times but I have yet to see any exceptional propagation effects.
The effect has been reported on higher frequencies, but I am not aware of any suitable transmissions that are on for long periods. The amateur beacons are an exception. The NCDXF beacons are continuous although they only transmit for 10 seconds every 3 minutes and can be subject to interference. VE3NEA has a program to monitor them but it is shareware. Using this during the trial period I have seen no greyline peaks. The beacon DK0WCY on 10.144MHz could be observed, most other regular ones are on 10 metres or above although some personal QRP amateur beacons are setup..
I mainly use broadcast stations, a few in the tropical bands are identifiable and on all night. They could be observed and recorded from most places around the world. I would be interested if anyone else could join in. Can anyone demonstrate reliable Greyline? I will do my best to help someone get started. I have tried to describe my techniques on other pages, see my index below.
Now starting some recordings of North American stations. 5070/5025/3330KHz. August 2008. 5070/5025/3330KHz. September 2008.
Recordings of 3396KHz Gweru Zimbabwe to end of June 2007: 4828KHz. July 2007: 4828/3396KHz. August 2007. Including a simultaneous look at RSG Meyerton 3320KHz. 4828/3396/3320KHz. September 2007. 4828/3396/3320KHz. October 2007: 4828/3396/3320KHz. November 2007: 4828/3396/3320KHz. December 2007: 4828/3396/3320KHz. January 2008. 4828/3396/3320KHz. February 2008. 4828/3396/3320KHz. March 2008. 4828/3396/3320KHz. April 2008. 4828/3396/3320KHz. May 2008. 4828/3396/3320KHz. June 2008. . 4828/3396/3320KHz. July 2008. 4828/3396/3320KHz. August 2008. 4828/3396/3320KHz. September 2008.
ZLXA 3935KHz. Identity was unlikely to be positively confirmed. But thanks to it's distinctive carrier and ZL1BPU....! August/September 2006 Recordings of ZLXA 3935KHz. July 2007 Recordings of ZLXA 3935KHz. August 2007 Recordings of ZLXA 3935KHz. September 2007 Almost daily recordings from September 2006 to September 2007 - contact me.
Recordings from 5019.874KHz Reported to be Solomon Islands Information and some recent recordings. Signal Improving September/October 2007 Now a year's record of reception available.
Notes on using SpecLab to observe and make recordings
Some Examples of Dusk/Dawn Enhancements on Various Stations. Some Techniques used to identify stations.
Recordings from VP8FI on Various Frequencies These are attempts to record "true greyline". November-December 2004
Notes About Some Stations Observed.
Below, a list of most of the many recordings I have made. My ISP only gives me 10MB of space here. Please email if interested.
3 Sept 2006 ZL1BPU on 3518.0000KHz based on Rubidium standard.
Recordings of ZLXA 3935KHz. October 2006 November 2006 December 2006 January 2007 and carrying on through June
2007
Recordings from 5019.874KHz Reported to be Solomon Islands but unlikely to be absolutely positively confirmed. Shows some peaks around Solomon Is. dawn.
Recordings from 5019.874KHz Reported to be Solomon Islands November 2006 December 2006 January 2007 and carrying through June 2007.
12 Recordings 10-15 May 2006 of various stations
Recordings. 15 May 2006 on - Mainly Christian Voice Lusaka 4965KHz with some others mixed in.
Christian Voice, VOA 4930KHz etc. July 2006 August 2006 Including mutual greyline period.
Recordings of Radio Sonder Grense, Meyerton. 3320KHz. May/ June 2006, July 2006, August 2006. Including mutual greyline period. September 2006.
Recordings restarted August 2007 as a comparison for the Zimbabwe stations.
Recordings showing the few recordings from Alice Springs 2310KHz when signal strength was higher than normal. Jan-April 2005
Recordings on 2310KHz from Alice Springs Australia . Jan-April 2005
Australia Continued Recordings from Northern Territory stations. 120 metre band.
Mainly Alice 2310KHz. October 2005. November 2005 December 2005 January
2006 February 2006. March 2006. April 2006
Recordings from Perth Western Australia on 1620KHz (I made it 1619.965) October/November/December 2005
Recordings from Sydney? New south Wales Australia on 1701KHz (I made it 1701.076) November/December 2005
Recordings from Sydney? & some others Australia on 1701/1620KHz January 2006 1701/1620KHz February 2006
Some more recordings of AM, Medium Wave stations. Oct 2005
More miscellaneous recordings of Medium Wave stations. February 2006
A Study of WDHP 1620KHz USA Virgin Islands.
Recordings on 3210KHz from Nashville USA Dec 2004 onwards Oct 2005. On 3215KHz
now some from July 2008.
Recordings on 5070KHz from Nashville USA. Oct 2005 Restarting July 2008.
A Comparison of reception from Alice Springs 2310KHz and Perth 1620KHz on 31 October 2005. Shows SpecLab "waterfall" (sideways) and Excel chart derived from the saved data. A similar reception pattern seen.
Click link to email If you see no link or it does not work Click HERE Please include "Greyline" in the Subject Line. Make the subject VERY relevant - with the amount of spam I get an email from an unknown source can easily be discarded!
Grayline - alternative spelling.