Re: LF: TA CW?

["Alan Melia" <alan.melia@btinternet.com>]



Hi John yes I agree totally with your assessments I had forgotten Peter was active at the same time...knowing the date now I will search back through the archive and look at the Dst as this was before my discovery of that connection.

 

This reflector will not carry the images (bmp) from Colorado plots, which show that the Eq. Ring Current was not too highly topped up. The Dst was hovering about -30 to -40 nT ....a bit below best conditions. The 6th is characterised by a suddent fairly rapid rise in Dst to 0nT. This usually is the precursor to a downward swing to maybe -60nT However this depends upon the direction of the Cme magnetic field. Without researching further I suspect that the field did not reconnect because the Dst droped back to around only -40nT.  I suspect that burst from Laurie was a happy coincidence of the positive swing of Dst and the phase coincidence of the multi-hop signals......that rare event that all amateirs pray for, a path opening at the right time. I am not sure the positive swing is significant in radio terms, because I cant see it sweeping the D-layer clear of absorption, so I am guessing the in-phase "sweet spot" is the real reason.

 

Was that the first E-W reception contact of had Laurie made it Caanada earlier John??

Alan

G3NYK

----- Original Message -----

From: w1tag@charter.net

To: rsgb_lf_group@blacksheep.org

Sent: Wednesday, September 25, 2013 4:04 PM

Subject: Re: LF: TA CW?

 Further to Alan's posts, some thoughts on the earlier 72 kHz TA reception from December, 2002.

TA signals from G3AQC and G3LDO (among others) on 2200 meters had been regularly copied in the eastern U.S. This was all done at QRSS60-120 data rates. The end of the 72 kHz NOV's in the UK was approaching, and Laurie and Peter began transmitting regularly at 72.4 KHz, with Laurie using something close to DFCW240. Nothing was reported from over here until the evening of 6 December 2002, when I put the receiver on after dinner, and saw a strong signal where none had been in the previous week. I sent out emails, and over the course of the evening, the only U.S. copy of Laurie was from Jay, W1VD and myself. Watchers further south and west reported nothing. We believe that Laurie signed off around 0130...in any case, the copy ceased.

Looking back at solar weather records, nothing unusual seems to have been going on. Activity was higher than present, no surprise, but there had just been a regular succession of fairly minor events. This suggests that Alan's famous "leaky reservoir" was fairly full, but that LF conditions had not been depressed by a recent CME.

Speculation at the time was that we caught a period where the signal "hop" landed in this part of the U.S. I believe this would have been a 3-hop path (Alan will correct me), but this might have been a time where the 2nd and 3rd hops happened to end in phase over here. Jay and I are 100 km apart, pretty close for this sort of thing, but the unsuccessful listeners were considerably farther away.

This record may fall with the use of higher power, but Alan is definitely correct about the effectiveness of Laurie's unusual antenna.

John, W1TAG