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Gw/nw-043

Well not expecting that.
Saw on reflector john was on 7118.
Low and behold dispute the crap conditions today on 40m and inter G very poor, not expecting to hear him for 2nd time on 2nd summit of day.

5/9 no problem, get in there, called in, loved the reply. “here’s the man with his own portable ionosphere”.
Certainly seemed that way. And made my day.

Yet afterwards dissipated into the noise gone. five minutes later,s he’s 5/9 again, shame he no hear M6RUG calling.

So goes to prove my point conditions seemed to be not happening, but that little sweet moment you have to be there to catch it especially when the odds are stacked against you. Don’t get that on the internet.

Hight light of the month I reckon

karl MK3FEH with own portable ionosphere :slight_smile:

I also listened for John MW0XOT - absolutely NOTHING heard here. Skip on 40 metres appears to be really short today!

73 Ed.

Skip on 40m is really non-existent today! Very patchy indeed. I monitored the JT-65 and PSK frequencies around lunch time and both were devoid of any signals. I did eventually manage a QSO on each mode without any difficulty, but I was rather strange to see totally clear waterfalls.

I worked John with ease on 40m at 11h48 utc. We were 1155 Km appart.
Cheers,

Guru

Same for me yesterday Gerald, I tried calling CQ on 40m from Billinge Hill G/SP-017. I cannot remember the last time I worked this band from a summit but it was utter garbage. My vertical antenna didn’t want to know. Just two QSO’s were completed…Esther GI0AZA and Ed DD5LP, both of them s2s.

73 Mike
2E0YYY

Gentlemen, may I introduce you all to the concept of Sporadic E propagation.

Bonus points available for anybody providing hard evidence suggesting such an event occurred around 1500Z!

Apologies for the lengthy post below but interestingly Andy, if you look at this series of ionograms from Chilton, the skip distance at 7 MHz did shorten somewhat around 14:40 - 14:50. (based on what happens with the critical frequency of the Extraordinary wave and the MUF versus distance)

73 Marc G0AZS





I used this one which shows the critical freq raise at the right time. My simplistic view is this was due to a sporadic E layer that came and went.

It shows a peak at the right time. It shows yesterday the foF2 was much lower. If XOT used a low dipole then he would have a large skywave signal. We can assume greater than 45degs and we can assume the foF2 the same in Wales as Chilton, so MUF = 6.2/sin takeoff or if 6.2/7.2 = 0.91, arcsin 0.91 = 66degs. any signal sent at less than 66degs would be reflected making a 200 mile path to Cornwall feasible.

Hmm yes but sporadic E would typically have shown as another lower layer on the ionogram(s) rather like the example below. I think in this instance it might just have been a “burp” in the ionosphere affecting the critical frequency.

Fascinating stuff… 73 Marc G0AZS

Earlier in the day Mike, I couldn’t find a free frequency on 40m and made my 16 contacts in 16 minutes on 40m from DM/BM-135 fighting two Russian speaking stations on the same frequency! A couple of hours later, when we worked, with me on DM/BM-226, the band was dead in comparison.

Propagation seemed somewhat “variable” yesterday to say the least!

73 Ed.

My image was just a plot of foF2 and not a full ionogram. You can see the sudden rise when John XOT became workable for closer in stations. I’m guessing the crow fly distance between John and Karl is quite a lot more than between John and Gerald. With the foF2 only around 6.2MHz short skip is going to be quite long.

It’s all fascinating stuff though.

Yes and don’t forget that for really short skip/NVIS, fxI (a close approximation of fxF2) vs. FoF2 might be more indicative of shorter range conditions… and was higher at 6.9MHz vs 6.2MHz for FoF2 at 14:40.

I worked Robert MW0VFC/P on GW/NW-038 at 1437z on 7.035 MHz from Scarborough. We gave each other 599 but then he was gone and I only heard stations from the continent work him.

73
Nick G4OOE

I have often wondered on SE on 40m band.
And yes the CT DID rise some what around the time i made the contact.
But his comment did tickle me.

But also so noted that noise again one like sea breaking on the shore along with his signal

When he on his first summit nothing heard CT poor and rest of inter G was well dire. But come afternoon its picked up a little and managed to reach John and the GB16YOTA in NZ-33 NE UK.

Looking at the ionosphere levels and what I know D layer reflects back signals in day light up to 10mhz and the higher the CT freq the shorter the distance between stations as in this case but the E layer is above the D layer and grey line not quite reaching me here till about 1530hrs as noticed of late run the chart for the grey line and Cornwall is last to enter in the UK.

End of day, it happens and when it does its magic and defies the odds stacked against you.

Even in this day and age the ionosphere still can be bit of a mystery at times.

karl

What is CT?

Other way Karl, D layer absorbs not reflects and absorbs more the lower the frequency. D layer absorption is what makes 160/80m etc poor during the day time.

Think it should be CF = critical frequency…

Doh sorry folks CF, thanks for that andy

karl