HFU HF Underground
Loggings => European Pirates and Private Stations => Topic started by: Ray Lalleu on May 24, 2020, 1458 UTC
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Many signals are going up and down like mad camels !
Also with Doppler effects ? to a level quite unusual.
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Yes, very interesting...
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Many signals are going up and down like mad camels !
Also with Doppler effects ? to a level quite unusual.
I have only noticed that there has been sporadic e layer propagation at 27 Mhz and above, but also frequent evening E layer refraction in the evenings upto 7 Mhz at 100 km height, instead of the usual F layer at 250 km at those wavelengths.
Daytime propagation has been on the poor side, but evenings around sunset have been reasonable to good.
And that's the end of my propagation report. ;)
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Beginning of the Es season ?
Can that have effects on low HF bands? When combined with a strong normal E layer?
Also much noise on HF now (end of afternoon).
What news about the sun?
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Beginning of the Es season ?
Can that have effects on low HF bands? When combined with a strong normal E layer?
Also much noise on HF now (end of afternoon).
What news about the sun?
According to this morning's Radio Society of Great Britain RSGB propagation forecast, the solar activity this week is expected to remain low with the Solar Flux Index remaining at 70.
As far as I know the E-layer propagation blocks propagation to the F layer during strong iononisation, however, you might get signals partly from the E and F layer at the same time, via different path distances, but from the same station... this might cause the effects you mention. However, I speculate.
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Many signals are going up and down like mad camels !
I just started listening now, at 1720 UTC and I haven't noticed anything unusual, but, again, I'm late to arrive at the party. When you say "going up and down", is it anything like aurora flutter?
UPDATE: I am hearing Doppler-like effects now, 1737 UTC.
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Many signals are going up and down like mad camels !
I just started listening now, at 1720 UTC and I haven't noticed anything unusual, but, again, I'm late to arrive at the party. When you say "going up and down", is it anything like aurora flutter?
UPDATE: I am hearing Doppler-like effects now, 1737 UTC.
I have also not noticed this at my QTH either... but it could be that Ray is at exactly the right distance from, for example, Holland, to get a combination of E and F skip from the same station, simultaneously, this can make signals stronger or weaker, depending on phasing and refraction paths.... and considering we are talking about two completely different ionospheric layers, they could affect the signal in complex and sudden ways. It could be other factors though.
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Beginning of the Es season ?
Can that have effects on low HF bands? When combined with a strong normal E layer?
Also much noise on HF now (end of afternoon).
What news about the sun?
Current ionosonde readings over the south of the UK indicate HF signal refraction at 120 km, (e-layer), 240 km, (F1 layer) and 360 km (F2 layer), but there is still too much D layer absorption to really see how high the frequencies are for e-layer refraction to be honest. This should be clearer in about 2 hours time. As mentioned, these last few nights, E layer refraction was up to almost 7 Mhz
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I have also not noticed this at my QTH either... but it could be that Ray is at exactly the right distance from, for example, Holland, to get a combination of E and F skip from the same station, simultaneously, this can make signals stronger or weaker, depending on phasing and refraction paths.... and considering we are talking about two completely different ionospheric layers, they could affect the signal in complex and sudden ways. It could be other factors though.
Understood.
I am hearing Doppler-like effects and it is noticeable when listening to AM with a synchronous detector on several signals in the 48 meter band, so it's not just one station's VFO shifting; they are all doing this. With the use of the synchronous detector, you will hear a momentary distortion of the signal, as the effective carrier frequency shifts and as the PLL goes out of lock briefly, then comes back into lock after 0.5-1.5 seconds or so. I assume that SSB or CW would go through something similar.
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Beginning of the Es season ?
Can that have effects on low HF bands? When combined with a strong normal E layer?
Also much noise on HF now (end of afternoon).
What news about the sun?
Current E-Layer NVIS propagation upto 5.45 Mhz over S England... so non NVIS e skip possible at higher Freqs.
(https://www.ukssdc.ac.uk/ionosondes/pics/chilton/RL052_2020145181000.png)
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Long discussion, as I was away.
About up and down, it was about the levels of signals, going up and down much more than usually, say from quarter to quarter of an hour (each station behaving at its own pace).
About the Doppler effect, I am not sure, but the frequencies at 0.01 kHz seemed somewhat less stable, hard to tell from the usual drifting of many stations. But a 10 Hz (or more) Doppler shift would be quite unusual I think. But what can happen when there are ionized clouds/patches in the ionosphere ? Happily, a few stations seemed quite stable, so it's not a problem with my Rx (and I use the frequencies to 0.01 as help for identifying).