Backscatter on 40 MHz - 19th May 2021

Wednesday 19th May 2021: The day started with a comment by Joe, EI3IX on a Facebook post that he wasn't hearing the new EI1CAH 40 MHz beacon even though he is only 64kms from it. That set me off checking why that was the case and I ended going down a rabbit hole that saw me on the 8-metre band for most of the day!

Both the EI1CAH (40.016 MHz) and the EI1KNH (40.013 MHz) beacons are about 200kms from my location with plenty of hills and mountains in the way. I listened early on the morning of the 19th and I couldn't hear either beacon although I did get a meteor burst from EI1CAH so I knew that it was still operational.

A few hours later, I tried listening again and I found I could now hear EI1CAH all of the time! What had changed? As the signal was buried in the noise with a Signal to Noise ratio of -26dB, my initial thought was that it might be tropo? However, I couldn't rule out that it may have been to Sporadic-E backscatter either.

It was only later when I saw the signal improve to -6dB over the space of a few minutes then I knew it was Sporadic-E related. While there are no doubt slight tropo enhancements at 40 MHz, large changes like this are almost certainly due to Sp-E.

Later when I checked the EI1KNH beacon near Dublin, I could that as well. At that stage, I was 100% sure it was backscatter. Lloyd, EI7HBB reports hearing both beacons by backscatter as well.

Backscatter Sporadic-E: What is it? Refer to the diagram below...

The signal from the EI1CAH beacon (TX) is being propagated forward by an intense Sporadic-E region about 100-110kms above the Earth. The signal is then being reflected off something maybe 500kms or so away... maybe a range or mountains? The signal then returns by pretty much the same path and I hear it at my location (RX).

I've heard backscatter via Sporadic-E several times before on 10m and 6m. Back in the 'old days' when everyone was on either on SSB or CW, I remember beaming South to work stations in the UK on 50 MHz.

The signals seem to have a certain characteristic in that they are pretty constant but just at a very low level. This is what I was hearing... EI1CAH was a weak but constant signal for most of the time with the occasional jump.

The truth is that backscatter is probably there all of the time during Sporadic-E openings but we're not aware of it as the signals are so weak. When there is an intense Sporadic-E with the skip distances much shorter (e.g. <700kms), signals get a LOT stronger.

Imagine a signal being reflected off a distant mountain range which is 1500kms away which is a pretty normal skip distance for Sporadic-E at 40 MHz. Now imagine the range reduces to 500kms under intense Sporadic-E like there was on the 19th of May. Obeying the inverse square law, the transmitted signal at the mountain range would appear 9.5dB stronger. But crucially, this also applies to the reflected path resulting in an additional 9.5dB enhancement. This adds up to a 19dB improvement overall in signal which is a really big jump. 

Back in the 'old days' with SSB/CW, backscatter via Sporadic-E was something that was observed on an occasional basis. Now that we have digital modes like FT8 and PI4, we are 'hearing' signals that are much much weaker.

Assumptions about Propagation: It is for me a reminder that we should always question our assumptions about a propagation mode when we hear a weak signal. Is a weak signal from someone say 200-400kms away on 28/40/50 MHz really tropo, short skip Sporadic-E or via Sporadic-E backscatter?

When we look at those FT8 or WSPR maps at the end of the day, how were we hearing all of those stations in the 200km-500km skip zone? Meteor Scatter? Tropo? Back-Scatter? I think the real picture is a lot more complicated than we assume.

Practical Application: It's all very well wondering about the propagation mode but most people will want to know what is the practical application? Imagine say you are a serious 50 MHz station and you want to work a new country which is only 400kms away and there are mountains in the way. You should never assume that just pointing your beam at a wanted station will always result in a stronger signal. If the signal is weak but constant then it may be via backscatter and you'll have to look for the direction which gives the strongest signals.

Addendum

For Reference: This map from DXMaps shows the suggested maximum usable frequency (MUF) at around 12:00 UTC on the 19th of  May.

It clearly shows one area over the south of England. Note however that this map is generated by users reports and areas of Sporadic-E out over the ocean are not shown. There could be an intense area to the west of Ireland and it would go unreported.

This was the Jet Stream at the time...

Changes in the direction of the Jet Stream are associated with Sporadic-E openings.

Data: Just for my own benefit, I've kept a list of the PI4 decodes below.

40M 10:52 UTC EI1CAH PI4: S/N=-26 dB Q=22 T=0.05 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 10:54 UTC EI1CAH PI4: S/N=-26 dB Q=48 T=0.05 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 10:56 UTC EI1CAH PI4: S/N=-26 dB Q=50 T=0.03 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:00 UTC EI1CAH PI4: S/N=-26 dB Q=52 T=0.03 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:02 UTC EI1CAH PI4: S/N=-26 dB Q=48 T=0.05 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:04 UTC EI1CAH PI4: S/N=-26 dB Q=46 T=0.05 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:06 UTC EI1CAH PI4: S/N=-26 dB Q=50 T=0.03 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:08 UTC EI1CAH PI4: S/N=-26 dB Q=44 T=0.03 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:10 UTC EI1CAH PI4: S/N=-26 dB Q=56 T=0.02 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:12 UTC EI1CAH PI4: S/N=-26 dB Q=38 T=0.02 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:14 UTC EI1CAH PI4: S/N=-26 dB Q=34 T=0.00 s F=-21 Hz Carrier: F= Hz C/N= dB
40M 11:16 UTC EI1CAH PI4: S/N=-26 dB Q=48 T=0.02 s F=-21 Hz Carrier: F= Hz C/N= dB
40M 11:18 UTC EI1CAH PI4: S/N=-26 dB Q=62 T=0.00 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:20 UTC EI1CAH PI4: S/N=-26 dB Q=62 T=0.03 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:22 UTC EI1CAH PI4: S/N=-26 dB Q=58 T=0.02 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:24 UTC EI1CAH PI4: S/N=-26 dB Q=42 T=0.02 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:26 UTC EI1CAH PI4: S/N=-26 dB Q=48 T=0.00 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:28 UTC EI1CAH PI4: S/N=-26 dB Q=68 T=0.00 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:30 UTC EI1CAH PI4: S/N=-26 dB Q=52 T=0.00 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 11:32 UTC EI1CAH PI4: S/N=-26 dB Q=64 T=-0.02 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:34 UTC EI1CAH PI4: S/N=-26 dB Q=78 T=0.00 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:36 UTC EI1CAH PI4: S/N=-23 dB Q=72 T=-0.02 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:38 UTC EI1CAH PI4: S/N=-26 dB Q=76 T=-0.02 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:40 UTC EI1CAH PI4: S/N=-25 dB Q=64 T=-0.02 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:42 UTC EI1CAH PI4: S/N=-24 dB Q=74 T=-0.02 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:44 UTC EI1CAH PI4: S/N=-24 dB Q=56 T=-0.03 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:46 UTC EI1CAH PI4: S/N=-23 dB Q=62 T=0.36 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:48 UTC EI1CAH PI4: S/N=-24 dB Q=68 T=0.34 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:50 UTC EI1CAH PI4: S/N=-24 dB Q=74 T=0.34 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:52 UTC EI1CAH PI4: S/N=-25 dB Q=82 T=0.34 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:54 UTC EI1CAH PI4: S/N=-24 dB Q=82 T=0.34 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:56 UTC EI1CAH PI4: S/N=-25 dB Q=68 T=0.36 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 11:58 UTC EI1CAH PI4: S/N=-24 dB Q=86 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:00 UTC EI1CAH PI4: S/N=-23 dB Q=76 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:02 UTC EI1CAH PI4: S/N=-23 dB Q=68 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:04 UTC EI1CAH PI4: S/N=-22 dB Q=80 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:06 UTC EI1CAH PI4: S/N=-22 dB Q=74 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:08 UTC EI1CAH PI4: S/N=-22 dB Q=60 T=0.32 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:10 UTC EI1CAH PI4: S/N=-22 dB Q=72 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:12 UTC EI1CAH PI4: S/N=-22 dB Q=82 T=0.32 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:14 UTC EI1CAH PI4: S/N=-24 dB Q=78 T=0.30 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:16 UTC EI1CAH PI4: S/N=-23 dB Q=88 T=0.30 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:18 UTC EI1CAH PI4: S/N=-23 dB Q=82 T=0.31 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:20 UTC EI1CAH PI4: S/N=-24 dB Q=72 T=0.29 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:22 UTC EI1CAH PI4: S/N=-24 dB Q=76 T=0.30 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:24 UTC EI1CAH PI4: S/N=-22 dB Q=72 T=0.29 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:26 UTC EI1CAH PI4: S/N=-24 dB Q=66 T=0.30 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:28 UTC EI1CAH PI4: S/N=-23 dB Q=82 T=0.29 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:30 UTC EI1CAH PI4: S/N=-23 dB Q=64 T=0.29 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:32 UTC EI1CAH PI4: S/N=-24 dB Q=74 T=0.27 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:34 UTC EI1CAH PI4: S/N=-24 dB Q=60 T=0.27 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:36 UTC EI1CAH PI4: S/N=-25 dB Q=58 T=0.25 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:38 UTC EI1CAH PI4: S/N=-24 dB Q=64 T=0.27 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:40 UTC EI1CAH PI4: S/N=-24 dB Q=46 T=0.27 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:42 UTC EI1CAH PI4: S/N=-25 dB Q=56 T=0.24 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:44 UTC EI1CAH PI4: S/N=-26 dB Q=46 T=0.24 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:46 UTC EI1CAH PI4: S/N=-23 dB Q=54 T=0.25 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:48 UTC EI1CAH PI4: S/N=-22 dB Q=86 T=0.27 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 12:50 UTC EI1CAH PI4: S/N=-20 dB Q=84 T=0.25 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:52 UTC EI1CAH PI4: S/N=-13 dB Q=88 T=0.24 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:54 UTC EI1CAH PI4: S/N=-22 dB Q=82 T=0.25 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:56 UTC EI1CAH PI4: S/N=-20 dB Q=76 T=0.24 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 12:58 UTC EI1CAH PI4: S/N=-13 dB Q=90 T=0.24 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:00 UTC EI1CAH PI4: S/N=-9 dB Q=98 T=0.22 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:02 UTC EI1CAH PI4: S/N=-9 dB Q=96 T=0.22 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:04 UTC EI1CAH PI4: S/N=-6 dB Q=94 T=0.22 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:06 UTC EI1CAH PI4: S/N=-23 dB Q=74 T=0.20 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:08 UTC EI1CAH PI4: S/N=-26 dB Q=60 T=0.20 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:10 UTC EI1CAH PI4: S/N=-26 dB Q=64 T=0.24 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:12 UTC EI1CAH PI4: S/N=-26 dB Q=52 T=0.22 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:14 UTC EI1CAH PI4: S/N=-26 dB Q=66 T=0.22 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:16 UTC EI1CAH PI4: S/N=-26 dB Q=60 T=0.22 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:18 UTC EI1CAH PI4: S/N=-24 dB Q=70 T=0.20 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:20 UTC EI1CAH PI4: S/N=-24 dB Q=66 T=0.20 s F=-9 Hz Carrier: F= Hz C/N= dB
40M 13:22 UTC EI1CAH PI4: S/N=-23 dB Q=82 T=0.20 s F=-15 Hz Carrier: F= Hz C/N= dB
40M 13:25 UTC EI1KNH PI4: S/N=-19 dB Q=64 T=0.12 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:26 UTC EI1KNH PI4: S/N=-20 dB Q=60 T=0.10 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:27 UTC EI1KNH PI4: S/N=-21 dB Q=56 T=0.08 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 13:30 UTC EI1KNH PI4: S/N=-19 dB Q=58 T=0.08 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:31 UTC EI1KNH PI4: S/N=-20 dB Q=48 T=0.10 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:32 UTC EI1KNH PI4: S/N=-22 dB Q=38 T=0.10 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:36 UTC EI1KNH PI4: S/N=-23 dB Q=36 T=0.08 s F=9 Hz Carrier: F= Hz C/N= dB
40M 13:37 UTC EI1KNH PI4: S/N=-24 dB Q=52 T=0.06 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:40 UTC EI1KNH PI4: S/N=-23 dB Q=40 T=0.04 s F=9 Hz Carrier: F= Hz C/N= dB
40M 13:41 UTC EI1KNH PI4: S/N=-24 dB Q=30 T=0.04 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:42 UTC EI1KNH PI4: S/N=-23 dB Q=42 T=0.04 s F=9 Hz Carrier: F= Hz C/N= dB
40M 13:45 UTC EI1KNH PI4: S/N=-25 dB Q=44 T=0.04 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:46 UTC EI1KNH PI4: S/N=-23 dB Q=46 T=0.06 s F=9 Hz Carrier: F= Hz C/N= dB
40M 13:47 UTC EI1KNH PI4: S/N=-22 dB Q=64 T=0.06 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:52 UTC EI1KNH PI4: S/N=-24 dB Q=34 T=0.07 s F=9 Hz Carrier: F= Hz C/N= dB
40M 13:55 UTC EI1KNH PI4: S/N=-24 dB Q=30 T=0.07 s F=3 Hz Carrier: F= Hz C/N= dB
40M 13:57 UTC EI1KNH PI4: S/N=-26 dB Q=30 T=0.09 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:00 UTC EI1KNH PI4: S/N=-25 dB Q=50 T=0.09 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:01 UTC EI1KNH PI4: S/N=-26 dB Q=62 T=0.07 s F=-3 Hz Carrier: F= Hz C/N= dB
40M 14:02 UTC EI1KNH PI4: S/N=-26 dB Q=36 T=0.09 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:05 UTC EI1KNH PI4: S/N=-26 dB Q=38 T=0.03 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:06 UTC EI1KNH PI4: S/N=-26 dB Q=48 T=0.01 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:07 UTC EI1KNH PI4: S/N=-26 dB Q=38 T=0.01 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:10 UTC EI1KNH PI4: S/N=-26 dB Q=46 T=0.01 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:11 UTC EI1KNH PI4: S/N=-26 dB Q=44 T=0.03 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:12 UTC EI1KNH PI4: S/N=-26 dB Q=38 T=0.01 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:15 UTC EI1KNH PI4: S/N=-25 dB Q=42 T=0.22 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:16 UTC EI1KNH PI4: S/N=-26 dB Q=46 T=0.19 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:17 UTC EI1KNH PI4: S/N=-26 dB Q=62 T=0.21 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:20 UTC EI1KNH PI4: S/N=-25 dB Q=46 T=0.19 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:21 UTC EI1KNH PI4: S/N=-24 dB Q=60 T=0.19 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:22 UTC EI1KNH PI4: S/N=-25 dB Q=46 T=0.19 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:25 UTC EI1KNH PI4: S/N=-24 dB Q=64 T=0.17 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:26 UTC EI1KNH PI4: S/N=-23 dB Q=66 T=0.19 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:27 UTC EI1KNH PI4: S/N=-22 dB Q=58 T=0.17 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:30 UTC EI1KNH PI4: S/N=-22 dB Q=76 T=0.19 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:32 UTC EI1KNH PI4: S/N=-22 dB Q=66 T=0.19 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:35 UTC EI1KNH PI4: S/N=-19 dB Q=68 T=0.17 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:36 UTC EI1KNH PI4: S/N=-20 dB Q=76 T=0.17 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:37 UTC EI1KNH PI4: S/N=-20 dB Q=80 T=0.17 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:40 UTC EI1KNH PI4: S/N=-19 dB Q=72 T=0.16 s F=3 Hz Carrier: F= Hz C/N= dB
40M 14:41 UTC EI1KNH PI4: S/N=-19 dB Q=82 T=0.16 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:42 UTC EI1KNH PI4: S/N=-19 dB Q=94 T=0.16 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:45 UTC EI1KNH PI4: S/N=-19 dB Q=76 T=0.17 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:46 UTC EI1KNH PI4: S/N=-18 dB Q=80 T=0.16 s F=9 Hz Carrier: F= Hz C/N= dB
40M 14:47 UTC EI1KNH PI4: S/N=-17 dB Q=80 T=0.16 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:04 UTC OZ7IGY PI4: S/N=-26 dB Q=46 T=0.00 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:35 UTC EI1KNH PI4: S/N=-17 dB Q=68 T=0.11 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:36 UTC EI1KNH PI4: S/N=-16 dB Q=86 T=0.11 s F=3 Hz Carrier: F= Hz C/N= dB
40M 15:37 UTC EI1KNH PI4: S/N=-17 dB Q=72 T=-0.12 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:40 UTC EI1KNH PI4: S/N=-17 dB Q=76 T=-0.12 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:41 UTC EI1KNH PI4: S/N=-19 dB Q=64 T=-0.12 s F=3 Hz Carrier: F= Hz C/N= dB
40M 15:42 UTC EI1KNH PI4: S/N=-16 dB Q=74 T=-0.13 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:45 UTC EI1KNH PI4: S/N=-18 dB Q=80 T=-0.12 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:46 UTC EI1KNH PI4: S/N=-17 dB Q=80 T=-0.12 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:47 UTC EI1KNH PI4: S/N=-17 dB Q=62 T=0.54 s F=3 Hz Carrier: F= Hz C/N= dB
40M 15:50 UTC EI1KNH PI4: S/N=-17 dB Q=86 T=0.52 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:51 UTC EI1KNH PI4: S/N=-19 dB Q=72 T=0.52 s F=3 Hz Carrier: F= Hz C/N= dB
40M 15:52 UTC EI1KNH PI4: S/N=-18 dB Q=74 T=0.52 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:55 UTC EI1KNH PI4: S/N=-16 dB Q=84 T=0.52 s F=3 Hz Carrier: F= Hz C/N= dB
40M 15:56 UTC EI1KNH PI4: S/N=-15 dB Q=86 T=0.50 s F=9 Hz Carrier: F= Hz C/N= dB
40M 15:57 UTC EI1KNH PI4: S/N=-15 dB Q=82 T=0.50 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:00 UTC EI1KNH PI4: S/N=-16 dB Q=88 T=0.48 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:01 UTC EI1KNH PI4: S/N=-15 dB Q=90 T=0.48 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:02 UTC EI1KNH PI4: S/N=-17 dB Q=80 T=0.47 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:05 UTC EI1KNH PI4: S/N=-14 dB Q=90 T=0.49 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:06 UTC EI1KNH PI4: S/N=-15 dB Q=90 T=0.49 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:07 UTC EI1KNH PI4: S/N=-15 dB Q=84 T=0.49 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:10 UTC EI1KNH PI4: S/N=-15 dB Q=76 T=0.67 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:11 UTC EI1KNH PI4: S/N=-14 dB Q=92 T=0.68 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:12 UTC EI1KNH PI4: S/N=-15 dB Q=86 T=0.67 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:15 UTC EI1KNH PI4: S/N=-16 dB Q=78 T=0.68 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:16 UTC EI1KNH PI4: S/N=-16 dB Q=70 T=0.67 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:17 UTC EI1KNH PI4: S/N=-13 dB Q=96 T=0.68 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:20 UTC EI1KNH PI4: S/N=-15 dB Q=90 T=0.47 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:21 UTC EI1KNH PI4: S/N=-15 dB Q=86 T=0.45 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:22 UTC EI1KNH PI4: S/N=-17 dB Q=72 T=0.47 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:25 UTC EI1KNH PI4: S/N=-17 dB Q=70 T=0.40 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:26 UTC EI1KNH PI4: S/N=-17 dB Q=66 T=0.40 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:27 UTC EI1KNH PI4: S/N=-16 dB Q=82 T=0.38 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:30 UTC EI1KNH PI4: S/N=-17 dB Q=74 T=0.40 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:31 UTC EI1KNH PI4: S/N=-20 dB Q=68 T=0.38 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:32 UTC EI1KNH PI4: S/N=-19 dB Q=54 T=0.36 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:35 UTC EI1KNH PI4: S/N=-18 dB Q=68 T=0.48 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:36 UTC EI1KNH PI4: S/N=-17 dB Q=82 T=0.48 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:37 UTC EI1KNH PI4: S/N=-20 dB Q=66 T=0.43 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:40 UTC EI1KNH PI4: S/N=-20 dB Q=70 T=0.41 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:41 UTC EI1KNH PI4: S/N=-21 dB Q=54 T=0.41 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:42 UTC EI1KNH PI4: S/N=-19 dB Q=76 T=0.41 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:45 UTC EI1KNH PI4: S/N=-19 dB Q=74 T=0.43 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:46 UTC EI1KNH PI4: S/N=-21 dB Q=68 T=0.40 s F=9 Hz Carrier: F= Hz C/N= dB
40M 16:47 UTC EI1KNH PI4: S/N=-20 dB Q=56 T=0.42 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:50 UTC EI1KNH PI4: S/N=-20 dB Q=44 T=0.40 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:51 UTC EI1KNH PI4: S/N=-21 dB Q=52 T=0.41 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:52 UTC EI1KNH PI4: S/N=-22 dB Q=38 T=0.38 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:55 UTC EI1KNH PI4: S/N=-24 dB Q=44 T=0.38 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:56 UTC EI1KNH PI4: S/N=-21 dB Q=58 T=0.38 s F=3 Hz Carrier: F= Hz C/N= dB
40M 16:57 UTC EI1KNH PI4: S/N=-24 dB Q=50 T=0.40 s F=9 Hz Carrier: F= Hz C/N= dB