Tuesday, March 21, 2017

9N7EI (Nepal) worked on 30m & 40m

In mid-March of 2017, there was an Irish expedition to Nepal where the 12 man team operated as 9N7EI. They were on air from the 10th of March to the 19th of March with a stated objective of reaching 30,000 contacts. In the end, they managed 30,384 with 12,025 unique call signs.

This is a breakdown of their contacts by band...

With the Solar Flux down around 70 and with no sunspots on the sun, there were very poor conditions on 28MHz. The maximum number of contacts were logged on 18 MHz.

What's also noticeable was just how important CW is when the conditions are poor with the mode making up 57% of all contacts.

From my own experience, the signals from 9N7EI were pretty weak and the pile ups seemed huge. It might be fine for someone with a beam and an amplifier but it's another story with just an 80m dipole at a low height and 100 watts.

I listened on and off for them over the first week but I had no hope of cracking any pile up. I really didn't have any interest in sitting at the radio for an hour calling in the hope I'd be heard. It was more of a case that while it would be nice to work them, I wouldn't be too bothered if I didn't.

On the 17th of March, the conditions on the HF bands seemed above average. I had worked 5U5R on 17m and 9G5X on 12m during the afternoon and later that night, I came across 9N7EI on 30m calling CQ at 22:09 UTC. The CW signal was really weak and was dipping in and out of the noise. I put on the headphones, waited for their signal to come out of the noise and I got them first call.

Just after midnight, I came across them again on 40m. Again, weak and buried in the noise. I had noticed before that when I was doing ground wave experiments with EI6AK, my signal on 40m with a CB vertical half wave seemed to be reasonable. It seems to work as a short loaded vertical. So I tried it and 9N7EI seemed slightly stronger on receive. I matched it with the ATU and again, I played the waiting game and called them when they came out of the noise. It took a few calls but I got them eventually. I must have been really weak at their end so fair play to whoever was there for listening to signals buried in the noise.

I think that because the band was just about open, the signals were coming in at a low angle. The high angle of the 80m dipole wasn't great so the vertical CB antenna had the slight edge with the lower angle of radiation. The gain of the antenna must have been several dB down though on a proper 40m vertical. A quarter wave on 40m is 10m. The CB half wave vertical antenna is 5 metres in length and it has no ground plane system to speak of.

This is the VoaCap prediction for the band at the time of the contacts. Seems like the path between EI and 9N wasn't the best.

Three things struck me about the contact.

1) The signals were so weak that SSB would have been impossible. It was only possible by using CW.

2) The contacts were at 22:09 and 00:14. A lot of the Europeans might have gone to bed at that stage which helped.

3) I wonder if people are prepared to listen to a signal that is buried in the noise. Sometimes it seems as if people are just attracted to the strongest signals....a bit like moths to a flame. How many will sit and listen to a signal buried in the noise and wait for it to get strong enough? This thought struck me later that day when I noticed a EA9/DL... station with a huge pile up. A bit too big for just an EA9 station. The one thing that he had was a big signal.

In the end, a total of 71 EI stations managed to work 9N7RI with several on different bands and modes. They are shown below......

Expedition website... https://9n7ei.com/

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