Other SOTA sites: SOTAwatch | SOTA Home | Database | Summits | Video | Photos | Shop | Mapping | FAQs | Facebook | Contact SOTA

Success at Mt. Artxueta EA2/NV-032 by EA2IF/P on 19/12/2021

First of all, I want to dedicate this successful activation to the glory and memory of a well known EA2 chaser who passed away on Friday night. He was José-Luis EB2JU.

I just learnt this morning about José-Luis passing and decided to carry out my first 2021-22 winter bonus activation in his memory. This also gave me the chance to escape the persistent low cloud/fog in Pamplona not letting the temperatures rise more than 0º, 1º, 2º C all day throughout the whole week. Up in the mountains, the sky was blue and the sunshine helped to overcome much better the low temperature of about 1º, 2º C.

I have been feeling a bit unwell lately with some pains, so I haven’t been sleeping too well lately and I’ve been feeling a bit weak. However, with the help of some “legal drugs” I’ve been able to keep the pains a bit under control today and I decided to attempt a 4 pointer (+3 of winter bonus) which can be reached by car in summer, but not today with thick snow patches covering big parts of the road. However, the hike from the parking place to the summit is trivial and I covered it in about 15 minutes, making a short cut instead of using the boring zig-zagging road and taking care of not hiking much over the snow patches.
I had my new ice spikes with me, but the snow patches were too small and the snow wasn’t hard enough as to make wearing the ice spikes worthwhile.

This activation had a technical purpose too.
Heinz @HB9BCB kindly offered himself some days ago to simulate on EZNEC the antenna I most use for SOTA and I asked him to find out whether this antenna had any directivity, as I was kind of guessing.
Heinz’s study was very detailed and extremely interesting, although he is still working on it after his findings and my on-field testing.

EZNEC simulations proved that instead of the 10m long or 14m long sloping wire to a 9:1 unun transformer with a 5,5m long elevated counterpoise wire I was using, a 7m long sloping wire at an angle of about 45º and a 2.1m long horizontal elevated wire fed directly by the coax without using any transformer, would be tunable on all bands and would have a better directivity on the preferred bands of 20 and 30m.

I built Heinz’s proposed antenna immediately and tested it on Monday during my activation of Mt. Erreniega EA2/NV-092. I setup the antenna that day beaming to the North-East and the signals from the East were just booming. My received signal reports were also pretty good. However, I found my MFJ-941B ATU was only capable of finding a good 1:1 SWR on 12, 20 and 30m. The last 2 bands are the ones I used during my activation.

I shared my findings with Heinz and he came back to me suggesting that there might be Common Mode Currents traveling back through the 1m long coax braid I use, thus bothering or causing troubles to the FT-817 SWR meter. So I got 4 ferrite clips I had in a drawer of my desk, put them on the feeding coax of my SOTA-kit, and got just ready for a test as soon as possible.

This was as soon as today. The purpose of todays activation, given that it was going to be an afternoon activation, was setting up beaming West in order to test directivity or enhancement towards a chosen direction and also checking whether the ferrite clips would do something positive or not towards the ATU being able to find a perfect 1:1 SWR match.

I enjoyed these nice views during the ascent:

My car can be seen down there:

At the summit, I chose this spot looking to the North-West for my setup:

The inner of the coax gets connected to the 7m long red sloping wire and the braid to the 2.1m long horizontal blue wire. See the following closer look of the feed point. Notice the 4 ferrites clipped on the RG58 coax:

The telescopic fishing rod is 7m long and I estimate the sloper angle very close to 45º, while the shorter leg of this OCF antenna remains horizontal about 0,8-1m above the ground.

The activation was improvised and there wasn’t an alert, so I selfspotted with my smartphone browser using SOTAwatch, as something has changed on the SOTA-spotter APP and I wasn’t able to find how to selfspot. I’ll have to find out…

I started my activation on 30m, where I had a good run of 23 QSOs in 32 minutes, including my only S2S of the day thanks to Mark @M0NOM.

Then I passed to 20m, where I logged 41 QSOs in 1 hour and 10 minutes, including the amazing number of 11 Trans-Atlantic QSOs with the USA and Canada.

These 2 were the bands I could tune and use during my first test on Monday, so I now held my breath and QSYed to 40m. To my surprise and great joy, I could easily tune on this band for a perfect 1:1 SWR and I logged 20 QSOs in 20 minutes.

Then I QSYed to 60m to find that my ATU was again capable of easily tuning for a perfect 1:1 SWR. I wanted to CQ on 60m, but the Sun was too low and I was starting to feel a bit cold, despite the 3 hats, 6 top layers and 2 trousers.

Before QRT, I tried to tune the antenna with my MFJ ATU on 17, 15 and 12m with no luck, but I could successfuly find a perfect match on 10m.

The activation was very successful from my point of view, as I not only could log 84 QSOs in about 130 minutes, including 11 Trans-Atlantic QSOs with USA and Canada…

…but also confirmed Heinz’s fears about the CMC and proved that the 4 ferrite clips made a real difference converting this antenna in my new antenna for SOTA, with less length of wire, so easier to deploy and mainly wind up back and also without a 9:1 unun or any other type of transformer, which will contribute to reducing the rucksack weight.

Regarding the bands where my ATU wasn’t able to tune this antenna, we’ll try to figure out what the best solution can be, as I’d really like to have 17, 15 and 12m in my portfolio.

Heinz and I haven’t fully yet decided the name for this new antenna but it will probably include 9.1 (due to the 7m and 2.1m long pieces of wire), OCF (due to the way it’s fed off center) and something like Sloping-L, Sloping wire or similar. We’ll let you know.

I hope you found this of interest.
Right before starting my descent I took 4 pictures with which I’ve put together this panoramic view with the Sun just about to leave us:

Thanks very much dear chasers for your calls and QSOs, particularly those from across the Pond, who really made my day.
I’ll be looking forward to copying you all again soon from a SOTA.
73 and my very best wishes of a Merry Christmas to you all.

Guru

28 Likes

Hello Guru, thanks for your activation report and great photos. Your comments about the changes to your antenna set-up was very interesting and what you learnt. Sorry to hear about José-Luis EB2JU.

Stay safe Guru and hope you are getting better.

All the best for Xmas and HNY to you and your family.

Cheers to you :beers: :champagne:

Take care, Geoff vk3sq

1 Like

Many thanks for another trans-Atlantic SOTA QSO. Maybe I will try this new antenna on a summit and see if we can make it an s2s next time. Best wishes for holidays. Stay well & 73! Mike, WB2FUV

1 Like

Thanks for your call, Mike. Always a pleasure to work you either as a chaser or an activator. Let me know if you build and try this antenna. I haven’t published the EZNEC graphs showing its directivity because it’s Heinz’s HB9BCB work and I prefer him to publish that info here when he wants and only in case he wants to. But it’s amazing the directivity compared to the lengths of wire to the 9:1 unun I had been using up to now.
BTW, I’ve just editted my report and posted a close look picture of the feed point, as well as the QSOs map. I knew I had WB6POT in my log, but I didn’t know he actually was in California. Wow! This just makes yesterday’s success even greater!
73,

Guru

1 Like

Excellent reporting, Guru. Very interesting. Thanks for sharing.

And very nice views from the mount Artxueta. Looking for the sun. Fortunately for our area, after 21 consecutive days of rain, we can now see blue skies.

73

2 Likes

That was a very successful afternoon Guru, reaching the west coast of the US is an impressive achievement.

The antenna design is very interesting. I’ve only recently recognised having the counterpoise or radial raised above the ground can be an improvement over putting it on the ground. I guess the design is a form of off centre fed dipole?
John

1 Like

I see it that way too, but the key is the configuration with the longer leg sloping at about 45° and the shorter horizontal and elevated, both aligned towards the preferred direction.

2 Likes

Hi Guru,
Thank you for the nice activation report.
Hope you will get better soon.
Your ice spikes, for the lighter work there exist micro spikes, may be interesting to you? See the following link:

Vy 73 HNY and X-Mas
Patrick ON4BCA

1 Like

Great report @EA2IF Guru. I have noticed that callsigns starting with K or W definitely stick out in CW as the prospect of DX beckons :wink: Oh, and having processed an ADIF file with a years worth of contacts recently for a ‘big gun’ ham in Europe I can confirm that even the big stations struggle with West Coast.

I have spikes here but have yet to wear them. This time last year I did the same route as yesterday in deep snow. I find generally that trail shoes with a wide-spaced grip suffice. Typically if some of the ‘stone staircases’ are covered in ice - the one situation the the trainers don’t work - the spikes don’t really help either. The caveat being this is the sort of terrain I am prepared to tackle in the winter!

The antenna design is intriguing, I love the idea of designing from the point of view of portability and speed of deployment. Look forward to the results.

Regards, Mark.

1 Like

These are the ones I just got this week and I had with me yesterday, but the snow was not hard enough and the patches were too small as to make the upheaval of fitting them to my boots worthwhile.
See these pictures of my just bought ice spikes:
imagen

imagen

73, Patrick, and Merry Christmas.

3 Likes

Guru,

Thanks for the detailed report and especially for the details regarding impedance matching with the MFJ-941B.

Because the antenna impedances to be expected on the bands 40-10 m are all quite moderate and the L and C values required to compensate for the (with the exception of 17 m) capacitive reactance are comparatively low and even very low with increasing frequency, it could be that the fine adjustment with the variable loading capacitor is very sharp.

Therefore, the following procedure could probably help:

  • start by matching the 20 m band

  • (then use the same L step or the one increased by ~ 1 uH on 17, 15 and 12 m)

  • At 17, 15 and 12 m only the antenna-side C should have to be varied very slightly by ~ 10-25 pF

  • At 10 m, an L step that is ~ 1.5 uH lower and an even a slightly lower C value should work.

In any case, it would be highly recommended to insert an efficient common-mode choke at the feed point (also to rule out possible incorrect measurements of the SWR meter).

The feed point shown below with integrated c-m choke was built for use with Up-and-Outer antennas and has also proven itself, for example, with a multi-band Up-and-Outer antenna on a 10 m mast at the SOTA 12 m Challenge 2013/14.

Of course, the (unprotected) Pico Balun Kit from SOTABEAMS (with 1 m RG58) could also be used.

BTW, It was never my intention to present and discuss this topic in great detail on this reflector - too time consuming and too little noteworthy. That’s why I originally chose the personal mail form. I hope you can understand this Guru.

Of course, I will be happy to send you the revised report on your antennas in the next few days. The same applies to the description of the 9.1 m sloping OCF wire antenna under the title “A compact 40-10 m OCF Random wire antenna”.

If you want, feel free to publish the reports on your website.

73 tks, Heinz


2 Likes

Hi Heinz,
Thanks for your feedback.

The variable loading capacitor position on those bands where I could tune to SWR 1:1 was quite sharp most of the times, but it was wide and enoughly defined to find it very easily.

I’ll try that although I tried it quite carefully yesterday without success on those mentionned bands.
I’ll also take note or even a picture of the variable capacitors and the inductor selector positions for each perfectly tuned band at the perfect match position.

I think I’ll probably build the c-m Choke 80-10m / 10W.

I fully understand your position on this and I have not any problem with it at all.

I now want to publicly thank you for your offer, very interesting study and conclusions, which have taken me to discover a smaller, lighter, easier to deploy and pack-up antenna with a greater directivity than the ones I had been using so far.

73 and Merry Christmas.

Guru

2 Likes

Hi Guru,

As always, I enjoyed your post and photos. This particular post included a bonus—plans for a very useful SOTA antenna which I bookmarked for future reference.

Best wishes and happy holidays!

2 Likes

Hello Guru, great antenna report. Interesting as that length is commonly used on vessels on the Marine frequencies, they are near the amateur bands. Hey - I worked you on 21/12/21 from a peak in the California desert. Thanks for the qso. Good luck with antenna effort. N6IZ

2 Likes