G/LD-017 Red Screes

Given the biblical weather we had here yesterday in the Lake District - heavy rain and flooding - the last thing on my mind was the possibility of a SOTA activation. However, having had a lazy start to Sunday I checked the weather report and was surprised of the modified prediction of light winds and no rain. Sunshine even later! So I hurriedly topped up a LiFePo4 battery and threw my usual SOTA kit into a rucksack. Arriving possibly quite unusually by motorbike at the Kirkstone Inn car park I took the 45 minute stone staircase to the summit. I was expecting it to be wet under foot but most of the stone was dry and easy.

I setup at the tarn near the trig and got going quickly on 40m having found that I still have issues with the 80m section of my linked dipole. Cracking run of 20 chasers on 40m mostly in Europe but some UK stations. Two S2S’s initially with OE5REO/P on OE/OO-345 and HB9CRY/P on HB/LU-010.

Moving to 20m band conditions were still good even though there was a Scandinavian competition on. Moving to 2m brought in some local chasers and two contacts on C4FM. Back to 20m another two S2S were completed with OE9HRV/P on OE/VB-465 and HB9DIZ/P on HB/LU-025.

It was time to brave a CW contact - I’m still very much a noob - in then end I thought I would be able to copy DL0FUL/P - a club callsign - on 40m. It was going well until the MCHF rig totally hung and required a reboot which lost the frequency, but at least this was after callsigns and signal reports were exchanged. Not brave or competent enough yet to try a CW activation. I chased one SOTA activator last week - but at least chasing you get a chance to copy the activators callsign a few times to ensure correct.

I then noticed the spot by Herbert @OE9HRV on O/VB-465 saying ‘state side is open’ (what a great thing to put in a spot Herbert!) so I moved back to 20m for another run including Phillip @VE1WT which was great!

With the SOTABeam 10m compact mast strong enough to support both the HF antenna and the Slim-G 2m/70cm antenna I was fortunate enough to catch Viki @M6BWA calling CQ on 2m from G/SB-007. Earlier I had noticed her alert and used the Solwise Wireless Elevation Tool to find that it was pretty much line-of-sight from Red Screes (skirting over the top of a North Pennine summit). So we managed both a 2m and 70cm QSO without any difficulty.

I then talked to a couple of others calling CQ on 2m including MM6JIG in Wigtown, Scotland, for whom I was his first contact ever as an M6!

To top all this the sun came out and I happily donned my sunglasses and took the opportunity to take some great photos. Roll on the winter bonus!

Regards, Mark.
M0NOM
Photo Album

Date: 14/Oct/2018 Summit: G/LD-017 (Red Screes) Call Used: M0NOM/P Points: 0 Bonus: 0

Time Call Band Mode Notes
11:23z DJ5AV 7MHz SSB
11:23z LA5WNA 7MHz SSB
11:24z M3FEH 7MHz SSB
11:26z EA1DFP 7MHz SSB
11:26z G0TDM 7MHz SSB
11:28z 2E0WDX/M 7MHz SSB Vin Newcastle
11:29z EA2DT 7MHz SSB
11:30z DL5DB 7MHz SSB
11:30z SM7DIE 7MHz SSB
11:31z OE5REO/P 7MHz SSB
11:32z IK2LEY 7MHz SSB
11:32z LB6WG 7MHz SSB
11:34z M0MDA 7MHz SSB
11:34z OE5HDN 7MHz SSB Henri
11:34z ON4VT 7MHz SSB
11:36z HB9CRY/P 7MHz SSB
11:37z HB9DHA 7MHz SSB
11:40z F6FTB 7MHz SSB
11:41z OE7HPI 7MHz SSB qrp
11:45z OH0X 14MHz SSB Scandanavian Contest RX: 1751 TX: 0001
11:48z EU6DX 14MHz SSB
11:48z OH3GZ 14MHz SSB
11:49z G0TDM 14MHz SSB
11:50z S57WJM 14MHz SSB Mitha JN76HA Slovenia
11:54z G0HRT 144MHz FM Rob
11:57z G0TDM 144MHz FM
11:59z G1OHH 144MHz FM
12:03z GM4WHA 144MHz FM
12:04z M6MOS 144MHz FM Malcolm
12:06z G7CDA 144MHz FM
12:06z G10HH 144MHz DV 46.8km
12:06z G7CDA 144MHz DV 45.2 km
12:39z OE9HRV/P 14MHz SSB
12:42z HB9DIZ/P 14MHz SSB
13:03z DL0FUL/P 10MHz CW Nr Kassel
13:21z DB7MM/P 14MHz SSB
13:22z EA2DT 14MHz SSB
13:22z F5JKK 14MHz SSB
13:22z OE6GND 14MHz SSB
13:23z SP9AMH 14MHz SSB
13:24z VE1WT 14MHz SSB
13:25z HA7WA 14MHz SSB
13:25z SP9ETA/P 14MHz SSB
13:29z S57ILF 14MHz SSB
13:35z M6BWA/P 144MHz FM
13:39z M6BWA/P 433MHz FM
13:47z MW0BYT 144MHz FM
13:51z MM6JIG 144MHz FM Wigtown 85 yrs old
14:03z MW3KML 144MHz FM Kevan Mould
14:36z IZ5DRL 14MHz SSB Mario 2ele beam 500w Expert Amp TS990

14 Likes

Hi Mark,
Lovely photos. Good WX and good use of the available band conditions. It’s about time 7 MHz did some work. You bit the bullet and did CW too.

Thanks for Solwise. Never heard of it until now but what a gift! I have been looking for a replacement for the site we all used years ago for that purpose.
73, John

No worries John, lets hope they don’t work out it is being used by Amateur Radio folk too soon! :ok_hand:

Mark. M0NOM

Having heard from the Microwavers just a couple of days ago that interest in such elevation tools was minimal at best, I was tempted to delete the new elevation profile tool (still in development) in the new, not-yet published, SMP as a waste of my time. And now I read here that such tools are actually being used.

So, I fired up the tool and made an elevation profile between G/LD-017 and G/SB-007 to see how that would look in comparison to the one from Solwise. Here’s how it looked:

and here’s the equivalent one from the Solwise site:

So, pretty much the same, right?

Now, here’s the same profile (from the new SMP), showing in addition the first Fresnel zone for the 2-meter band:

And here’s the same profile, but now adding in the earth’s curvature between the two summits (remember the earth gets in the way somewhat over distance :smile:):

and the same with the 2-meter band Fresnel zone:

Now, I’ll be the first to admit that I don’t know anything worth knowing about propagation in the VHF++ bands, so I’ll leave interpretation of these charts to others better qualified. But you may agree with me that the results are intriguing.

Rob DM1CM

3 Likes

Hi Rob. Well I can confirm that I use elevation tools all the time :wink:

Even more interesting is the final image with Earth curvature taken into account! Clearly there is a huge difference between the ‘flat Earth’ model and an accurate one. As soon as I saw the image taking into account Earth curvature I immediately question any of the elevation profiles I have previously created!

Looks like a great tool to me.
Regards, Mark. M0NOM

Wow that is a very cool feature.

I also “discovered” the mapping feature to show all peaks within a donut that seemed useful for pursuing uWave awards in being able to set the interior of a donut to say 50km on a known chaser.

Paul M0SNA aka W6PNG

That was a feature actually requested a couple of years ago by a microwaver in the US - I don’t remember right now who that was…

Rob

Clearly a very smart person!

1 Like

Rob, just out of interest, could you plot a profile with earth curvature between the following two locations please?

  • 54.369195, -2.899244 (Lickbarrow Road Windermere)
  • and GW/NW-001

According to the Solwise tool this is line of sight but I’ve never been able to chase someone on Snowdon on 2m from that location (it is 5 mins from my QTH and the highest spot I can get to quickly). I suspect your tool will show something very different.

image

…or someone who loves donuts :wink:

Really interesting feature, Rob…

OK, it’s the other way round, since I took your address first, but no matter: as near as I could get it, here’s the flat earth version:

…and with earth bulge/curvature:

…and with 1st Fresnel zone for 2 meters:

So, as I understand it,

The first zone must be kept largely free from obstructions to avoid interfering with the radio reception. However, some obstruction of the Fresnel zones can often be tolerated. As a rule of thumb, the maximum obstruction allowable is 40%, but the recommended obstruction is 20% or less. (Wikipedia)

So, you’re in for a bit of a struggle there… EDIT - BUT, see below…

Rob

I believe his name was Duncan…:rofl:

1 Like

That path should be fairly easy to work via normal troposcatter on 2m SSB with smallish Yagis at both ends. But simple verticals and FM may make it really difficult. You would need to get the antennas clear of the ground, say 3-4m. Positioning the Snowdown end on the edge of any sharp drops would help. Mark’s QTH looks rubbish with lots of vegetation and no obvious ground gain to be had. Getting the antenna well clear should produce a big improvement.

Should be (for various definitions of should be) possible with a bit of antenna choice and planning. Very dodgy for someone running up to the local high spot with a handy though.

Right - this is some of the stuff I’m largely unaware/ignorant of, so it’s good to hear from somebody with experience in these matters.

(Hopefully not teaching you to suck eggs here Rob)

Troposcatter is available nearly all the time at VHF and is the normally mode used for paths beyond LOS. Typically there will be a volume of troposphere a few km above ground that both stations can see and dirt/moisture/stuff in that volume of atmosphere will scatter some RF. You need a directional antenna, some watts and a decent sensitivity which can discount FM and rubber ducks in many cases and makes SSB a better choice.

Tropoducting is when you get layers of air at a different temperature trapped between other layers. This is when you get significant long range propagation at VHF and up. Typically as a result of prolonged periods of high pressure starting to decline. To benefit, antennas needs to see the duct opening at both ends and can result in 1000’s of km of propagation. Moving height only a small amount or position a few kms can result in the duct not being visible. ISTR reading the duct depth needs to be 10-20 wavelengths high to work. So quite deep for 2m and that requires more extreme conditions that for higher bands where small ducts form more easily and ducting on 6m is much less common. Ducts form all the time over long water paths and cause havoc to commercial links, they normally need to have multiple antennas and different heights (maybe one antenna 50m higher than the other) and use automatic antenna diversity to maintain comms as the ducts form and break up.

So, I guess you measure this with a duct tape?

Well, your image is amazing Rob and quite succinctly explains why I never had a hope of getting a contact! :grinning: So now we have hills at both ends and a bit of ocean to get through. I do have a delta quad antenna that works well which does a good job of sucking a signal in but I’m guessing that the average activator of Snowdon is going to be either on a handheld of a vertical roll-up of some description.

I’m quite staggered that the curvature is that much mind. Well, I’m really looking forward to the tool being available, it’ll be great to have a play and work away from my QTH to find somewhere suitable.

Cheers, Mark.

Well, let’s not forget that the vertical scale on those diagrams is much exaggerated. The actuall bulge/curvature is just under 530 meters over the distance of 160-odd kilometers. Here’s another view of that:

where the vertical scale is less exaggerated.

So, you’re going to have to factor in this tropo stuff as Andy suggests, and with a couple of decent antennas at both ends, and a bit of extra height (try some Gary Glitter platforms - I’m sure Tom @M1EYP could loan you a pair), you should manage the link OK. :wink:

Oh I love the baiting there :ok_hand: As it happens, to go full circle, I heard Tom when coming down from Red Screes - a small world eh? He even returned my callsign, but was mobile on the M6/M55 and couldn’t hear me again.

Your images remind me of the Father Ted Cow sketch… where I am doing a great Dougal impression!

I think the solution is obvious - pick one big hill round here and get a S2S instead. I’ll bet there are no issues once I’m up Coniston Old Man. Maybe I can borrow his shoes as well…

Regards, Mark

Looks like the model needs a bit of work. k should be 4/3, not 1. Propagation Tutorial - Refraction and ducting