Activation void due to not being in activation zone

Hi All, just a quick heads up: I will be activating the summit of ’ Snowdon ’ GW/NW-001 this coming Saturday morning (25th Sept) at approximately 07:00 UTC +/- . I’ll be operating on 2m FM only, putting a call out on S20 and QSY’ing to a free frequency. I must apologise to all activators and chasers for my previous activation on Snowdon last Tuesday 21st Sept, due to the summit being busy, I used my SOTA goat app to make sure I was in the activation zone - the app gave out false information which meant my activation was void because I was not in the activation zone. I have not uploaded my log on the SOTA database, so if you could please discard this activation, that would be much appreciated. I plan to give the points back this Saturday, so please feel free to call into my SOTA station for 10 points and DO NOT use the SOTA goat app to find the activation zone in the future! Apologies again folks! 73, GW4BML Ben


Oh no @GW4BML thats a bugger after all the time it took me to get through to you, & you to get to the top. Ill try to get you again on Sat morning. Thanks for going back up again to the summit. :+1:

I know @M7CAD, sorry for the inconvenience caused. That stupid app caused me some problems, never mind, I’ll be back up on Sat morning subject to wx and please call in to get your deserved points, I’ll be listening for everyone. Thanks again :+1: GW4BML. Ben

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Would be interested to know what the error was. GPS elevation calculations are notoriously inaccurate unless the GPS receiver has been calculating its stuff for a reasonable time, eg an hour is enough but 5 minutes often isn’t. So even a dedicated GPS will give inaccurate elevation data for a while after being turned on. The map is always more reliable and finding where the 25m contour is on the map is preferable to depending on an electronic altimeter.

In other words, perhaps the app was not the problem, but the GPS in the iphone was. The app can only work correctly if it is given accurate elevation data by the GPS system in the phone.

Commiserations though, it’s disappointing to have to scratch an activation.

Hope the rerun is successful.

73 Andrew VK1DA/VK2UH

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Thank you very much for the information Andrew. After looking into it, I was definitely out of the activation zone, be it the iPhone or app details given to me. A rerun is the best and fingers crossed it will be successful.



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Hi Ben,

Thanks for the heads up, and respect for going back to do it again! I’ll delete my S2S record, but I still enjoyed the chase :o) Not sure that I’ll be able to catch you on Saturday, but best wishes anyway - I look forward to working you again before too long.

As per another thread, it would be really helpful if Apps and other tools flagged up a warning that determining AZ limits is entirely up to the activator on site. Any automated plotting is likely to be a rough guide at best.
I suspect that quite a few activators have been / will be mislead in this way.


Hi Adrian @G4AZS, thank you very much for your understanding. It was a pleasure having our first S2S which I enjoyed as well. It’s just a pity I cannot upload my log. I do hope we can have another QSO in the future and a S2S.

I’ll be listening out for you on Sat morning if you are about.



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What the app does not account for is when the is an area adjacent to the summit that is in the acceptable elevation range, but separated from the AZ “island” around the summit by a dip exceeding 25m.

(Questions of elevation accuracy - both of the user’s device and, hopefully to a lesser extent, of the SOTA database itself, also come into play, but that’s another issue.)

Ben’s not the first to get caught out by this and, as others have said, respect to him for getting out again to make it good.

It’s not a trivial rule to understand and the best I can offer is my explanation here:

My advice to activators is:

  • Use your national mapping (often linked from the summit pages) in preference to other online map sources
  • Look for the contour around the summit no more than 25m below it.

Ben, I don’t think you said for sure if you’d been valid for TP3319 on your original activation for the WAB trig point collectors?

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Hi Simon,

Thank you very much for the AZ explanation, this helps me a lot! As for the WAB, I was attached directly to the trig point.

Many thanks again!



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I think you’re spot on there Simon and I think that it is important that activators don’t solely relay in this app to work out whether or not they’re in the activation zone. I always think that it is a good idea to read proper maps (ideally OS 1 to 25,000 or whatever the equivalent to this is if not in Great Britain) to work out whether or not you’re in the activation zone. Maybe something should be mentioned in the SOTA Website advising not to solely rely on this app and read some proper maps as well.

Jimmy M0HGY