Being at +93ishm _does_ clear the +70m hill (90m actual) but not at an angle that should let me see the 0m points - but I do.<\/p>
So.<\/p>
Bouncy signals? Bad maths? Weird RF-over-angle behaviours? (Same kind of thing gets you picket fencing)<\/p>
I dunno.<\/p>
hm<\/p>
I don't think I'm fucking up my maths but am I?<\/p>
Or is this \"don't mix google maps and open maps it only leads to pain\"?<\/p>
#gmrs<\/a> #AmateurRadio<\/a><\/p>","generator":{"id":"tag:gnusocial.jp,2026-10-14:notice-source:ActivityPub","objectType":"application","status_net":{"source_code":"ActivityPub"}},"id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388565771194810","object":{"id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388565771194810","objectType":"note","content":" Being at +93ishm _does_ clear the +70m hill (90m actual) but not at an angle that should let me see the 0m points - but I do.<\/p> So.<\/p> Bouncy signals? Bad maths? Weird RF-over-angle behaviours? (Same kind of thing gets you picket fencing)<\/p> I dunno.<\/p> hm<\/p> I don't think I'm fucking up my maths but am I?<\/p> Or is this \"don't mix google maps and open maps it only leads to pain\"?<\/p> #gmrs<\/a> #AmateurRadio<\/a><\/p>","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388565771194810","status_net":{"notice_id":null},"inReplyTo":{"objectType":"note","id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388539174321890","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388539174321890"},"tags":[{"objectType":"http:\/\/activityschema.org\/object\/hashtag","displayName":"amateurradio"}]},"to":[{"objectType":"http:\/\/activitystrea.ms\/schema\/1.0\/collection","id":"http:\/\/activityschema.org\/collection\/public"}],"status_net":{"conversation":"tag:gnusocial.jp,2026-04-12:objectType=thread:nonce=e2c828dc0ac9274f","notice_info":{"local_id":"12437143","source":"ActivityPub"}},"published":"2026-04-12T00:34:59+00:00","provider":{"objectType":"service","displayName":"GNU social JP","url":"https:\/\/gnusocial.jp\/"},"verb":"post","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388565771194810"},{"actor":{"id":"https:\/\/ioc.exchange\/users\/flyingsaceur","displayName":"AN\/CRM-114","status_net":{"avatarLinks":[{"url":"https:\/\/gnusocial.jp\/avatar\/162315-original-tmp20260228030735.webp","rel":"avatar","type":"image\/webp","width":400,"height":400},{"url":"https:\/\/gnusocial.jp\/avatar\/162315-96-20260302104359.webp","rel":"avatar","type":"image\/webp","width":96,"height":96},{"url":"https:\/\/gnusocial.jp\/avatar\/162315-48-20260228231757.webp","rel":"avatar","type":"image\/webp","width":48,"height":48},{"url":"https:\/\/gnusocial.jp\/avatar\/162315-24-20260302104359.webp","rel":"avatar","type":"image\/webp","width":24,"height":24}],"profile_info":{"local_id":"162315"}},"image":{"url":"https:\/\/gnusocial.jp\/avatar\/162315-96-20260302104359.webp","rel":"avatar","type":"image\/webp","width":96,"height":96},"objectType":"person","summary":"\u201cI\u2019ve done\u2026 questionable things.\u201dSuburban crank monitoring the airwaves from the High Castle. Deep space janitor. Miniboss. Agile bagman. Python daily driver and hater. Secret Perl Sicko. Standard ML dilettanteACAB, ACARS, LCARS. Welcome to AVALANCHE\u201cFirst we shape our tools, then our tools shape us\u201d \u2014Marshall McLuhanhe \/ him \/ sir","url":"https:\/\/ioc.exchange\/@flyingsaceur","portablecontacts_net":{"preferredUsername":"flyingsaceur","displayName":"AN\/CRM-114","note":"\u201cI\u2019ve done\u2026 questionable things.\u201dSuburban crank monitoring the airwaves from the High Castle. Deep space janitor. Miniboss. Agile bagman. Python daily driver and hater. Secret Perl Sicko. Standard ML dilettanteACAB, ACARS, LCARS. Welcome to AVALANCHE\u201cFirst we shape our tools, then our tools shape us\u201d \u2014Marshall McLuhanhe \/ him \/ sir"}},"content":" @moira<\/a> ACHIEVEMENT UNLOCKED: knife-edge diffraction<\/p> https:\/\/www.raymaps.com\/index.php\/knife-edge-diffraction-model\/<\/a><\/p>","generator":{"id":"tag:gnusocial.jp,2026-10-14:notice-source:ActivityPub","objectType":"application","status_net":{"source_code":"ActivityPub"}},"id":"https:\/\/ioc.exchange\/users\/flyingsaceur\/statuses\/116388860072033749","object":{"id":"https:\/\/ioc.exchange\/users\/flyingsaceur\/statuses\/116388860072033749","objectType":"note","content":" @moira<\/a> ACHIEVEMENT UNLOCKED: knife-edge diffraction<\/p> https:\/\/www.raymaps.com\/index.php\/knife-edge-diffraction-model\/<\/a><\/p>","url":"https:\/\/ioc.exchange\/@flyingsaceur\/116388860072033749","status_net":{"notice_id":null},"inReplyTo":{"objectType":"note","id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388565771194810","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388565771194810"}},"to":[{"objectType":"http:\/\/activitystrea.ms\/schema\/1.0\/person","id":"https:\/\/mastodon.murkworks.net\/users\/moira"},{"objectType":"http:\/\/activitystrea.ms\/schema\/1.0\/collection","id":"http:\/\/activityschema.org\/collection\/public"}],"status_net":{"conversation":"tag:gnusocial.jp,2026-04-12:objectType=thread:nonce=e2c828dc0ac9274f","notice_info":{"local_id":"12437144","source":"ActivityPub"}},"published":"2026-04-12T00:34:58+00:00","provider":{"objectType":"service","displayName":"GNU social JP","url":"https:\/\/gnusocial.jp\/"},"verb":"post","url":"https:\/\/ioc.exchange\/@flyingsaceur\/116388860072033749"},{"actor":{"id":"https:\/\/mastodon.murkworks.net\/users\/moira","displayName":"Solarbird :flag_cascadia:","status_net":{"avatarLinks":[{"url":"https:\/\/gnusocial.jp\/avatar\/68099-original-tmp20230622190621.webp","rel":"avatar","type":"image\/webp","width":400,"height":400},{"url":"https:\/\/gnusocial.jp\/avatar\/68099-96-20230719121623.webp","rel":"avatar","type":"image\/webp","width":96,"height":96},{"url":"https:\/\/gnusocial.jp\/avatar\/68099-48-20230719121623.webp","rel":"avatar","type":"image\/webp","width":48,"height":48},{"url":"https:\/\/gnusocial.jp\/avatar\/68099-24-20230719121623.webp","rel":"avatar","type":"image\/webp","width":24,"height":24}],"profile_info":{"local_id":"68099"}},"image":{"url":"https:\/\/gnusocial.jp\/avatar\/68099-96-20230719121623.webp","rel":"avatar","type":"image\/webp","width":96,"height":96},"objectType":"person","summary":"Bluesky user? Read: http:\/\/mastodon.murkworks.net\/@moira\/113647708264029959She\/her ex-software dev; writer of words for money, fun, and survival both here and at my blog; maker of bike maps, printables, radio noise (KK7ZLU\/WSLT671), baked goods, & random projects.Republicans have tried to kill off me & mine my whole life; if you hate "Dems" and "libs" more than actual fash, DNI & GFY.Support me or my Mastodon instance: http:\/\/patreon.com\/solarbird","url":"https:\/\/mastodon.murkworks.net\/@moira","portablecontacts_net":{"preferredUsername":"moira","displayName":"Solarbird :flag_cascadia:","note":"Bluesky user? Read: http:\/\/mastodon.murkworks.net\/@moira\/113647708264029959She\/her ex-software dev; writer of words for money, fun, and survival both here and at my blog; maker of bike maps, printables, radio noise (KK7ZLU\/WSLT671), baked goods, & random projects.Republicans have tried to kill off me & mine my whole life; if you hate "Dems" and "libs" more than actual fash, DNI & GFY.Support me or my Mastodon instance: http:\/\/patreon.com\/solarbird"}},"content":" @flyingsaceur<\/a> That's (part of) the thing that causes picket fencing, innit? Or am I conflating things that I shouldn't be conflating?<\/p> anyway that diagramme is helpful thanks, it's a bigger angle add than i expected!<\/p>","generator":{"id":"tag:gnusocial.jp,2026-10-14:notice-source:ActivityPub","objectType":"application","status_net":{"source_code":"ActivityPub"}},"id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388876784594489","object":{"id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388876784594489","objectType":"note","content":" @flyingsaceur<\/a> That's (part of) the thing that causes picket fencing, innit? Or am I conflating things that I shouldn't be conflating?<\/p> anyway that diagramme is helpful thanks, it's a bigger angle add than i expected!<\/p>","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388876784594489","status_net":{"notice_id":null},"inReplyTo":{"objectType":"note","id":"https:\/\/ioc.exchange\/users\/flyingsaceur\/statuses\/116388860072033749","url":"https:\/\/ioc.exchange\/@flyingsaceur\/116388860072033749"}},"to":[{"objectType":"http:\/\/activitystrea.ms\/schema\/1.0\/person","id":"https:\/\/ioc.exchange\/users\/flyingsaceur"},{"objectType":"http:\/\/activitystrea.ms\/schema\/1.0\/collection","id":"http:\/\/activityschema.org\/collection\/public"}],"status_net":{"conversation":"tag:gnusocial.jp,2026-04-12:objectType=thread:nonce=e2c828dc0ac9274f","notice_info":{"local_id":"12437145","source":"ActivityPub"}},"published":"2026-04-12T00:34:57+00:00","provider":{"objectType":"service","displayName":"GNU social JP","url":"https:\/\/gnusocial.jp\/"},"verb":"post","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388876784594489"},{"actor":{"id":"https:\/\/mastodon.murkworks.net\/users\/moira","displayName":"Solarbird :flag_cascadia:","status_net":{"avatarLinks":[{"url":"https:\/\/gnusocial.jp\/avatar\/68099-original-tmp20230622190621.webp","rel":"avatar","type":"image\/webp","width":400,"height":400},{"url":"https:\/\/gnusocial.jp\/avatar\/68099-96-20230719121623.webp","rel":"avatar","type":"image\/webp","width":96,"height":96},{"url":"https:\/\/gnusocial.jp\/avatar\/68099-48-20230719121623.webp","rel":"avatar","type":"image\/webp","width":48,"height":48},{"url":"https:\/\/gnusocial.jp\/avatar\/68099-24-20230719121623.webp","rel":"avatar","type":"image\/webp","width":24,"height":24}],"profile_info":{"local_id":"68099"}},"image":{"url":"https:\/\/gnusocial.jp\/avatar\/68099-96-20230719121623.webp","rel":"avatar","type":"image\/webp","width":96,"height":96},"objectType":"person","summary":"Bluesky user? Read: http:\/\/mastodon.murkworks.net\/@moira\/113647708264029959She\/her ex-software dev; writer of words for money, fun, and survival both here and at my blog; maker of bike maps, printables, radio noise (KK7ZLU\/WSLT671), baked goods, & random projects.Republicans have tried to kill off me & mine my whole life; if you hate "Dems" and "libs" more than actual fash, DNI & GFY.Support me or my Mastodon instance: http:\/\/patreon.com\/solarbird","url":"https:\/\/mastodon.murkworks.net\/@moira","portablecontacts_net":{"preferredUsername":"moira","displayName":"Solarbird :flag_cascadia:","note":"Bluesky user? Read: http:\/\/mastodon.murkworks.net\/@moira\/113647708264029959She\/her ex-software dev; writer of words for money, fun, and survival both here and at my blog; maker of bike maps, printables, radio noise (KK7ZLU\/WSLT671), baked goods, & random projects.Republicans have tried to kill off me & mine my whole life; if you hate "Dems" and "libs" more than actual fash, DNI & GFY.Support me or my Mastodon instance: http:\/\/patreon.com\/solarbird"}},"content":" okay so let's think this out<\/p> I have a UHF antenna at a not well known height pinging a location gmaps says is 1084 meters away (line of sight).<\/p> We'll call the altitude of that location\u00a00m to simplify maths. Openmaps has it on the low side of a 20m line. That matters to get actual altitude at the end; at most, it's another 2-3m down probably?<\/p> At 850m (straight-line) from my 0m location, a signal clears a +70m hill on its way to either end.<\/p> So start at 0m and create a right triangle with the signal path, and 70\/850 should be the tan() of the angle from the 0m point. Therefore 70\/850 = X\/1084, and doing the maths gets you X = 90m.<\/p> 90+20=110m, ish.<\/p> But my best direct estimate from the same topo maps is 93-95m.<\/p> #gmrs<\/a> #AmateurRadio<\/a><\/p>","generator":{"id":"tag:gnusocial.jp,2026-10-14:notice-source:ActivityPub","objectType":"application","status_net":{"source_code":"ActivityPub"}},"id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388539174321890","object":{"id":"https:\/\/mastodon.murkworks.net\/users\/moira\/statuses\/116388539174321890","objectType":"note","content":" okay so let's think this out<\/p> I have a UHF antenna at a not well known height pinging a location gmaps says is 1084 meters away (line of sight).<\/p> We'll call the altitude of that location\u00a00m to simplify maths. Openmaps has it on the low side of a 20m line. That matters to get actual altitude at the end; at most, it's another 2-3m down probably?<\/p> At 850m (straight-line) from my 0m location, a signal clears a +70m hill on its way to either end.<\/p> So start at 0m and create a right triangle with the signal path, and 70\/850 should be the tan() of the angle from the 0m point. Therefore 70\/850 = X\/1084, and doing the maths gets you X = 90m.<\/p> 90+20=110m, ish.<\/p> But my best direct estimate from the same topo maps is 93-95m.<\/p> #gmrs<\/a> #AmateurRadio<\/a><\/p>","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388539174321890","status_net":{"notice_id":null},"tags":[{"objectType":"http:\/\/activityschema.org\/object\/hashtag","displayName":"amateurradio"}]},"to":[{"objectType":"http:\/\/activitystrea.ms\/schema\/1.0\/collection","id":"http:\/\/activityschema.org\/collection\/public"}],"status_net":{"conversation":"tag:gnusocial.jp,2026-04-12:objectType=thread:nonce=e2c828dc0ac9274f","notice_info":{"local_id":"12437132","source":"ActivityPub"}},"published":"2026-04-12T00:33:38+00:00","provider":{"objectType":"service","displayName":"GNU social JP","url":"https:\/\/gnusocial.jp\/"},"verb":"post","url":"https:\/\/mastodon.murkworks.net\/@moira\/116388539174321890"}],"links":[{"url":"https:\/\/gnusocial.jp\/conversation\/6314335","rel":"alternate","type":"text\/html"}]}