Oh Dear .... the do-gooders having a field day today !!
OK ... I have had my P3S and P3P at near 500m ... but first you must have the AC at a horizontal distance from you ... 100m is enough ... then make sure centre antenna (5.8) is angled so its parallel to the AC ... NOT tip pointing at it. Hold the Controller so top is facing at AC all times to get max from the 2.4 antenna inside.
Best area to do it is out in the country well away from everything and with clear space. This also means that its unlikely to have any other craft in the sky at such level apart from another RC hobbyist ! Aircraft that low are either in trouble or crop sprayers !!
Just go straight up then ... you will NOT get 500 ... both my P3S and P3P bounced around the 470 - 480m mark refusing to actually hit the magic 500m.
OK ... there is another factor that can affect altitude test ..... proximity to NFZ or Restricted Airspace. FW has embedded into it altitude restrictors that prevent you getting higher than the FW has internally programmed. Here is a video showng my P3P having its altitude reduced as it flies closer to the centre of the NFZ ... (airport management are close friends of mine and I am in contact with them)...
Here's an early test that gets to 470m ..... the video is actually when I was showing a new P3S owner some of the items he should know ... such as LEFT STICK down etc. The P3S of mine here has the Argtek antenna system which does increase its capability as you see in the distance part ...
Nigel