[TowerTalk] How accurate are iPhone Compass apps?

[K8RI]

On 1/4/2012 1:15 PM, Jack Brindle wrote:
> More than that, as I learned in designing mobile and portable
> commercial equipment, cars and airplanes have pretty much infinite
> power available, while the battery-powered iPhone does not. Radios
> (especially GPS devices) require lots of power, draining the battery
> fairly quickly. You can manage a modern cell phone radio to limit
> power drain (thus extending battery life), but a GPS receiver needs to
> be on all the time to maintain its status. The hall effect sensors
> provide an excellent alternative to this, keeping the power drain low
> so you can go several days without recharging.
>
> By the way, TPA went through a runway renumbering because of mag north
yah, the magnetic pole has accelerated to about 20 miles per year.

> change this past year. The real story appears to be that they actually
> misnumbered at least one of the runways, but at least now they seem to
> have it right.
>
> 73!
>
> Jack B, W6FB
>