[time-nuts] Re: What GNSS module to buy for a good time reference?

[Lux, Jim]

On 6/21/23 7:37 AM, John Ackermann N8UR via time-nuts wrote:
> The F10T looks interesting, but from the datasheet it is missing a few 
> maybe important features compared to the ZED-F9T:
>
> -- L1/L5 bands only (no L2 option)


I'm not sure no L2 is such a big deal - going forward, people are 
pushing to L5. It's better protected spectrum management (adjacent user) 
wise, it has 3dB more power than L1, and longer spreading codes.   The 
only hiccup is that it's only live on 17-18 satellites, 24 by 2025.  L2 
has *less* power than L1, but the longer codes for L2C should make up 
for that.

A question would be whether a L1, L2 receiver uses the L2C, or whether 
they are just doing phase retrieval on the L2 unmodulated carrier (older 
satellites). Or some sort of codeless processing.

There's also a somewhat wider spread between L1 and L5, so in theory, 
you could do better ionospheric corrections.

L1 - 1575.42

L2c - 1227.6

L5 - 1176.45