[ntp:questions] Questions about joining pool.ntp.org

Terje Mathisen "terje.mathisen at tmsw.no" at ntp.org
Mon Aug 29 09:16:11 UTC 2011


David Woolley wrote:
> John Hasler wrote:
>
>> Shipping products lacking adequate filtering for adjacent band
>> interference just because those bands are not presently in use is just
>> plain bad engineering.
>
> The new adjacent channel signal could be arbitrarily strong. You have to
> make some assumptions,

Those adjacent bands have been reserved for sat signals, which means 
_very_ low power levels near an earth-based receiver.

With a fancy hack of the FCC system, a US company got a waiver to use 
the same band for 40K earth-based transmitters, each with KW-level 
output power.

The result would be an adjacent signal 5-6(?) orders of magnitude 
stronger than any gps sat signal, making an an effective flat-phase 
filter nearly impossible, at least at a consumer-grade cost figure.

There's no way it will be accepted though, the US simply can't live with 
a GPS system that works everywhere in the world, except in the US.

Terje
-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"




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