Eventually the flicker noise of most amplifiers (apart from chopper
stabilised and related amplifiers) will exceed the noise of a resistor.
The internal zener noise will in most cases be much larger than
amplifier noise.
The output noise (due to the filter components) of an RC low pass filter
is SQRT(kT/C) where C is the filter capacitance.
For C ~ 1uF the noise is ~3.7 nV rms.
Such noise will add about 3.7E-17 additional FM noise to an HP10811A if
applied directly to the EFC input.
This additional noise several orders of magnitude less than the effect
of other noise sources, so the filter noise is unlikely to be a
significant issue.
However the noise due to the resistor used to add a zero to the filter
response is not filtered by the loop filter capacitor.
Only the low pass filter at the amplifier output and that within the EFC
circuit affects this.
Bob Camp wrote:
Hi
Back when the Z3801 was new, some GPS's would let you pick a specific geoid
model to use for altitude. Apparently it's a receiver side choice of what
model to use.
Bob
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of John Green
Sent: Thursday, January 14, 2010 4:36 PM
To: [email protected]
Subject: Re: [time-nuts] Tbolt altitude error
I had a Tbolt and a Z3801 both fed from the same antenna and they indicated
26 meters differenence in altitude. The 3801 seemed closer to right. If
geoid error were the cause, it seems that both would indicate about the
same.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
