Freq Error with GNSS

Geoff AB6BT

What frequency error are folks seeing on their 8600?

The GPS tab shows 30 sats visible and 11 tracked.

The Freq Error is currently -212.1 ppb.

GNSS is selected as the 10 MHz Reference and shows Locked.

Thanks.

Trucker

My 8600M is showing basically the same thing. I have noticed that the number of satellites vary ( they are not stationary) as does the frequency error. I figure 268 ppb error rate is pretty good.

James

WD5GWY

Mike-VA3MW

-212 ppb is pretty small.

Trucker

I have been doing some reading about GNSS receivers. Interesting stuff. Some are capable of frequency errors in Parts Per Trillion! Hard to imagine what needs that kind of accuracy. Maybe, the Star Trek transporter!

James

WD5GWY

Geoff AB6BT

Thanks for all the feedback. I realize the ppb number is relatively small and I had actually used the same on-line calculator that Mike posted.

I was just interested in seeing other's experience.

km9r.mike

I was just interested in seeing other's experience……………….

Some additional data for you Geoff. I even hooked up the GNSS antenna for the first time to get you this data after about 5 months since receiving my 8600. Call me old school but I see no need to know the exact lat/long of my rig. I know where it is located and that is sufficient for me. Regardless here is the data.

From the "radio setup GPS tab"

19 sats vis

3 tracked

status locked (solid blue light)

freq error is dynamic and varies from 269 ppb to 271 ppb so call it 270.0 ppb

From the "radio setup RX tab"

CAl freq 15 Mhz

tcxo locked

pressing the start button produced an initial offset of 280.0 ppb

Cal freq 15 Mhz

gnss locked

pressing the start button produced an offset of 334.0 ppb ( I returned to GPS tab and that was still showing an offset of approximately 270.0 ppb )

finally with Cal freq 15 Mhz

and back to tcxo locked

pressing the start button a third time showed offset was now 334 ppb vice the previous 280.0 ppb.

It is interesting that the initial result I got by running the freq calibration test feature in the "RX" tab with tcxo locked was closer to the dynamic data produced in "GPS" tab

I hope this data helps you.

Mike-VA3MW

That does sound a little light. It should be 10^-9.

Where do you have your GPS antenna mounted? How much of the sky does it see?