This may be a futile battle: Your receiver seems to be optimized for (car) navigation. It may not even be capable to serve as a precise time source.
What you could try:
- Disable all PPS processing on the client. Even if the receiver should "emulate" this signal over USB, it won't be reliable.
- Limit message types on the receiver to only the NMEA types required for timing. This will "free up" bandwidth and maybe enable the receiver to report more often, giving a more plausible signal to the client.
- Increase comm speed from 4800 to something higher on the receiver. Same as before, this may enable the receiver to give more regular reports.
- Make sure the receiver has a good signal. If it looses the signal every now and then, the client will tend to view it as unreliable.
... but again, consider whether it's worth your time: You won't get precise timing out of this device anyway, you might be better off using internet time servers in the first place.
What you could try:
- Disable all PPS processing on the client. Even if the receiver should "emulate" this signal over USB, it won't be reliable.
- Limit message types on the receiver to only the NMEA types required for timing. This will "free up" bandwidth and maybe enable the receiver to report more often, giving a more plausible signal to the client.
- Increase comm speed from 4800 to something higher on the receiver. Same as before, this may enable the receiver to give more regular reports.
- Make sure the receiver has a good signal. If it looses the signal every now and then, the client will tend to view it as unreliable.
... but again, consider whether it's worth your time: You won't get precise timing out of this device anyway, you might be better off using internet time servers in the first place.