[time-nuts] Accuracy/drift of Garmin GPS 16 HVS 1 PPS output under invalid fix conditions...

[Steve Olney]

Hi,

I see Tom has recently put up results of measurements of some Garmin GPS 
receivers.

Thanks Tom.

While the measured out-of-lock timing performance of the 16's PPS is 
extremely poor by time-nuts standard - it is adequate for my current 
purposes - however...

What is more of a concern is the confirmation of my own experience 
w.r.t. sensitivity.  I have the old 16 model (not 16x) and was surprised 
to observe that it required being on the roof in the clear to prevent 
loss-of-lock.  Comparing this to a cheapey eBay dongle receiver which 
maintains lock even when inside on a window sill was a surprise.  The 
dongle needed to be 1 m inside the window to drop lock - impressive 
given the window is under a verandah with only a view of the sky through 
trees to the north from zero to 30 degrees elevation.

Depending on how you read the specifications the dongle is 27 dB more 
sensitive than the 16 - which accounts for the poor sensitivity I have 
observed with the 16.

Ah well - I bought 4 16s in a state of ignorance...

Caveat emptor...

Cheers

Steve Olney

HawkRAO