[time-nuts] Garmin 18x, new firmware Ver 3.60, NOT recommended for Time Nuts!

[Kiwi Geoff]

David Taylor wrote:
> The new Garmin 3.70 firmware which corrects the problem

I agree, the new version 3.70 at last does not suffer from excessive
NMEA latency.

It looks like our messages to Garmin finally got through David.

Last night I did a 12 Hr test of the NMEA latency with the new 3.70
version firmware for the Garmin 18x.

I measured the time of the "START" character ($) of the $GPRMC
sentence and  the "LAST" 0x10 (Linefeed) character, relative to the
leading transition of the 1PPS, GPS 18x set to 4800 Baud.

Times are in "milliseconds" wrt previous 1PPS

Version 3.20 firmware for Garmin 18x     *** Previous GOOD version ***
START Min =  370
START Avg =  433  (N = 7200)
START Max =  518
LAST Min =  519
LAST Avg =  582    (N = 7200)
LAST Max =  667

Version 3.70 firmware for Garmin 18x   *** NEW June 2011 ***
START Min =  333
START Avg =  413  (N = 43,402)
START Max =  491
LAST Min =  482
LAST Avg =  562    (N = 43,402)
LAST Max =  640

So no more 1 second slow !

Regards, Geoff , Christchurch, New Zealand.