GMR Retrotrip3 is a simple evolution of the ever-popular Retrotrip2
and has all the same features of accurate one-in-a-thousand
pushdigit calibration and clicking electromechanical readouts
which has made the Retrotrip2 eligible for historic type rallies
throughout the world. Where the Retrotrip3 differs is that
it contains two completely separate and independant tripmeters
in the same box. One tripmeter drives the normal two counters
on the top row of the box. A switch allows one of these two
counters to be disconnected to hold a reading for 'whatever'
purpose. A second tripmeter with its' own calibration switches
drives a third readout on the lower row. Both tripmeters are
fed from the same single sensor fitted to either the speedometer
cable or road wheel. All counters can be zeroed independently.
1 (C1) for the top two counters is as normal and should be
done accurately. Zero the counters and set the calibration
1 digits to 100 and drive a measured kilometre (or mile if
working in miles and miles per hour). Enter this figure onto
the calibration 1 pushdigits. A more accurate figure can be
obtained by driving a measured two kilometres and dividing
the readouts by two. The tripmeter will now indicate hundredths
of a kilometre or mile depending on the distance travelled.
If you have a second tripmeter (and the GMR Retrotrip3 has
two independent tripmeters) you can achieve an indication
of AVERAGE SPEED, by calibrating the second tripmeter to a
different figure as derived from the Bath Formula supplied
with each GMR Retrotrip3.
GMR Retrotrip3 is wired as follows: The black cable is the
power feed and contains a brown wire which is connected to
+12volts. The Green/yellow is connected to the -12volts. Whichever
of these two wire is the 'live' it should be fitted with a
fuse of not more than 2 amps. Wiring must be taken directly
from the vehicle's battery terminals and not from the chassis
or existing vehicle wiring. Cars which have a 6 volt or 12
volt dynamo system (ie not a negatively earthed alternator
type charger) must use the Brantz Power Conditioner. The grey
cable connects to the sensor as indicated on the sheet supplied
with the tripmeter. If using the normal universal speedometer
cable sensor then Brown goes to brown, Blue goes to blue,
and Green/Yellow goes to green. The GMR Retrotrip3 is hand
crafted by a member of the Guild of Master Craftsmen.