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ClearNav Service

Please Contact ClearNav Instruments prior to shipping any ClearNav products for repair.

ClearNav Inc.
2668 Husted Rd
Williams, CA  95987-5105 USA

FAX: 530-473-5315
Phone: 530-473-5600


Servicing of Legacy Cambridge Aero Instruments

Please Contact Gary Kammerer Prior to shipping any Cambridge Aero products for service.

Gary Kammerer - Independent Contractor
Cambridge Service/Support
144 Daltons Rd
Waterbury, VT 05676

Gary Kammerer - Customer Service


Cambridge Model 10/20/25 and 302 Garmin UTC Repair Pricing

Model 10/20/25 Repair --- Repair includes opening the receiver, replacing the Garmin internal 3v lithium re-chargeable battery with a new one, re-setting the UTC date and performing a barograph calibration. A label will be placed on the unit to remind you to power the unit overnight during lengthy periods of non-use (4 or more months) ... this will recharge the Garmin battery so the UTC date does not fail. Cost: $175.00

Model 302 Repair---The Garmin receiver will be replaced with a new Garmin receiver that does not have the date issue. The repair will include a barograph calibration and a 1 year warranty. Cost: $350.00 + S/H.

Cambridge Legacy Service, Provided by Gary Kammerer - Independent Contractor

Cambridge Logo

300 Series Instruments

GPS-NAV™ Recorder

GPS-NAV™ Display

L-NAV™ Glide Computer

S-NAV™ Glide Computer

CAVII™ Variometer

CAI 302 Repair Policy

Gary Kammerer has moved to a fixed price service policy.  For $350* we will:

  • Repair almost any 302**
  • Clean and test and inspect as appropriate, connectors, boards and components
  • Calibrate the altitude pressure transducer and provide a new calibration certificate
  • Issue a full one-year warranty to cover the entire instrument, not merely the repaired item(s)

*There will be a minimum charge of $125.00 if no defects are found and the unit is determined to be functioning perfectly.
**Almost any – we reserve the right to return at no cost any instrument which we judge not repairable – for example if you drove the trailer over it or filled it with water in a water landing.

Standard Services and Rates

Service department rate for all repairs is $90 per hour, with a minimum $75 charge for any unit accepted for test and evaluation.

The standard rate for calibration of your GPS-NAV, L-NAV or S-NAV is $75. Calibration of your GPS-NAV Datalogger will include a Barograph Calibration Certificate in approved IGC format. Standard calibration turnaround for a pre-authorized and paid calibration is five business days or less. RUSH service (two day or better turnaround) is available for an additional fee of $50. If additional service is required at the time of calibration, total time and materials will be billed at the $90/hour rate, including the time spent on calibration.

Gary is pleased to offer firmware upgrades to the most current version available for GPS-NAV Dataloggers and L-NAV/S-NAV Glide Computers. Firmware upgrades are offered at a flat rate of $75.

Note that while Gary is well stocked with components for the above products, there may be some repairs we are unable to perform because of part obsolescence. In this event, the product will be returned to you in the condition received and you will be billed for our test and evaluation time (minimum $75).

How to Return a Cambridge Aero Instrument

All repair and calibration services will be performed under the supervision of Gary Kammerer. Gary is a former Cambridge Aero Instruments employee and has years of experience providing service and support to the above instruments. Contact Gary by e-mail or phone to discuss your problem and service procedures. Gary is available to trouble-shoot your legacy Cambridge product Monday to Friday from 9 to 5 EST at 802-882-8530. Gary can also be reached by email at

Please note that ClearNav Instruments is not able to provide general technical support relating to use of Cambridge Aero Instruments. For manuals and reference materials, you can visit Dickie Feakes’ Bicaster Aviation site in the UK. For paid phone and web-conferenced technical support, you may also contact Paul Remde at Cumulus Soaring.

You can also view in-depth demos of the GPS-NAV and L-NAV on the Cumulus Soaring download page:

GPS-NAV Demo/Training Files L-NAV Demo/Training Files

These demos can provide an excellent introduction if you have purchased one of these products from another pilot.

Cambridge Aero Instruments, the Cambridge Logo, GPS-NAV, L-NAV, S-NAV and CAV-II are licensed trademarks of R-Track Technologies, Inc., Memphis, TN.

Copyright©  ClearNav Inc.
2668 Husted Road Williams, CA  95987  USA
Phone: 530-473-5600