The Open Source Cox Amplifier (OSCA™) was designed as a robust alternative to commercially available cox amplifiers with similar features. This product is the full kit including GPS module, silk screened, double sided printed circuit board, all components including 5 core cable, Amphenol ™ standard plug (Fits most NK™ and other common wiring looms), LCD screen, 8 high capacity 2500mA AA size NiMh rechargeable batteries, battery charger, and all tube enclosure fittings. OSCA™’s key features include:

· 5-watt power amplifier (more than ample), and microphone preamplifier

· Very accurate Global Positioning System (GPS) based speed readout

· Stroke rate meter

· Able to show Km/h or MPH or knots. (selectable)

· Audible selectable metronome for rate training

· Distance travelled per stroke readout for maximising efficiency of crew

· Digital volume control – eliminates potential for water ingress, unlike other systems that use a protruding knob.

· Universal standard 5 pin Amphenol ™ plug – connects to NK ™ and many other standard wiring systems

· Large two line backlit LCD display

· Very long battery life with visual and audible low battery alarms. Around 10 hrs **minimum** operating time between charges.

· Compatible with UHF radio input

· Future provision for data storage and retrieval board

· Low cost solution for most schools and clubs

Download the electronic construction manual here

Download the case construction manual here

Download the user manual here

Technical details:

OSCA™ can be used in any coxed 4 or coxed 8 vessel. The open source nature of OSCA™ allows the user to benefit from any software revisions created by the general user community.

OSCA is based on two readily available microprocessors, the Picaxe(TM) 08M and the Picaxe 18X. These processors are programmed using a reasonably easy to understand basic language, and can be programmed with a free programming editor from http://www.rev-ed.co.uk/picaxe/ Upgrading firmware is therefore a simple matter of installing the programming editor software, connecting a serial lead to OSCA, and downloading the firmware update from the internet. Of course, as most schools and clubs don't wish to tinker with the firmware, OSCA comes with a pre programmed microprocessor with the latest firmware, so no programming skills are required.

While brand named cox amplifiers (such as Nielsen-Kellermans (NK™) cox boxes™) can cost AU$800+, care has been taken to ensure that the price of OSCA remains at a competitive kit level price point. This ensures that OSCA can be within the reach of many rowing club budgets, and ensures that more rowers have the advantage of monitoring speed, stroke rate, and other vital statistics as part of their regular training schedule. Utmost care has been taken to make OSCA as easy as possible to obtain and assemble, allowing more rowing clubs around the world, the ability to utilise the benefits of precision equipment.

The marine environment is a harsh one. We all know how much abuse any racing equipment, especially a cox amp, can suffer, even in everyday use. Functionality, ruggedness and reliability have not been compromised by using readily available components in the production of OSCA.

Case Construction:

OSCA is housed in 90mm PVC stormwater tubing. By design, stormwater tubing is cheap, reliable, UV stabilised, strong, and with the correct sealant, completely waterproof. A 100mm to 90mm reducer forms the front of OSCA. A 90mm rear press-on stopper sealed with PVC tubing adhesive ensures that water ingress is eliminated. Once sealed correctly, OSCA does not ever need to be opened again. The high capacity 2500mA Ni-Mh batteries can be recharged over 1000 times, allowing the life of each OSCA to be in the order of 20 years, assuming one charge per week.

Operating time per charge depends on the volume level set, and the frequency of the coxswain’s calls. Typically a minimum of 10 to 15 hours continuous run time is expected between charges. Recharging time is through a trickle charge system, which will fully charge the batteries on an overnight charge.

The face of OSCA is made of three layers. Two layers of which are watertight.
A standard BNC plug with rubber surround is fixed to the top of the face. On the rear, a single waterproof rubber compressed grommet (IP68 rated ) allows the single cable to exit OSCA. This cable is terminated with a 5 pin rubber Amphenol connector, which is completely compatible with most standard racing shell electrical systems, including NK™. All care in designing OSCA has been taken to eliminate water ingress.

The final product, once sealed correctly, should be completely watertight. As there are no user serviceable components inside OSCA, there is no requirement to ever access to the electronics after completion of construction.

This full form kit includes everything required to get you going; a quality solder masked printed circuit board, all onboard components, the case, all switches and connectors, including the standard waterproof Amphenol connector, 8 high capacity 2500mAh batteries, GPS module with internal antenna, battery charger and a detailed step by step instruction booklet.

AU$349.95

Don't want to pick up a soldering iron?

If you are apprehensive about building your cox amplifier kit, I can assemble it for you! Email me with your particular concerns. I can either solder the board, or make the case, or both! Email philippawlowski at hotmail dot com.