Hamming it Up

I just received my amateur radio callsign and licence!

Ham radio licence

Ham radio licence, slightly redacted

There is a fixed amount of radio spectrum that is allocated to different purposes in different countries. Certain “bands” have been allocated to amateur radio enthusiasts, or “hams”, to experiment and research new radio technology and create emergency disaster communication links. There are several radio-to-email services for boaters but it requires a radio licence.

In Canada, there are two multiple-choice tests: Basic with 100 questions and Advanced with 50, and both require 70% to pass. In addition, you can complete a morse code test, creating 4 types of certification: Basic, Basic with Morse, Basic with Honours, and Advanced.

In Canada, the Basic certification provides access only to VHF and UHF bands, while the other certifications permit access to HF. VHF and UHF are line-of-sight communication and you cannot usually talk much further than tens of kilometers (there are repeater networks to increase your range, where an automated base station relays communications. Vancouver Island even has a sophisticated “trunk” to relay messages over 400 km!).

Vancouver Island Trunk Network

After a crash-course in studying manuals from RAC I wrote both tests (no Morse code for me). I didn’t pass the Advanced, but my high Basic mark permits me the Honours certification. I now have access to the HF band! This is the truly interesting and complex part of radio as it allows worldwide communication if conditions are just right. You can talk several thousand kilometers with the power of a flashlight!

Since getting my licence I strung up some speaker wire into a tree and sent an email 60 km.  There is much more to this world of radio, and I will post more details as I learn.

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The Onderdonk

What a great name for a boat! I stumbled upon the Preece and Onderdonk equations when learning about limits of electrical wires.

I’ve been designing the electrical system for our boat. Currently, we have a solar panel (60W), a lead acid battery (100 Ah), and a handful of navigation and cabin lights. We only use 12V devices on board and don’t have an engine, alternator, or shore power connection.

The battery box: charge controller, battery, fuses, switches all in one place.

The battery box: charge controller, battery, fuses, switches all in one place.

We will be increasing the capacity for new luxuries of a windlass, a laptop, SSB radio, cordless power tools, USB ports, VHF radio, etc.

My method for designing the system:

  1. Loads. Calculate your typical loads (amps) and duration (amp-hours) for a typical day. Not every device on the boat will be on at the same time!
  2. Battery capacity. Aim to have battery capacity of 3x that typical load, so that the batteries are only discharged by 30% per cycle.
  3. Solar panels. Estimate typical solar panel output on a “good” day, and on a typical day.
  4. Charge control. Without a charge controller, solar panels will overcharge and destroy a battery. The controller must be be rated for the charging current.
  5. Wiring. All wire will reduce the voltage and lose a percentage of power. Size the wiring to minimize voltage drop and power loss.
  6. Safety and distribution. Add sufficient fuses and circuit breakers, and an ability to switch circuits on and off.
  7. Iterate. Go back through these steps and make sure it still makes sense. Pricing provides the final decision.

What has been decided?

  • The batteries will be 12V AGM or gel with 160 to 220 Amp-hours capacity.
  • 400 W of solar panels which I estimate to provide 60 Ah/day to the batteries. The panels provide a peak 24 amps.
  • The charge controller will be a Flexcharge NC25A and is capable of handling AGM or gel batteries at a charging current of 25 amps.
  • The wiring will be 2/4 AWG for the main distribution, 10 AWG for the solar panels, and 14 AWG for general instruments.

More updates as we begin ordering and installing the parts!

Composite LPG Cylinder woes

After decades of a Primus kerosene stove, Piggy was upgraded with a propane (LPG) stove and oven. Propane requires pressure vessels and these must follow strict safety tests and lifespan. The typical barbecue tank is steel; the salty air around a boat created a market for aluminum tanks which are lighter, won’t leave rust marks and will have a longer lifespan. Unfortunately these are 5- 10 times the price!

A third alternative, composite tanks made of fibreglass, have entered the market. They are priced around 2 to 3 times more than steel, are half the weight, will never corrode, and are translucent to see the propane level.

I have found three manufacturers: Hexagon Ragasco in Norway, Lite Manufacturing in Tennessee, and Trident Marine in Pennsylvania. We purchased a Lite tank, which has now been recalled and the company has become insolvent. Oh no!

Is it really so bad? Can we risk using the tank? The company did not report the following issues:

  • 3 ruptures resulting in injuries or damage to property.
  • 19 cylinders returned due to sidewall and bottom leaks.
  • Selling 1000 cylinders to Dominican Republic after a suspension notice was issued for that model of cylinder. One cylinder failed during transport and injured occupants in the vehicle.
  • Selling prototype cylinders of with false safety certification.

In addition:

  • Did not proof test each cylinder at a high enough pressure (441 psi vs. 480 psi).
  • Did not randomly select cylinders for fatigue/burst tests, instead chose the first from each production batch. Did not follow up with burst tests after failures during production.
  • Insufficient maintenance procedures for the grinder/fitter.
  • Inoperable alarm system for running out of catalyst when gluing the two cylinder halves.

When the PHMSA shut down the company it found 4.6% of the inventory had leaks, and the previous 4 years had an increasing trend of failures!

failures

Cylinder failures at Lite Manufacturing during proof testing (1.5x pressure during service) and leak testing.

Fortunately, it appears similar-sized tanks have just entered the Canadian-certified market. I’m planning to use Viking cylinders from Norway.