Bailing Wire Anemometer

I decided I need something to measure wind speed, so I built this from bailing wire and a Trader Joe's cereal box. (It has not been calibrated yet. I need someone to drive the car.)

Radios

It has been quite a while since Ham Radio has been active around here. Recently, it has received revived interest.
Here are the current crop of radios:

Left to right:
    Kenwood TM-G707 dual band 2M/70cm mobile transceiver
    Kenwood TH-G71 dual band 2M/70cm hand-held transceiver
    Alinco DJ-280T 1.25M (220MHz) hand-held transceiver
    Cobra PR 900 DX FRS (Family Radio Service) two-way radios - aka walkie talkies

These are mostly late 1990's vintage.

There are a couple of local 2 meter repeaters (which I think should be called transponders, but no one else seems to think so) that are fairly active, but so far I have not found any activity on the 440MHz band or 220Mhz.

(It's shocking to realize it has been 5 years since the last post ...)

My Cardboard(s)

Google cardboard is my path to Virtual Reality.


My first attempt is built from a pizza box. The pizza was great - the viewer... not so great.
I used scissors and knives.
I ordered some inexpensive lenses, but don't have them yet. With effort, I can actually perceive the images in 3D without the lenses, albeit very fuzzily.

My second attempt was cut from a clean piece of cardboard from some kind of packing. This time I used an Xacto knife, which made a much cleaner job. I used spray adhesive to glue the printed pattern to the cardboard.
It takes me about an hour to cut out the complete set.

In order to have a really nice Cardboard, we ordered a kit from KnoxLabs.It is complete with lenses, magnets and velcro tabs, but not the NFC chip. It cost $16.95 including shipping. It even comes packed in a nice cardboard box - how appropriate!
I tried the included lenses in the pizza box Cardboard, and they made a world of difference!

V-Strom Fairing

Battery Monitor Voltmeter for 12v Lighter Socket

This is a plug-in voltmeter for monitoring battery voltage. It plugs into a standard cigarette lighter socket.

This is what it looks like in operation. (My battery is getting weak.)

The LED voltmeter module came from Deal Extreme (dx.com). Item: RD04 Mini 0.36" Yellow LED Digital Voltage Measuring Meter Module - Black + Blue-223908 Cost: $4.11 The case is made from Lexan polycarbonate .093" thick sheet plastic. It is glued together with 5-minute epoxy. I found that using a utility knife to scribe straight lines, clamping the sheet along the scribed line between two boards, and bending the sheet until it snapped off, worked well for cutting the pieces. I sanded the edges to make them square and flat, using a sheet of 100 grit sandpaper on a granite tile.

The meter box is mounted on a Philmore 48-700 "Auto Power Plug", from Altex Electronics. Cost: about $3.20. I cut the plug off 1 inch from the cord end, to leave a 0.2 inch portion of the flatted cylinder portion.

Here is the drawing of the plastic parts. The oval opening in the bottom had to be trimmed out slightly larger than shown; I used a 'Dremel' tool.

The LED module has three wires. The black goes to the ground connection in the plug, and the red and blue wires both go to the +12 (center pin) connection.

PWM Grip and Jacket Heater Controller

A variable output controller for grip heaters or heated clothing costs around $75. We decided to build our own.

We found this schematic at http://www.dprg.org/tutorials/2005-11a/index.html. This is a "Pulse Width Modulation (PWM)" power controller. It is basically an oscillator which switches the power transistor on and off with the relation between on time and off time ("duty cycle") set by the potentiometer position.

In the schematic, the "DC Motor" represents the power load, which actually will be the heating element. Another modification is the potentiometer has a SPST switch which is used to control power to the circuit. In the case of the grip heaters, where the load is permanently connected, a relay is used to connect power to the load (called "+V MOTOR" in the diagram above.) This is done to prevent any possible drain on the battery when the grip heaters are not being used. Finally, the C1 capacitor was changed from 0.1 to 10.0 uF in order to slow the pulse rate down (from about 144 Hz to 1.4 Hz) so as to prevent possible disturbance to the motorcycle electronics.

(To be continued.) The grip heater controller was built and is in operation. Unfortunately, we forgot to take any photos. Hopefully, there will be construction photos of the jacket controller...

Heated Jacket Liner

This is a DIY heated jacket liner for use under our motorcycle jacket.

It was constructed by stitching a 20 foot length of heater wire from a defunct electric blanket to the inside of the red windbreaker. The green windbreaker was sewn inside the red one to protect the wires.

The white wire is the heating element. The black one is an 18AWG wire running from one end of the heating wire to the external connector at the bottom of the jacket.
Here is the routing of the wires.

The electric blanket wire is a twin conductor wire. Each conductor is made of a pair of 36 AWG strands spiral wound around what appears to be a nylon fiber core, and coated with a plastic insulation of some sort.

The external connector is a 5.5 x 2.1 mm DC power connector - similar to those used for laptop computer power supplies.

Each conductor of the heating wire has a room temperature resistance of approximately .24 ohms/foot. In the jacket, the two conductors are wired in parallel, giving a total resistance (with connections) of approximately 2.5 ohms. At 12 volts, the current starts at 4.8 amps, resulting in an initial power of 58 watts.
As the jacket heats up, the resistance increases slightly, dropping the power to around 47 watts. That is pretty low for a jacket; 70-90 watts is more typical. But as this was the first try, 47 is acceptable. It produces a noticeable amount of warmth.