Category Archives: Uncategorized

Ford car 6000cd radio hack

Have you ever wanted to just plug your phone / audio device straight into a car radio. Here are the details to connect a 2.5mm audio jack or Bluetooth receiver into a standard car radio. The car is a Ford focus 2003 the radio model is a 6000cd. The pictures below show the solder points. there are 4 points that represent each speaker. So if you had a quadraphonic input source you could have it control each speaker individually. However, I am using a stereo Bluetooth output device so I paired red and white and black and red (thicker) together.

There are 4 connectors solder point inside the radio that will amplify a standard line signal.

Viceroy Lathe details. T.D.S 1 S.C.L

Imperial gearing thread chart.
Metric gearing thread chart.

Here is a gearing program that runs on Linux (wine) or Windows that can be used to deduce other gear combinations. Note that the 127/100 compound gear is not used. This magical gear is what makes the lathe exactly metric. The lathe, like most, has an 8 TPI imperial lead screw. The 127/100 effectively allows the imperial lead screw to have a 100 metric divisions. This is because 1 inch is equal to 25.4 mm and therefore 50 inches is exactly 127 centimeters. Therefore, 254 / 2 is 127 and 127 is prime. Which means its not possible to get a smaller gear that will divide exactly.

lead screwinchesmmequivalent teeth
on theoretical
compound gear

As you can see the table above lists theoretical gears with impractical numbers of teeth. This is made practical by another compound gear the 72 / 18 which is a ratio of a 1 / 4. 12.7mm / 508 is 0.25 which provides the metric basis to work with. The other gears provide ratios of on this.

This is a link to an online gear calculator.

Solar Evacuated Tube Collector (ETC) technology

Over the weekend we have almost perfect sun shine. So I collected some data on a 20 Tube solar collector. Here are the results.

Temp inTemp outdifference

The pump rate was at 6 liters per minute (0.1 liters second). So give this its possible to work out how much of the suns energy was being captured. We just need to know one more thing. The specific heat capacity of water. Which is 4.2 Kj / Kg / degree C. That is 4.2 kilo Jules per kilogram per degree C.

So the calculation turns out to be.

Total Energy per second = (Specific heat capacity of water) x (Liters per second) x (Temperature difference)

1.68 kW = 4.2 * 0.1 * 4

Microwave repair

It turns out that a microwave can be easily fixed. The symptoms are luke-warm food.

Here from the image above you can see the cracks in the magnets. These develop because the heating and cooling of them over time fatigue the fragile compound they are made from. I therefore, bought a new Magnetron (love that word) and plugged it in. It has now been working for over a year without issue.

Quad copter designed for flight longevity

The specification of the quad are as follows.

Load: 10.64 C Voltage: 14.28 V Rated Voltage: 14.80 V Energy: 62.16 Wh Total Capacity: 4200 mAh Used Capacity: 3570 mAh min. Flight Time: 4.8 min Mixed Flight Time: 16.9 min Hover Flight Time: 32.9 min Weight: 452 g   15.9 oz
 Motor @ Optimum Efficiency Current: 4.68 A Voltage: 14.55 V Revolutions*: 4886 rpm electric Power: 68.1 W mech. Power: 59.3 W Efficiency: 87.0 %  Motor @ Maximum Current: 11.18 A Voltage: 14.21 V Revolutions*: 4274 rpm electric Power: 158.9 W mech. Power: 129.1 W Power-Weight: 508.3 W/kg   230.6 W/lb Efficiency: 81.2 % est. Temperature: 43 °C   109 °F  
Wattmeter readings Current: 44.72 A Voltage: 14.28 V Power: 638.6 W
 Motor @ Hover Current: 1.63 A Voltage: 14.71 V Revolutions*: 2027 rpm Throttle (log): 26 % Throttle (linear): 44 % electric Power: 23.9 W mech. Power: 19.4 W Power-Weight: 77.1 W/kg   35 W/lb Efficiency: 81.2 % est. Temperature: 28 °C   82 °F specific Thrust: 13.05 g/W   0.46 oz/W  Total Drive Drive Weight: 1069 g   37.7 oz Thrust-Weight: 3.5 : 1 Current @ Hover: 6.51 A P(in) @ Hover: 96.3 W P(out) @ Hover: 77.8 W Efficiency @ Hover: 80.7 % Current @ max: 44.70 A P(in) @ max: 661.6 W P(out) @ max: 516.2 W Efficiency @ max: 78.0 %  Multicopter All-up Weight: 1250 g   44.1 oz add. Payload: 2541 g   89.6 oz max Tilt: 71 ° max. Speed: 40 km/h   24.8 mph est. rate of climb: 5.0 m/s   984 ft/min Total Disc Area: 58.58 dm² 907.99 in² with Rotor fail:

RCTimer motors 5010 motors 360

17″ Carbon fiber propellers blades.

Carbon fiber frame

Here is the eCalc link to an online calculator that can be used to approximate the build and estimate its flight capabilities.

FPV in stanford-le-hope


I woke early today to test video recording with the Raspberry pi. Using the camera module. Here is the video below. It is quite shaky but it was also a bit windy. I would have liked also to use a gimbal to position the camera. I intend to do this using the two extra channels on the transmitter.

Calibration of Gos 658G Oscilloscope

Realising there is no documentation on the internet to calibrate these oscilloscopes.

I have a GOS 653G Or a (ISO-TECH ISR658G) and wanted to calibrate it. Note that powering up the unit will give better calibration results as the CRT warms up and the power supply reach a static voltage. Ensure this is the case before calibration.

Cursors board

Oscilloscope Cursors board Top back

I have identified 5 variable resistors on the cursors board. This is the board that is controlling the cursors drawn on the screen. There are some things one needs to be aware of when trimming these.

1. The cursors need to be at the extremities of the screen as these need to be aligned to the edge of the graticule.

2. These need to be adjusted with caution and in ratio to the zoom variable resistor located near the CRT tube ref.