I enjoy designing devices for use in the shack. The main picture shows an electronic touch paddle, a project I started in April of 2011. It utilizes an 8 bit Microchip RISC processor. Specification for the design are as follows:
Dit / Dash sensor sample rate = 870 uS.
Power consumption @ 9 VDC = 800 uA typ. approx 750 - 800 hrs with standard 9V battery.
Auto shutdown timer of 20 minutes when battery powered. Touching a sensor resets the shutdown timer.
For supply voltages > 10V unit stays powered up no auto shutdown.
LED status for power up, power down and low battery level.
No adjustments necessary. On power up a calibration is perofrmed of both sensors, approx 100 mS total. A momentary switch is used to power on/off the unit. Due to the fast sampling rate of the sensors and fast response, touch to output state, I have no problem using this paddle at 50 WPM which is the max speed of my K3. Battery life is excellent due to the very low current consumption. I have not changed out my 9 volt battery in a year now. My usage is quite high.
For information on my end feed tuners take a look at : http://ham.aditl.com/ham-radio/techie-stuff/efhw-tuner/
I have been using this tuner design for the past 10 years now. I use a much smaller version for my low power and QRP operations.
Below is a picture of a single band tuner, 20M band, used to end feed the driven element of my 2el vertical wire yagi. It is capable of handling 2KW of power with extreamly low loss. Impedance transformation is 3000 ohms to 50 ohms.
73 de Martin/KH6MB
Last modified: 2013-02-03 04:59:52, 1930 bytes cached
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