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|Wishing to replace my good old trusty BIRD 43 Watt-meter, I prospected a little on the Internet and found the description of an open source project for a Watt-meter which corresponded perfectly to my needs.
This is a fork of the version made by TF3LJ, and developed by PD0LEW. A new hardware version was subsequently developed by WA2T. I chose the version with an OLED display, but there are versions with touch-sensitive TFT displays.
My previous 10 MHz frequency reference having broken down, the question was whether to repair it or move on.
After reflection, I decided to equip myself with a 10 MHz reference disciplined by GPS (GPSDO) in order to obtain the best possible accuracy.
After some research on the Internet, I found ready-made products at affordable prices and some descriptions of amateur achievements.
I chose the option of making the version proposed by DL4ZAO / DL7UKM . On one hand because there is a detailed description (in German) and that the author offered the printed circuit at a correct price, and on the other hand to learn according to the formula " Build and learn ".
The assembly revolves around an Arduino Nano and software is offered by Michael DL7UKM. All the more reason for my choice, now having a good knowledge of this platform.
Here is the description of a simple capacitance and inductance meter, easy to build, based around a PIC microcontroler. Simplicity does not mean poor characteristics. The precision is very good and even better than many commercial LCmeter !
The original description has been done by Phil Rice VK3BHR on his pages. I only did adapt it to my needs.
Here are the main characteristics :
The orinality of this description is that the tone generation is made by the use of a DDS and not a sine wave generator made with transistors or a special circuit. It also does not use any special and expensive component but only junk box components, or at least cheap ones !
The main characteristics of this generator are :
- Two tone generator 800/ 1000 Hz or 400/2600 Hz (jumper selectable)
- Single tone generator of 1000 Hz
- Ajustable output level, max around 100 mV pp on 600 Ohm, or 35,4 mV eff. in single tone or 25,0 mV eff. in 2 tones
- Spectral purity between 0,3 and 150 kHz > 50dB !
- Distorsion <0,01% (in single tone) !
- Supplied by a 9V battery, consumption 7-8 mA that gives 50 working hours with an alcaline battery.
- Automatic PTT switching at power on.
This circuit has originaly been described by DH7AHN ,adapted and translated by myself for my usage. The original description can be found hereWrite comment (2 Comments)