The original Vail key is on permanent display in the Smithsonian Institute USA

Over at “This Day in History,” the lead story for Jan 6, 2012 was “Morse demonstrates telegraph.” This is a controversial topic since it is said that Vail was the real force behind the system and it is the creator of key parts such as the straight key.

On the Elmering Blog there is a great article that covers the controversial topic.

This is an interesting project. He uses the “SoftRock RX Ensemble II Receiver Kit” to receive the NOAA satellite weather pictures.

For more on the project please visit the following link:
http://alternet.us.com/?p=1398

During our last meeting a few members expressed their interest to learn Morse code. I found a small and simple electronic project that would help with the training. I know this project may be a little over some of our members expertise, but how else do you learn new things?.

On this article the author shows the schematics, list of parts and the source coded he used to build his low cost Morse code trainer. If anyone is interested on building one of these we could order the parts in groups to lower the cost and save on shipping.

Visit this link to read about the project.

The suggestion was to enable TOT on the radio, but the radio is an older  Azden PCS 7000 that does not have this feature.

The way how the PTT is activated from the computer is through the serial port. The signal RTS is set to high and together with the ground it closes the PTT, either by using an opto-coupler or a transistor. The solution I thought about was using the PIC12F683 and is described bellow.

The PIC12F683 is a small 8 pins micro controller. You can define what the pins do and load it in to the part. I used the RTS signal from the computer to power up the PIC. The PIC was loaded with a C++ code that set one output to high, waits 3 minutes and 20 seconds and then set it to low.

The code was written using the demo version of the MikroC from Mikro Elektronika. The demo version is good enough for this little program:


void main() {
ANSEL = 0;          // Turn off analog input
CMCON0 = 0x07;      // Turn off Comparators
TRISIO = 0x00;      // Set all pins as output
GPIO = 0xAA;        // Set Pattern 10101010

Delay_ms( 200000);  // Delay in ms 200000 = 3 mins, 20 seconds
GPIO = ~GPIO;       // Invert pins
}


The components I used were:

1. Radioshack 276-1537 – 9 Position-Male D-Sub connector
2. Radioshack 276-1538 – 9 Position-Female D-Sub connector
3. Radioshack 276-148 – General Purpose Dual PC Board (used only 1)
4. Microchip pic 12F683 – Microchip has free samples, you can buy them from anywhere, mouser, jameco, digikey, etc.

Parts

Besides that you will also need a pic programmer available for purchase on the internet or you can build your own.  Soldering iron, solder and a small amount of wire.

The circuit is as follow:

Schematics

Other pictures:

Back

Front

At the end the project worked as expected on the first test run, cannot complain about that. If you wish to duplicate this and have any questions or comments, please leave a message bellow, I will try to answer your questions.

73′ s de KC2UEZ

If you have more frequencies please leave them as a comment.