LA6NCA

LA6NCA - 6L6, SI5351 CW Transmitter

I have designed a new transmitter.
The oscillator consists of a modern SI5351 and output stage
consists of a tube design from ARRL handbook 1955.




The transmitter is set to my favorite frequency, 3570 kHz.




When I press down the key, the frequency disappears from the display and
an instrument shows the output voltage.
I tun the output after this display.
The great instrument showing cathode current dip is therefore unnecessary.






I am testing the transmitter with E52b receiver.
The first QSO was with LA9IAA and he could report very good signals.
Very good tone and no key click.


I have used my old AM / CW transmitter for this project.
I have mounted a modern oscillator and mounted a 300 volt power into the transmitter.





Here we see the oscillator, power and transmitter from 1955 connected.










To the left is the modern processor controlled oscillator.
To the right is the transmitter from the 50's.



Here is the Arduino processor and display.
It is a TFT display with I2C interface for the Arduino.
The frequency setting buttons are connected to the Arduino.
It's also the CW key.



Here I have also mounted the oscillator. It is also controlled on the same I2C bus.




The 6L6 transmitter is now installed at LA9LE.




The 6L6 transmitter is connected to my automatic RX / TX switch.


LA6NCA - 6L6, CW and AM Transmitter



Transmitter with Xtal oscillator.
The BOX comes from IKEA. Price is 3 $.


I have here made an AM / CW transmitter described in the 1955 ARRL manual.
I have only used parts from my junk box. I am using a RADIONETTE
amplifier with 2 x 6L6 output tubes as power. The oscillator gets power from
middle output of the output transformer. The output amplifier with 6L6 get
power from one side of the output transformer on the RADIONETTE.
This gives a very good AM quality.
I then connect a microphone to the amplifier, and I get an AM modulator.
The box is from IKEA to approx. 3$.




Two tube CW transmitter. Xtal oscillator - 6AG7. Power amplifier - 6L6.





6L6 transmitter, bottom view.


Here is my new 6L6 AM and CW station.I use a BC-348-N as receiver.
A Radionette amplifier from the 50’s is power and modulator for the 6L6 transmitter.





This is my first test of the 6L6 station. QSO with LA5FH in Larvik and LA9WNA in Skien.




Power and modulator. Radionette amplifier.




This fig. show how I use the amplifier as a power and AM modulator.
Power to the oscillator is taken from the centre tap of the output transformer.
Power to the transmitter 6L6 is taken from one of the 6L6 in the amplifier.




ECC83, EF86 and 2 x 6L6 in the output.


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