Tag Archives: Diode

FLYBACK DIODE USED ON RELAY CIRCUITS

The chatter of a relay is not often heard in the modern ham radio, but when I first got my amateur radio license there would most likely be more then one relay circuit somewhere in the shack. Today, most of … Continue reading

Posted in Amateur radio, Ham Radio, Relay | Tagged , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Dealing With Secondary Emission in Tetrodes

As we saw in earlier posts the diode vacuum tube (or valve) became a triode by inserting a grid, known as the control grid, which allowed it to amplify audio and RF signals. The triode had a problem of interelectrode … Continue reading

Posted in Amateur radio, Ham Radio | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Let’s Add Another Grid to The Triode

Lee DeForest added the grid to the diode in 1908 and at that time radio signals below 200 meters (today we would say above 1.5 MHz remember as frequency goes up wave length goes down) was considered very high frequencies. … Continue reading

Posted in Amateur radio, Ham Radio | Tagged , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

The Vacuum Tube Diode

To start understanding the operation of the vacuum tube we must start with the diode meaning two elements or two electrodes. These two electrodes are the cathode and the anode more commonly known as the plate. There is the requirement … Continue reading

Posted in Amateur radio, Ham Radio | Tagged , , , , , , , , , , , , , , | Leave a comment

WHAT IS A NUVISTOR?

From the time Lee De Forest put a grid in the diode detector which he patent in 1906 to build the first audion (what he named the first triode which he patent in 1908) amplifier engineers have struggled to build … Continue reading

Posted in Ham Radio | Tagged , , , , , , , , , , , | 34 Comments

DIODE DESIGNED TO ACT AS A CAPACITOR

When I was first licensed transmitters and receivers used a variable capacitor with a shaft that came out to the front of the radio that had knob attached to it to change frequency.  Most modern radios have synthesizers to determine … Continue reading

Posted in Ham Radio | Tagged , , , , , , , , , , , , , , , | 2 Comments

DIODE DESIGNED TO ACT AS A VOLTAGE REGULATOR

In the days of vacuum tubes gas filled tubes were used as voltage regulators and they were effective for the need of the time. A tube normally runs at a much higher voltage then a solid state device and at … Continue reading

Posted in Ham Radio | Tagged , , , , , , , , | 9 Comments

THE TUNNEL DIODE

A standard NP junction diode will maintain a forward voltage drop of about .2 volts for a germanium diode and about .6 volts for a silicone diode. If you have a voltage source that is connected in series through a … Continue reading

Posted in Ham Radio | Tagged , , , , , , | Leave a comment

THE LOWLY DIODE

  The diode seems to be such a simple device people may wounder how much could be said about the diode.  Well the answer is a lot. Books could be written about the diode, large books.  Not only could books … Continue reading

Posted in Ham Radio | Tagged , , , , , , , , , , | 6 Comments

WHY DOES THE SYMBLE FOR SOLID STATE DIODE APPEAR BACKWARDS?

  Many people who start to learn electronics become confused.  First we teach them that electrical current is composed of a flow of electrons.  We go on to teach that electrons are negatively charged and they move towards the positive … Continue reading

Posted in Ham Radio | Tagged , , , , , , , , | 2 Comments