Aleksander Burd - website of analog electronics

LCg-serial is a structural LC generator that generates a sinusoidal signal.
This is another structural generator developed by me (the first was LCg-1 - available on the website). LCg-serial, like the earlier LCg-1, is a generator much easier to run compared to classic systems such as Colpitts, Hartley or Meissner. Despite this simplification of the system, it cannot be recommended to electronic beginners, it is required to be familiar with HF circuits. The structure does not contain a reactance divider (Colpitts - capacitors, Hartley - coils) neither a transformer (Meissner). The reactance dividers in the classic oscillators makes it extremely difficult to fine-tune the frequency and the proper amplitude (amplitude small enough to obtain not distorted signal), as they affect both the frequency and the strength of positive feedback. LCg-serial does not cause this problem.


What is the difference between the first LCg-1 oscillator and the LCg-serial?
As the name suggests, the LCg-serial has a serial resonant circuit instead of parallel one. The change of the type of the resonant circuit is not of great utility importance itself. However, by changing to a serial circuit, the LCg-serial got its main advantage: there is no emitter follower attached to the resonant circuit (LCg-1 has such a repeater). Contrary to appearances, it is of great importance at high frequencies - the emitter follower at high frequencies has a negative input resistance (!), which strongly disturbs or prevents the correct operation of the oscillator. There is no such problem in LCg-serial, so you can easily obtain high generation frequencies (the test circuit worked with frequencies up to 700MHz).

    The first version of the LCg-serial generator was created around 2010 and was later used in several designs and in a few diploma thesis, subject to various modifications along the way. LCg-serial is the one of several structural LC generators that I have developed. Some of these schemas will appear on the website later.