All I was simulating (with LTspice) a three phase power supply where the secondary is in star configuration with full wave rectification. You can get also a second voltage from this by connecting to
I was simulating (with LTspice) a three phase power supply where the secondary is in star configuration with full wave rectification. You can get also a second voltage from this by connecting to the
You don't hear the ripple because it does not modulate the linear amplifier. If you were to run the amplifier in a non-linear mode such as class C then it would plate modulate it. 73 Gary K4FMX _____
Hi Gary, All I was thinking about your statement and looking a typical tube anode characteristics (curves).If I read this correctly, change in plate voltage does cause a change in plate current.Is th
Hi All, even if the plate current did not change, wouldn't the changing plate voltage result in changing power input and corresponding changes in power output? That sounds like modulation as well. Ta
It is a matter of degree. If the tube is operating in class-C it is swinging from saturation to cut-off similar to a switch. The voltage that appears on the plate swings about the range of the power
AM modulation is a multiplication (mixing) process. Without a switch (amplifier driven into cutoff) there is no multiplication of the signals. The variation in plate voltage due to power supply rippl
Because of the relatively high plate impedance of a tetrode or pentode, modulating plate voltage without modulating screen voltage has a relatively small effect. Which is why plate and screen modulat
Makes one wonder if the receive mixers and product detector would provide the mixing process to produce hum sidebands. This is an interesting aspect of rf design that I personally have never studied
Seems that the receiver mixers and demodulator would provide this mixing/multiplicaton action and introduce apparent hum modulation of the signal. This is an interesting aspect of rf design that I ha
A diode detector would if the hum signal was present. But if no mixing occurs in the transmitter, the low frequency (hum) signal is eliminated in the transmitters output circuit as the audio frequenc
Gary, ALL As far as I understand modulation, mixing and multiplication are just about the same thing. So, if there is an input port to an amplifier that changes the gain or in other words the output
Hi All, an added thought about the ripple effects: The ripple voltage is highly dependant on plate current. Considering the nature of SSB speech wave forms, the maximum ripple voltage only occurs on
Modulation and demodulation can take place by: 1. Modulating the gain of a device 2. Modulating its output impedance 3. A Nonlinearity that includes a squared ( second order term) or for IMD or cross
My current interest is mainly in microwave eme operation. Traveling wave tubes are used to generate power. The homebrew power supplies have a lot of filter C in the helix supply to reduce hum on the
Jim, it is not that simple. The there is about 9000vdc and normal helix current is less than 5mA. Right now there is a 12.5K ohm glitch resistor to limit any fault current but that is not enough to f
GM3SEK et all will no doubt chime in and provide the correct url. That will shut it down asap..quick like. The V drop across a sense resistor in series with the B+ is fed to the control circuit. The
Small degree of modulation of the Helix supply would be bad. The helix supply accelerates the electrons to establish a velocity that matches that of the wave traveling along the helix. If those veloc
Hi all, let me add my way to see this ripple modulation matter: First, let's think tubes. In a tube, cathode current flow depends on the electric field around the cathode, which is created by the com
Gerald, Ripple on the helix will produce phase modulation - a well known function of the TWT used in the Serrodyne. (An electronic warfare approach, where you receive the radar signal, amplify it in