Ad
related to: stop valve leaks when closed tube frequency is higher than 100 times the amount
Search results
Results From The WOW.Com Content Network
For pentodes, it is higher, about (5-7)/g m. Valves with high g m thus tend to have lower noise at high frequencies. In the audio frequency range (below 1–100 kHz), "1/f" noise becomes dominant, which rises like 1/f. Thus, valves with low noise at high frequency do not necessarily have low noise in the audio frequency range.
Class IV valves have no more than 0.01% leakage under those conditions; this tends to require multiple graphite piston rings or a single Teflon piston ring, and lapped metal seats. Class V valves leak less than 5 × 10 −12 cubic metres, per second, per bar of pressure differential, per millimetre of port diameter, of water when tested at the ...
The grid current drawn in this system is higher than that required for the other two basic designs. Because of this, valves such as the 4CX250B are not suitable for this circuit. This circuit design has been used at 1296 MHz using disk seal triode valves such as the 2C39A.
It therefore adds 1/10 of the noise power caused by the source, and the noise figure is 0.4 dB. For a low-impedance source of 250 Ω, on the other hand, the noise voltage contribution of the tube is 10 times larger than the signal source, so that the noise power is one hundred times larger than that caused by the source.
Figure 2: Windowing a sinusoid causes spectral leakage, even if the sinusoid has an integer number of cycles within a rectangular window. The leakage is evident in the 2nd row, blue trace. It is the same amount as the red trace, which represents a slightly higher frequency that does not have an integer number of cycles.
6N3C power tube. A valve amplifier or tube amplifier is a type of electronic amplifier that uses vacuum tubes to increase the amplitude or power of a signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers in the 1960s and 1970s.
the amount of current that should be considered "100%" has to be known and documented for each tube type (and will be different for different emission test circuit details) The advantage of an emission tester is that from all types of tube testers, it provides the most reliable warning of tube wear-out. If emission is at 70%, transconductance ...
Internal parts of a typical globe valve. The body is the main pressure-containing structure of the valve and the most easily identified as it forms the mass of the valve.It contains all of the valve's internal parts that will come in contact with the substance being controlled by the valve.