Electrical discharge through gases is studied by using a specially designed glass tube commonly called a discharge tube. The air inside the tube can be pumped out by connecting the side tube to a vacuum pump, and the desired pressure can be maintained inside the tube.

Rami Arieli: “The Laser Adventure” The role of the Helium gas in He-Ne laser is to increase the efficiency of the lasing process. Two effects make Helium particularly valuable: The direct excitation of Neon gas is inefficient, but the direct excitation of He gas atoms is very efficient.

In the helium–neon laser, the gain is an inverse function of the diameter of the gas tube, because the lower level of the laser transition is depopulated by collisions of the neon atoms with the walls of the tube. In order that the collision rate of neon atoms with the wall be high, the tube diameter must be small.

A laser tube is mounted on an optical bench so that one of its end mirrors is mounted externally to the tube on an optical bench sliding holder. Careful alignment of the external mirror starts the lasing action, as long as the open part of the lasing cavity is not blocked.

: an electron tube which contains gas or vapor at low pressure and through which conduction takes place when a high voltage is applied.

A specialized type of gas-filled tube called a Gas Discharge Tube (GDT) is fabricated for use as surge protectors, to limit voltage surges in electrical and electronic circuits.

Discharge tubes can be used to prevent current flow below a certain voltage; they can also function as lamps by the use of ionizing gas, which glows when current flows through the tube.

A gas- discharge tube is usually a glass tube with two electrodes sealed through its walls. When a voltage is applied to the two electrodes and the pressure of the gas in the tube is reduced, eventually a pressure is reached at which a current flows, and the gas begins to glow.

Argon

Color

Agas-filled tube is essentially a vacuum tube having a small amount of some inert gas at low pressure. The gas pressure in a gas-filled tube usually ranges from 10 mm of Hg to 50 mm.

AFAIK, these are all voltage regulator tubes and have the standard radiation symbol printed on them (unless it has worn off). 3) CRTs. These are dangerous because of their size and that they contain a vacuum. They can implode (not explode) violently if broken.

In a discharge tube ionization of enclosed gas is produced due to collisions between. These free electrons can further liberate ions from gas molecules through collisions. The positive ions are attracted towards the cathode and negatively electrons move towards anode . Thus , ionization of gas results.

A tube that is glowing blue is often wrongly perceived as a defect, however, it’s really just a side effect of a power tube — a fluorescent glow in the blue spectrum. It actually indicates that the vacuum inside the tube is very good, which is what allows this phenomenon to occur.

When a vacuum tube develops an air leak (a small crack or bad seal by a pin for example) this getter color will change to pure white. If you see this you know with 100% certainty that the tube is bad. Third, look for a purple glow that is very focused around specific elements inside the tube.

Crackling, squeals and feedback, excessive noise and muddiness or low output are all evidence of tube problems. Power tubes. The two main symptoms of a power tube problem are a blown fuse or a tube that begins to glow cherry red. If it happens again, replace the tubes before using the amp again.

A: These are the most common signs that tubes need replacement:

• Excessive noise (hiss, hum) including squealing or microphonic tubes.
• Loss of high end.
• A muddy bottom end; Sounds like there is too much bass and note clarity is lost.
• Erratic changes in the overall volume.
• The amp doesn’t work!

How do I know when my tubes need replacing? Power tubes like EL34’s and KT88’s are good for about 2500 hours or more. But may go longer in an amplifier with a conservative design. Small signal tubes with numbers like 12AX7, 12AU7, and 6922, and rectifier tubes like 5AR4 may go 10,000 hours.

eight hours

You can expect a conventional amplifier tube to have a service life ranging up to 10,000 hours. Tubes with military specifications are built to last up to 100,000 hours.

You should be looking anywhere from $50 (for smaller amps like a 30 watter)) to $130ish (For larger amps.

Tech labor is typically $50-100 an hour, plus cost of parts. This is why some techs will turn down certain ‘cheap amps’ mainly because it’s not worth it to the customer, and some may think it’s unfair, or like they’re being ripped off, if they need to pay $200 for a repair on an amp they paid $300 for.

An amp is the sum of its parts. Its part will wear out, so the amp will wear out. Using the amp more, and playing it louder, will contribute to wear on its components.

If we are talking home music systems, the reason for the old amplifiers sounding better is simply build quality. the best old amps use transistors run in what is called class A; -that is, they have access top the full power of the amp at all times. They are not very energy efficient, but they sound great.

10 to 20 years

Capacitors may last 30 years – what u are doing in replacing them every 10 years is avoiding the potential of catastrophic failure. With regard to filter caps, it is best to play an amp 1-2 times a year at minimum.