Vacuum Tubes (Valves)

[John R Retired]

Is there any real world application today where vacuum tubes are more useful than semiconductors?

Or, are tubes completely obsolete and a waste of time and money in todays world?

 

[pete.cal]

There are a lot of audio enthusiasts that believe tubes give a better sound.
I also worked on equipment that was driven into the non-linear range and tubes recovered faster then semiconductors.

 

[crutschow]

Is there any real world application today where vacuum tubes are more useful than semiconductors?

I believe they are still used for high power radio transmitters.

Some audiophile nuts like the "better" sound of tube amps (whatever better is), but you can't beat a high-end solid-state amp for generating a pure, low distortion signal.
If you ever go to an audio show you are unlikely to find any speaker manufacturer demonstrating their speakers with tube amps.

 

[kellys_eye]

Yup, high power RF applications are where they excel. Not so much for their power output but for their ability to withstand 'errors' in tuning (bad VSWR). Today's solid-state systems have to have reliable 'error detection' to shut things down before they blow themselves to pieces!

Plus there is still an avid market in 'antique' radio sets so the tube (valve) market remains strong.

I'm currently building a 4-tube CW receiver from a 1966 magazine article!

 

[John R Retired]

Yup, high power RF applications are where they excel. Not so much for their power output but for their ability to withstand 'errors' in tuning (bad VSWR). Today's solid-state systems have to have reliable 'error detection' to shut things down before they blow themselves to pieces!

Plus there is still an avid market in 'antique' radio sets so the tube (valve) market remains strong.

I'm currently building a 4-tube CW receiver from a 1966 magazine article!

What good is CW today? Unless there is Armageddon and every other RF is out of commission maybe.
Used to be the basic bread & butter of Ham radio and required for an FCC license. Even used in the Navy
with high speed keys.

6L6, 12AX7, Triode, Pentode, grids 1,2 & 3, plate, cathode ray tube..tube testers in drug stores.....the days of old.
Now you need a microscope to see the damn individual components if there are any. Don't sneeze either..

 

[kellys_eye]

CW and the aficionados of it are still around. For me it's related to nostalgia which is something that gets you as you age somewhat.

Not that I'm unfamiliar with SMD too - I've built (and even repaired) some circuits in that format too,

 

[shrtrnd]

I'm just an old *art who was around when vacuum tubes were still taught in school, and was an in-home
TV/radio service tech. Vacuum tubes are infinitely more forgiving when over-stressed than semiconductors.
When somebody finally uses an EMP, your ancient, novelty, laughing-stock old-*arts, are going to be the only ones
still on the airwaves in the affected areas. Laugh it up high-techies.

 

[John R Retired]

I'm just an old *art who was around when vacuum tubes were still taught in school, and was an in-home
TV/radio service tech. Vacuum tubes are infinitely more forgiving when over-stressed than semiconductors.
When somebody finally uses an EMP, your ancient, novelty, laughing-stock old-*arts, are going to be the only ones
still on the airwaves in the affected areas. Laugh it up high-techies.

Like I said above, "Armageddon" when all other RF is out of commission.

 

[John R Retired]

CW and the aficionados of it are still around. For me it's related to nostalgia which is something that gets you as you age somewhat.

Not that I'm unfamiliar with SMD too - I've built (and even repaired) some circuits in that format too,

"Nolstagia"

That is what I referred to in the other thread "modern day use for old electronics technoogy" about ""Other than Nostalgia for old gear"

 

[Audioguru]

Vacuum tubes produce even-harmonics distortion that some old people like to hear like they heard many years ago.
Even-harmonics are musical and are not harsh clipping distortion like an over-driven semiconductor amplifier.

 

[Delta Prime]

I've always wondered why it comes naturally for human beings to consider even harmonics musical enhancing the fundamental frequency while the odd harmonics are rough gritty sandpaper.
It is understood that solid state produces square waves distortion.
But I don't think it's the technology it is how is it implemented or designed.
Growing up with surface mount technology vacuum tubes are not nostalgic for me... Vacuum tube
components became a tool to increase my knowledge base.
When I first came across an vacuum tube, was a heathkit (VTVM) with selenium rectifiers my great-great uncle had.
I learned all about the dangers of high voltage real quick! Your kitchen microwave magnetron is a vacuum tube.

 

[Audioguru]

Most solid state amplifiers produce extremely low distortion. But when the output level is too high for the supply voltage (clipping) then squarewaves with many odd-numbered harmonics are produced. Vacuum tubes can also produce clipping with squarewaves and odd-numbered harmonics but since their power supply voltage is much higher than solid-state then clipping rarely occurs.

 

[danadak]

Is EMP strong enough to burn out filaments in tubes ? Eg, the
Armageddon belief tubes survive ?


Regards, Dana.

 

[Delta Prime]

A (CME) Coronal mass ejection from our son colliding with the Earth's magnetosphere would be one hell of an EMP. I would put good money on vacuum tubes surviving but no one else... Long live vacuum tubes.

 

[kellys_eye]

A (CME) Coronal mass ejection from our son

Wow, is he going to get a telling off.......

 

[danadak]

There must be some real data on this, still curious.

Regards, Dana.

 

[crutschow]

A (CME) Coronal mass ejection from our son colliding with the Earth's magnetosphere would be one hell of an EMP. I would put good money on vacuum tubes surviving but no one else... Long live vacuum tubes.

There are hundreds of satellites in orbit, all with large amounts of semiconductor circuits (no tubes) and they readily survive those CMEs.
I worked on a military satellite with solid-state electronics that was designed to withstand the EMP from a nuclear blast in space, well above what any CME would generate.

 

[Delta Prime]

I worked on a military satellite with solid-state electronics that was designed to withstand the EMP from a nuclear blast in space, well above what any CME would generate

Me too... I still work on military satellites.

. I would put good money on vacuum tubes surviving

Care for a friendly wager?

 

[Delta Prime]

There must be some real data on this, still curious

I'm still looking. But this is rather nostalgic!
Documentation : in 1976 the Electronic Engineering Group EEG ,called 1842 assembled reporting directly to the Commander United States Air Force Communication Service. The electronic Engineering group created a EMP handbook.
It is official documentation.

 

[danadak]

It will be interesting if you can find info. Tubes I assume vulnerable to
filament burnout, but magnetic fields are so much more weaker than
electrostatic, even in a bomb....? So are the bombs capable of creating/
inducing enough current in a filament to burn them out ?


Regards, Dana.