Vacuum tubes

[Rusty Heap]

As an electrical engineering student there in school for 7 years on a 4 year plan, does the Name of my fellow nerds engineering softball Teams name of "Inductive Reactance" score me any bonus points?

MP3's suck for data compression.

And the smoothness of tubes verses those harsh over-sampled digital bits transistors, at 44.1 kHz on a CD. oh the humanity...........

RCA patch cords, HDMI vs Fiber Optic audio, Ultra fine multi strand Monster Cable speaker wire woven by virgins in white toga robes, let the discussion and debate continue

[stuartj]

When my firebottles are turned up to 11 they sound firkin awesome.

But they are very very loud.

In regard to guitar amps, digital modelling has come a long way. The AxeFX, for example, is pretty much indistinguishable in sound and behaviour from a valve amp, much more versatile (it can be 1000's of valve amps, cabs, mics.) Its smaller, lighter, more reliable. Its the future, for many. But dear god its complicated.

[beepbeep]

Originally Posted by mreid

TWTs, klystrons, and magnetrons are not vacuum tubes. They are high frequency oscillators used to produce radio waves and radar transmissions.

They are all thermionic devices operating in vacuum. Thus, they could be loosely called "valves" or "tubes". While a magnetron is oscillator , TWT's and klystrons are amplifiers Maybe you got it mixed up with reflex klystrons, which were used as oscillators long time ago.

[T77911S]

Originally Posted by daepp

Not that long ago I heard the FAA was the largest buyer of vacuum tubes on the planet. It was said many were purchased from the Soviets!

i am an FAA electronics tech. not sure how many are still in service, but the old long range radars are probably the last equipment that use conventional tubes as most people know.

we still have radars with very large vacuum tubes that we use a a hoist to pick up and stand about 4ft tall or so. if you saw one you would not know what it was.
we also still use smaller ones that look like ceramic disks with copper type rings for conductors. those are used in interrogation radars to talk to the transponders in planes.

the radar i work on know is ALL digital and computer controlled. although the radar video/coverage is better than analog radar, it really sucks to work on.
just spent 3 days trying to figure out why a computer kept going down.

[911dean]

More tubes

[Don Plumley]

[Wilhelm]

Interesting thread for sure. My hearing is so shot out that I wouldnt be able to tell the difference between a tube amp and a solid state amp !

Questions: Arent those huge high power RF transmitter tubes water cooled? Anyone have a photo of that ?

And does anyone have a photo of the old tube testers that used to be in drug stores and such places?

Thanks !

[herr_oberst]

Originally Posted by Wilhelm

And does anyone have a photo of the old tube testers that used to be in drug stores and such places?

Thanks !

Taa-daa!

[Flieger]

Originally Posted by herr_oberst

Taa-daa!

Looks suspiciously like this ;):

https://www.google.com/search?q=vacuum+tube+tester&client=firefox-a&hs=S0n&rls=org.mozilla:en-US:official&channel=fflb&source=lnms&tbm=isch&sa=X&ei=RDj7UcDlOo3ligKhwoHICQ&ved=0CAkQ_AUoAQ&biw=1280&bih=707

[Wilhelm]

Danke schoen Herr Oberst und Flieger !
Here is the type of tube tester I remember in the drug stores:



Free testing AND a supply of new tubes all in one !

[Schumi]

When I was a kid, from 8-10 years old or so, I had a vac tube collection. Rummaged from old radios, tv sets, etc. I had them all cataloged and liked to build nasty sounding amps and whatnot from various tubes that were never meant for such duty.

I know, I was a really weird kid, just let that go.

I grew out of that stuff by 12 or so when I had moved on to the world of 'modern', digital computers (read: 10 year old IBM that was found in a trash can by my uncle). We moved around this time, and my father asked why I had all the old vacuum tubes. He said I needed to get rid of some junk, and made me throw them out. I obliged, and threw bags and bags of tubes away. It was a shame.

[stuartj]

I went to an airforce museum some years ago and they had a preserved radio, I think dating from the 30s or 40s. It filled whole wall, it had valves 2ft tall and transformers the size of old fashioned TV sets. It looked like a giant guitar amp....back to the future