Some big transmitting tubes still use filamants. Some of them run at hundreds, or thousands, of amps. Somebody posted a link a while back to a tube that uses something like 25KW of filament power.
John
I just flipped open the old RCA Tube Handbook and found the 5770 power triode which, like most high power transmitting tubes, has a true filament. It runs at 11 AC or DC volts at 285 amperes. Other tubes had filament voltages ranging from 4.5 to 22 volts.
The main advantage of a heater is that it allows the true cathode to be set at a voltage, (within reason), differing from that of the heater. It also allows a selection of the properties of the emitter itself apart from the pure heating function of the separate heater.
-- Virg Wall
Get your facts straight: They were introduced by Galvin. Their car radio product was called Motorola, and later Galvin changed their name to Motorola.
-- You can't have a sense of humor, if you have no sense.
The 35W4 has two filaments. A 29 V and a 6 V for a total of 35 volts. This was done to let the AA5 family of radios use a #47 or similar pilot lamp.
-- You can't have a sense of humor, if you have no sense.
It was a woman's idea in the very early das of retail gasoline sales. Read the history of the Ethyl corporation for the details. They made the lead additive for gasoline, as well.
-- You can't have a sense of humor, if you have no sense.
-- Damn fine catch, Michael! Thanks. :-) news:7l8m12t34nq1ed2393mqq7jhv9hdj@4ax.com
And of course it reduces the hum produced by minor errors in filament placement.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
The police were not radio-ing each other in the 30s.
Heater filaments, idiot.
The term was NOT strictly a description of a photon emitting light bulb component, you dopey f*ck. And a light bulb filament is not for "emitting electrons" either.
They (tube heating elements) were most certainly referred to by both terms, and both were correct.
So, your "Just to be correct..." ISN'T.
No shit, Sherlock.
The filament was never meant to be the emitting element. They were always meant to heat a nearby electrical element. The only reason one sees them on a schematic is because they are heated by an electrical current. They perform no electrical function however. It is purely mechanical, and those mechanics allow the tube to operate in its electrical function properly.
The little Raytheon baby finger sized tubes had odd filament voltages.
He didn't catch it. He lived it.
Wrong again, always wrong. "radio-ing"? Not only are you always wrong but you are stupid too.
Two-way radios begain in early 1933 in Joisey.. and thence nationwide:-
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
This four-pin one is popular with audiop**ls.
eg.
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
If they don't perform no electrical function than where does the required electron cloud mass come from?
Jamie
Amazing that you never figured out how to use google!
California joined the group in 1929. Police cars in San Francisco, Berkeley and Pasadena began to equip their vehicles with radio receivers. Again, these were one-way radios. The first two-way radio was used in Bayonne, New Jersey in 1933. This connected the Police Department to nine of their patrol vehicles.
AlwaysWrong!
John
The first tubes used filamants as the electron source. Big transmitting tunes still do, thoriated tungsten and such.
AlwaysWrong!
John
The cathode is heated, and it is the cathode that emits, idiot. The cathode is part of the electrical circuit and function when IT gets hot enough.
Now look at my remark again, idiot.
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