Western Electric 3A tennis ball vacuum tube. Two wire leads.radio valve, western electric, vacuum tube, 3a

Western Electric 242C vacuum cylindrical tube. four plugs in the basewestern electric, 242c, vacuum tube

Crookes Vacuum tube

Crooke's Vacuum Tubes

Crooke's Vacuum tube

Crooke's Vacuum tube

Crooke's Vacuum tube

Crooke's Vacuum tube

Croooke's Vacuum tube

Crooke's Vacuum tube

Crooke's Vacuum tube

Crooke's Vacuum Tubes, set of 15. Used in lecture demos.to illustrate discharge in gas

Western Electric 4205E tennis ball with nipple on top, vacuum tube. Base Europe 4-Pin B4. filament: Vf 4.5 volts/lf 1.6 Ampere. western electric, radio valve, 4205e

Stand for Vacuum or X-Ray Tubes.

Part of the original cardboard box for the Western Electric 242C vacuum tube. western electric, vacuum tube, 242c

Crooke's Vacuum tube

This item was used at the Ballarat School of Mines Physics department until the 1970s-1980s to demonstrate that electrons have a straight line. A sealed conical glass tube, equipped with two electrical connections. One, at the narrow end, terminated inside with a sic shape electrode and faces a cross-shapped aluminium steel target near wide end. Other electrode is side branch, which also provided means of mounting on a polished wood circular stand. A Crookes Tube is an early experimental electrical discharge tube, with partial vacuum, invented by English physicist William Crookes and others around 1869-1875, in which cathode rays, streams of electrons, were discovered. May also be called a Crookes–Hittorf tube or Maltese Cross Tubemaltese cross, crookes tube, physics, electron emission demonstration, cathode rays, vacuum tube, electrons, crookes–hittorf tube, maltese cross tube

A Crookes tube is an early experimental electrical discharge tube, invented by English physicist William Crookes and others around 1869-1875, in which cathode rays, streams of electrons, were discovered. Wilhelm Röntgen discovered X-rays using the Crookes tube in 1895. The term is also used for the first generation, cold cathode X-ray tubes, which evolved from the experimental Crookes tubes and were used until about 1920.(http://en.wikipedia.org/wiki/Crookes_tube)Glass vacuum tube with a metal maltese cross inside. The tube is on a timber stand.scientific instruments, crookes tube, science, maltese cross, scientific objects

Although Lee DeForest invented the triode vacuum  in 1906, it was not employed in hearing aids until 1921. The first hearing aid using a vacuum tube was purported to have been made by Earl C. Hanson. He called his hearing aid the Vactuphone. It used one small peanut tube (below right) to amplify the output of a carbon hearing aid. The Globe Hearing Aid Company and Western Electric collaborated to manufacture the Vactuphone. By the early 1940s, Raytheon had developed miniature vacuum tubes. It was these miniature vacuum tubes that made body-worn hearing aids a reality. Unfortunately, the power requirements of these aids made it necessary to use two relatively large batteries—an "A" battery to power the filaments of the vacuum tubes and a "B" battery to supply the high-voltage for the plate current. The batteries were worn external to the hearing aid itself and the name "Two-piece" hearing aid was used to describe them. Until about 1945 "Two-piece" hearing aids were the norm. However, improved vacuum tube design reduced current requirements. As a result, battery manufacturers were able to reduce the size of the batteries used in hearing aids. At the same time, electronic components were also being miniaturized. This allowed the hearing aid manufacturers to design hearing aids with internal batteries. After 1945, these "One-piece" hearing aids quickly replaced the more cumbersome "Two-piece" hearing aids. With continuing improvements in both batteries and components, hearing aids continued to reduce in size until 1953 when the vacuum tube was suddenly supplanted by the transistor.Fawn plastic hearing aid with metal clip on back and wires leading from the bottom. Made in the USA, sold by Angus & Coote as the Sole Australian Agents. The Model is the Sonotone 700. Two dials one on each of the top corners."ANGUS & COOTE/Sole Australian/Agents/C D C" Printed in black on the back, top left hand corner. "SONOTONE/700/SERIAL NO/843218/MAD IN U.S.A./SEE PATENT NOTICE/IN INSTRUCTION BOOK" imprinted on back, centre middle.deaf children australia, hearing aid, sonotone hearing aid, sonotone 700, angus & coote

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids. A Widex 25 hearing aid from the 1950's made in Denmark. Brown and gold metallic casing with a volume control dial and an on/off switch. The curly wire runs to a circular outer disc. Although not present the disc would normally connect to an ear mould which is individually fitted to the wearer. The item comes in a soft leather case."DENMARK" inscribed on gold front. "WIDEX 25" inscribed on back. "WIDEX" on inside cover of case. "W" on outside cover of case device, hearing aid, loss, hard of hearing, deaf children australia, victorian school for deaf children, vsdc, denmark, widex

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids. Hearing aid with Pink and silver metal pack with attached wire to ear piece. Uses (A) battery. Ear piece moulded for wearer with dials for adjustments. In original box. Transitone and Universal Hearing Aids were manufactured by British Hearing Aids (Aust) P/L. Model 61T. NoV848 "TRANSITONE & UNIVERSAL/HEARING AIDS/BRITISH HEARING AIDS (AUST) P/L" printed on fabric inside lid of box. Inside battery compartment, label "MODEL 61T" ('T' handwritten) "V848" inscribed on hinge.

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids. A new aid type, the Calaid V, was introduced featuring a forward facing microphone, and three potentiometers for adjustment of maximum gain, maximum power output, and low frequency roll off. The Calaid V was introduced in the early 1980s and remained the most frequently used aid in NAL's service for the next ten years (From: THE CALAID: AUSTRALIA'S OWN HEARING AID by Laurie Upfold and Ray Piesse Single Behind-the-ear hearing aid. Provided and manufactured by the NAL (National Acoustic Laboratories), part of the Commonwealth Department of Health. "CALAID/V" on bottom face

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids. Part of the development of hearing aids Gold and burgundy metal casing, with an ear piece attached by wire. This is a body-worn hearing aid, with user instruction booklet. Manufactured by Rexton a subsidiary of Siemens."647 IV" on bottom of case, along with controls, "H N L" "M T O" and a numbered dial deaf children australia, hearing aid, rexton, siemens

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids. A Universal hearing aid supplied by Angus & Coote Hearing Aids. Universal Hearing Aids were manufactured by British Hearing Aids (Aust) P/L. Includes ear mould for right ear. In a teal leather box. ""Universal"/Mod 73-824" on back of pack. "Angus & Coote/HEARING AIDS" on inside of case.

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids. Tan plastic case hearing aid, with wire, ear piece and ear mold with metal clip. Made in England and sold by Myer Hearing Service. "MYER/HEARING SERVICE" engraved in gold on case. "MADE IN ENGLAND" on bottom of case. deaf children australia, hearing aid, myer hearing service

The first all transistor hearing aids appeared in 1953. They were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. The vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items. There were body hearing aids where the earpiece was connected to the hearing aid and battery pack worn on the body. Ear level hearing aids consisted of eyeglass, behind the ear (BTE), in the ear (ITE), and in the canal (ITC, CIC) hearing aids.Cream plastic hearing aid with metal back. Takes 3 batteries and there is a piece of paper in the battery case advising 'CAUTION'. Two round knobs on top, 'ON/OFF' and the other I assume is Volume. There is a plastic tag for attaching to a button (probably), headphone sockets. The front is metal lacework with a scrolled 'Z'"Z" on front. "ZEPHYR/HEARING AID/2546" on back. "U C"/"M"/"7777" on inside battery case.deaf children australia, hearing aid, zephyr hearing aid

Two variable vacuum discharge tubes (cathode ray tubes?). Two glass tubes, each with foil leaf electrodes inserted at opposite ends. scientific instruments, physics, electron discharge tube

The first electrical hearing aids were carbon and were made possible by the invention of the carbon microphone and were made between 1900 and 1939. Carbon, which can be made to amplify electrical current, was used to provide some amplification prior to the invention of vacuum tubes. Later models often came with mechanical (carbon) amplifiers to try to boost the amount of amplification. The carbon microphone was originally invented for use in the telephone and had the properties of being able to modulate current. It is this property that made it useful in the early electrical hearing aids. An example of a carbon hearing aid. This has an imitation tortoise shell casing. Round dark red and black imitation tortoise shell carbon hearing aid with clip for attaching to clothing, and a slide for adjusting the sound (?) a cord split between a plug and a speaker (?)."SONOTONE/REG U.S.P.A./292392/MADE IN U.S.A./ELMSFORD, N.Y." on bottom of unit. "SONOTONE" on plug. "PAT RE 21030" on speaker? deaf children australia, hearing aid, sonotone