A tikker, alternately spelled ticker, was a vibrating interrupter used in early wireless telegraphy radio receivers such as crystal radio receivers in order to receive continuous wave (CW) radiotelegraphy signals.
In the early years of the 20th century, before modern AM or FM radio transmission was developed, radio transmitters communicated information by radiotelegraphy; the transmitter was switched off and on by the operator with a telegraph key, producing pulses of radio waves, to spell out text messages in Morse code. Around 1905 the first continuous wave radio transmitters began to replace the earlier spark transmitters. The Morse code signal of the spark transmitter consisted of pulses of radio waves called damped waves which repeated at an audio rate, so they were audible as a buzz or tone in a receiver's earphones. In contrast the new continuous wave transmitters produced a signal consisting of pulses of continuous waves, unmodulated sinusoidal carrier waves, which were inaudible in the earphones.[1] So to receive this new modulation method, the receiver had to produce a tone during the pulses of carrier.
The "tikker", invented in 1908 by Valdemar Poulsen, was the first primitive device that did this. It consisted of a vibrating switch contact between the receiver's detector and earphone, which was repeatedly opened by an electromagnet. It functioned as a crude modulator; it interrupted the signal from the detector at an audio rate, producing a buzz in the earphone whenever the carrier was present. Thus the "dots" and "dashes" of the Morse code were made audible.
Around 1915 the tikker was replaced by a better means of accomplishing the same thing; the heterodyne receiver invented by Reginald Fessenden in 1902. In this an electronic oscillator generated a radio signal at a frequency fo offset from the incoming radio wave carrier fC. This was applied to the rectifying detector with the radio carrier. In the detector the two signals mixed, creating a heterodyne (beat) signal at the difference fC - fC between these frequencies, which was in the audio frequency range. The heterodyne provided the audible tone in the earphone whenever the carrier was present. After vacuum tube oscillators were invented in 1913 by Alexander Meissner the heterodyne receiver replaced the tikker. Today the heterodyne method is still used to receive CW signals, and the beat frequency oscillator (BFO) is a standard part of all communications receivers.
^K. G. Beauchamp,History of telegraphy, IET, 2001 ISBN 0-85296-792-6, page 201
A tikker, alternately spelled ticker, was a vibrating interrupter used in early wireless telegraphy radio receivers such as crystal radio receivers in...
April 25, 2012. Retrieved September 12, 2011. "Robert D. Tikker - Experience" (PDF). Tikker Engineering. Archived from the original (PDF) on June 12,...
the capital Nahan, Paonta Sahib, LANA PALAR, Tuheri, Bhawan, Shamra, UchaTikker and Suketi, the latter known for Shivalik Fossil Park. There are seven tehsils...
temples to Kheer Bhawani in the region, such as Mata Kheer Bhawani Temple at Tikker, Kupwara. The temple is one of the most important temples for Kashmiri Hindus...
modulation The CW Operators' Club Damped wave On-off keying Periodic function Tikker Types of radio emissions Waveform "Continuous wave". The Free Dictionary...
http://tourism.webindia123.com/tourism/hillstations/Morni/index.htm Morni Hills "Tikker lake". Archived from the original on 17 May 2017. Retrieved 14 April 2016...
during the pulses of carrier. The first crude device that did this was the tikker, invented in 1908 by Valdemar Poulsen. This was a vibrating interrupter...
the Kashmiri saint Swami Nand Lal Ji moved some of the stone idols to Tikker in Kupwara. Some of those were subsequently moved to Devibal in Baramulla...
temples to Kheer Bhawani in the region, such as Mata Kheer Bhawani Temple at Tikker, Kupwara. The Chenab valley is a region which refers to districts of Doda...
was a lot of attenuation. History of radio Transmitter Mercury arc valve Tikker US 789449, Poulsen, Valdemar, "Method of producing alternating currents...
Ellen Ruth Harrison for That Line Which Is Earth's Shadow 1994: Timothy Tikker for Variations SUr Un Vieux Noel 1996: Robert Greenlee for Three Spirituals...
geomagnetic field means that the conductivity of the ionosphere is anisotropic. Tikker Biography from the IEEE History Center retrieved 2011 Sept 28 Pedersen,...
van Oscar Kristelijn (1998) Bergweg 17, Bosweg 19 (1999) Mijn leven met Tikker (1999) Engelen van het duister (2001) Margaretha (2002) Knielen op een bed...
Magnano, Italy (2015), published 2017. "Recollections of Edwin Fischer" (T. Tikker), Journal of the American Liszt Society, vol. 21, January−June 1987. "Bach...
(2) a variable condensor with rotating plates (slope demodulation), (3) a tikker, (4) a separate heterodyne, and (5) the autodyne. Fessenden researched the...
organ Seattle Pacific University, Seattle, OR, practice organ Harlow, J. & Tikker, T. residence, Charleston, SC Pacific Lutheran University, Parkland, WA...
the Eastman School of Music "Women in Music Festival" Organist: Timothy Tikker Accompanied by: University of Rochester Symphonic Orchestra conducted by...