Absorption wavemeter

An absorption wavemeter is a simple electronic instrument used to measure the frequency of radio waves. It is an older method of measuring frequency, widely used from the birth of radio in the early 20th century until the 1970s, when the development of inexpensive frequency counters, which have far greater accuracy, made it largely obsolete. A wavemeter consists of an adjustable resonant circuit calibrated in frequency, with a meter or other means to measure the voltage or current in the circuit. When adjusted to resonance with the unknown frequency, the resonant circuit absorbs energy, which is indicated by a dip on the meter. Then the frequency can be read from the dial.

Wavemeters are used for frequency measurements that do not require high accuracy, such as checking that a radio transmitter is operating within its correct frequency band, or checking for harmonics in the output. Many radio amateurs keep them as a simple way to check their output frequency.[1][2][3] Similar devices can be made for detection of mobile phones.[4] As an alternative, a dip meter can be used.

There are two categories of wavemeters: transmission wavemeters, which have an input and an output port and are inserted into the signal path, or absorption wavemeters, which are loosely coupled to the radio frequency source and absorb energy from it.

HF and VHF

A Triplet 3256 wavemeter for use in the high frequency band.
Further information: High frequency and Very high frequency

The most simple form of the device is a variable capacitor with a coil wired across its terminals. Attached to one the terminals of the LC circuit is a diode, then between the end of the diode not wired to the LC circuit and the terminal of the LC circuit not bearing the diode is wired a ceramic decoupling capacitor. Finally a galvanometer is wired to the terminals of the decoupling capacitor. The device will be sensitive to strong sources of radiowaves at the frequency at which the LC circuit is resonant.

This is given by

When the device is exposed to an RF field which is at the resonant frequency a DC voltage will appear on the terminals on the left hand side. The coil is often outside the case of the unit so it can be brought close to the object being probed.

UHF and SHF

Resonant cavity wavemeter for measuring microwave frequencies in the Ku band
Further information: Ultra high frequency and Super high frequency

At the higher frequencies it is not possible to use lumped components for the tuned circuit. Instead methods such as stripline or resonant cavities are used. One design for ultra high frequencies (UHF) and super high frequencies (SHF) is a resonant λ/4 (quarter wave) rod which can vary in length. Another design for X-band (10 GHz) is a resonant cavity which can be changed in length.

As an alternative for UHF, Lecher transmission lines can be used.[5] It is possible to measure roughly the frequency of a transmitter using Lecher lines.

See also

References

  1. ^ "BRATS - Advanced Amateur Radio Tuition Course". Archived from the original on 2004-08-25. Retrieved 2005-12-23.
  2. ^ "Frequencies Above the Audio Range". Archived from the original on 2006-01-25. Retrieved 2005-12-23.
  3. ^ "Antennas". Archived from the original on 2006-02-08. Retrieved 2005-12-23.
  4. ^ "A Mobile Phone Absorption Wave Meter". www.creative-science.org.uk.
  5. ^ "The Physics of Resonance". www.intuitor.com.

Read other articles:

Manish Dayal

Manish DayalDayal pada Festival Film Internasional Berlin 2017LahirManish PatelOrangeburg, Carolina SelatanPekerjaanAktor, produser Manish Dayal (lahir Manish Patel) adalah aktor film dan televisi serta produser yang dikenal karena perannya sebagai Raj Kher dalam 90210 dan peran utama dalam film The Hundred Foot Journey. Pada saat ini ia berperan sebagai Vijay Nadeer dalam musim 4 dari serial televisi ABC/Marvel Television Agents of S.H.I.E.L.D. Kehidupan awal Dayal terlahir sebagai Manish P...

 

Silvio Berlusconi

Silvio Berlusconi Perdana Menteri ItaliaMasa jabatan8 Mei 2008 – 16 November 2011PresidenGiorgio Napolitano PendahuluRomano ProdiPenggantiMario MontiMasa jabatan11 Juni 2001 – 17 Mei 2006PresidenCarlo Azeglio CiampiWakilGiulio TremontiGianfranco FiniMarco Follini PendahuluGiuliano AmatoPenggantiRomano ProdiMasa jabatan10 Mei 1994 – 17 Januari 1995PresidenOscar Luigi ScalfaroWakilGiuseppe TatarellaRoberto Maroni PendahuluCarlo Azeglio CiampiPenggantiLamberto Di...

 

Daftar Duta Besar Amerika Serikat untuk Mozambik

Duta Besar Amerika Serikat untuk MozambikSegel Kementerian Dalam Negeri Amerika SerikatDicalonkan olehPresiden Amerika SerikatDitunjuk olehPresidendengan nasehat Senat Berikut ini adalah daftar Duta Besar Amerika Serikat untuk Mozambik Daftar Willard Ames De Pree David E. Simcox Peter Jon de Vos Melissa Foelsch Wells Townsend B. Friedman, Jr. Dennis C. Jett Brian D. Curran Sharon P. Wilkinson Helen R. Meagher La Lime William R. Steiger Leslie V. Rowe Douglas M. Griffiths H. Dean Pittman Denni...

Book of the Heavenly Cow

Ancient Egyptian text The sky goddess Nut depicted as a cow and supported by the eight Heh gods Part of a series onAncient Egyptian religion Beliefs Afterlife Cosmology Duat Ma'at Mythology Numerology Philosophy Soul Practices Funerals Offerings: Offering formula Temples Priestess of Hathor Pyramids Deities (list)Ogdoad Amun Amunet Hauhet Heh Kauket Kek Naunet Nu Ennead Atum Geb Isis Nephthys Nut Osiris Set Shu Tefnut A Aati Aker Akhty Amenhotep, son of Hapu Amesemi Ammit Am-heh Amu-Aa Anat A...

 

Prescott, Arizona

Prescott, ArizonaKotaGedung Pengadilan & Patung Buckey O'NeillLocation in Yavapai County and the state of ArizonaCountryUnited StatesStateArizonaCountyYavapaiPemerintahan • JenisCouncil-Manager hisati dultfer • MayorMarlin KuykendallLuas • Kota41,5 sq mi (107,5 km2) • Luas daratan40,1 sq mi (105,4 km2) • Luas perairan0,8 sq mi (2,1 km2)Ketinggian5.368 ft (1.636 m)Populasi...

 

Richard A. Ballinger

American politician (1858–1922) Richard A. Ballinger24th United States Secretary of the InteriorIn officeMarch 6, 1909 – March 12, 1911PresidentWilliam Howard TaftPreceded byJames R. GarfieldSucceeded byWalter L. Fisher31st Commissioner of the General Land OfficeIn officeJanuary 28, 1907 – January 14, 1908PresidentTheodore RooseveltPreceded byWilliam A. RichardsSucceeded byFred Dennett24th Mayor of SeattleIn officeMarch 21, 1904 – March 19, 1906Preceded ...

Druid Hills Presbyterian Church

Church in Georgia, United StatesDruid Hills Presbyterian ChurchDruid Hill Presbyterian Church (2012)Druid Hills Presbyterian ChurchShow map of AtlantaDruid Hills Presbyterian ChurchShow map of GeorgiaDruid Hills Presbyterian ChurchShow map of the United States33°46′27″N 84°21′13″W / 33.77417°N 84.35361°W / 33.77417; -84.35361Location1026 Ponce de Leon AvenueAtlanta, Georgia, United StatesDenominationPresbyterian Church (USA)HistoryFounded1883ArchitectureAr...

 

Tina Thompson

Questa voce sugli argomenti cestisti statunitensi e allenatori di pallacanestro statunitensi è solo un abbozzo. Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Segui i suggerimenti dei progetti di riferimento 1, 2. Tina Thompson Tina Thompson all'All-Star Game WNBA 2013 Nazionalità  Stati Uniti Altezza 188 cm Peso 81 kg Pallacanestro Ruolo Allenatrice (ex ala) Termine carriera 2013 - giocatrice Hall of fame Naismith Hall of Fame (2018)Women's Basketball Hall ...

 

Pablo de Sarasate

Spanish violinist and composer (1844–1908) You can help expand this article with text translated from the corresponding article in Spanish. (November 2023) Click [show] for important translation instructions. View a machine-translated version of the Spanish article. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting...

The Art of the Steal - L'arte del furto

The Art of the Steal - L'arte del furtoKurt Russell in una scena del filmTitolo originaleThe Art of the Steal Lingua originaleinglese Paese di produzioneCanada, Stati Uniti d'America Anno2013 Durata90 min Rapporto2,39:1 Generecommedia, thriller, poliziesco RegiaJonathan Sobol SceneggiaturaJonathan Sobol ProduttoreNicholas Tabarrok Produttore esecutivoJeff Sackman, Mark Slone Casa di produzioneDarius Films Distribuzione in italianoSony Pictures Home Entertainment FotografiaAdam Swi...

 

Manganese germanide

Manganese germanide Structures of left-handed and right-handed MnGe crystals (3 presentations, with different numbers of atoms per unit cell; orange atoms are Ge) Names IUPAC name Manganese germanide Identifiers CAS Number 59125-33-6 3D model (JSmol) Interactive image PubChem CID 57481451 CompTox Dashboard (EPA) DTXSID70851985 InChI InChI=1S/Mn.GeKey: WWFYEXUJLWHZEX-UHFFFAOYSA-N SMILES [Mn].[Ge] Properties Chemical formula MnGe Molar mass 127.57 g/mol Magnetic suscept...

 

List of Alpha Kappa Psi members

This is a list of notable members of Alpha Kappa Psi fraternity. Government U.S. Presidents and Vice Presidents Ronald Reagan was initiated as an honorary member in 1963 by the Alpha Zeta chapter at USC. This preceded his entrance into elected office. Richard Nixon was initiated as an honorary member in 1960 by the Beta Omicron chapter at Wayne State University. He was U.S. vice president at that time. U.S. President Ronald Reagan (1981–1989) (Alpha Zeta '63 Honorary)[1] U.S. Presi...

Springwood Australian Football Club

Australian rules football club Springwood PumasNamesFull nameSpringwood Australian Football ClubNickname(s)PumasClub detailsFounded1972; 52 years ago (1972)Colours   CompetitionQFA Division 1PresidentAndrew HickmanCoachPaul ReyneCaptain(s)Rowan PageGround(s)Lowe OvalUniforms Home The Springwood Pumas Australian Football Club is an Australian rules football club located in Underwood, a suburb of Logan, Queensland. The club emblem is the puma and the team plays in t...

 

Amateur Trapshooting Association

Amateur Trapshooting AssociationJurisdiction InternationalAbbreviationATAFounded1900 (1900) 1940s postcard of headquarters in Ohio The Amateur Trapshooting Association (ATA)[1] serves as the governing body for the sport of American style of trapshooting. The ATA was founded in 1900 and as the American Trapshooting Association.[2] Its first president was John Philip Sousa.[3][4] See also List of shooting sports organizations References ^ The official site o...

 

Busur panah

Busur beralih ke halaman ini. Untuk kegunaan lainnya, lihat Busur (disambiguasi). Seorang pemanah dengan sebuah busur dan kantong berisi anak panah. Busur atau panah atau busur panah dikategorikan sebagai sebuah senjata yang digunakan untuk menembakkan anak panah, dibantu oleh kekuatan elastisitas dari panah itu sendiri. Biasanya senjata ini digunakan untuk berburu dan pada masa lalu sebagai salah satu peralatan perang. Selain itu panah juga digunakan sebagai alat utama dalam olahraga panahan...

Tirúa

Town and Commune in Biobío, ChileTirúaTown and CommuneAerial view of Tirúa Coat of armsMap of the Tirúa commune in the Biobío RegionTirúaLocation in ChileCoordinates (town): 38°20′29″S 73°29′28″W / 38.34139°S 73.49111°W / -38.34139; -73.49111CountryChileRegionBiobíoProvinceAraucoFounded1865Founded asFuerte Tirúa (Fort Tirúa)Government[1][2] • TypeMunicipality • AlcaldeJosé Aniñir Lepicheo (RN)Area[3...

 

2014 European Athletics Championships – Men's 110 metres hurdles

2014 EuropeanAthletics ChampionshipsTrack events100 mmenwomen200 mmenwomen400 mmenwomen800 mmenwomen1500 mmenwomen5000 mmenwomen10,000 mmenwomen100 m hurdleswomen110 m hurdlesmen400 m hurdlesmenwomen3000 msteeplechasemenwomen4 × 100 m relaymenwomen4 × 400 m relaymenwomenRoad eventsMarathonmenwomenMarathon teammenwomen20 km walkmenwomen50 km walkmenField eventsHigh jumpmenwomenPole vaultmenwomenLong jumpmenwomenTriple jumpmenwomenShot putmenwomenDiscus throwmenwomenHammer throwmenwomenJavel...

 

Eastside Historic Cemetery District

Historic district in Michigan, United States United States historic placeEastside Historic Cemetery DistrictU.S. National Register of Historic PlacesU.S. Historic district Mount Elliott Cemetery front gate, built 1882Interactive mapLocationDetroit, Michigan, U.S.Coordinates42°20′59″N 83°1′5″W / 42.34972°N 83.01806°W / 42.34972; -83.01806Built1841NRHP reference No.82000550[1]Added to NRHPDecember 2, 1982 The Eastside Historic Cemetery Distr...

日本ソフトボール協会

公益財団法人日本ソフトボール協会Japan Softball Association 事務所があるJAPAN SPORT OLYMPIC SQUARE団体種類 公益財団法人設立 1949年所在地 東京都新宿区霞ヶ丘町4-2JAPAN SPORT OLYMPIC SQUARE法人番号 2011005003761 主要人物 会長 牧島かれん副会長 宇津木妙子活動地域 日本主眼 日本におけるソフトボール界を統轄し代表する団体としてソフトボールの普及および振興を図り、もって国民の�...

 

Черепахин, Борис Борисович

В Википедии есть статьи о других людях с фамилией Черепахин. Борис Борисович Черепахин Дата рождения 17 (29) ноября 1894(1894-11-29) Место рождения село Белокриница, Кременецкий уезд, Волынская губерния, Российская империя Дата смерти 27 августа 1969(1969-08-27) (74 года) Место смерти �...