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50-540: CHFI-FM has an effective radiated power (ERP) of 44,000 watts . The transmitter is atop the CN Tower . The station first signed on the air on February 1, 1957. It was initially owned by CHFI-FM, Ltd. CHFI was the first commercial FM outlet in Toronto to provide its own distinct programming rather than simulcasting an AM station. The call sign chosen to represent the words " C anada H i FI " or " high fidelity ", providing

100-581: A soft adult contemporary format. The transition worked, making CHFI one of the longest-running English-language adult contemporary stations in Canada . In December 1987, Don Daynard became CHFI's new morning show host, a position he would hold until his retirement on December 10, 1999. Erin Davis joined the morning show in September 1988, with "Don and Erin" becoming one of Toronto's most prominent morning shows through

150-497: A waiver , and can exceed normal restrictions. For most microwave systems, a completely non-directional isotropic antenna (one which radiates equally and perfectly well in every direction – a physical impossibility) is used as a reference antenna, and then one speaks of EIRP (effective isotropic radiated power) rather than ERP. This includes satellite transponders , radar, and other systems which use microwave dishes and reflectors rather than dipole-style antennas. In

200-622: A cellular telephone tower has a fixed linear polarization, but the mobile handset must function well at any arbitrary orientation. Therefore, a handset design might provide dual polarization receive on the handset so that captured energy is maximized regardless of orientation, or the designer might use a circularly polarized antenna and account for the extra 3 dB of loss with amplification. For example, an FM radio station which advertises that it has 100,000 watts of power actually has 100,000 watts ERP, and not an actual 100,000-watt transmitter. The transmitter power output (TPO) of such

250-464: A gain of 1× (equiv. 0 dBi). So ERP and EIRP are measures of radiated power that can compare different combinations of transmitters and antennas on an equal basis. In spite of the names, ERP and EIRP do not measure transmitter power, or total power radiated by the antenna, they are just a measure of signal strength along the main lobe. They give no information about power radiated in other directions, or total power. ERP and EIRP are always greater than

300-420: A higher quality sound than on AM radio . CHFI also initially provided a special Muzak -like background audio service, playing soft instrumental music for offices and retail outlets in the city. The station was acquired in 1960 by Aldred-Rogers Broadcasting, a forerunner to Rogers Radio . In 1962, an AM counterpart, CHFI (1540 AM) was added, which originally simulcast CHFI-FM's programming. CHFI-FM pioneered

350-432: A number of the station's much-imitated programs. The most famous was the popular and long running Candlelight and Wine heard evenings from 6 to 11 p.m. The program, hosted by Don Parrish, mixed soothing instrumentals, soft vocals and occasional light classical pieces in " pop " arrangements. The program spun off a series of best-selling record albums, many of which are now highly prized collectors' items. Compeau also created

400-423: A station typically may be 10,000–20,000 watts, with a gain factor of 5–10× (5–10×, or 7–10  dB ). In most antenna designs, gain is realized primarily by concentrating power toward the horizontal plane and suppressing it at upward and downward angles, through the use of phased arrays of antenna elements. The distribution of power versus elevation angle is known as the vertical pattern . When an antenna

450-886: A theoretical isotropic antenna. Since a half-wave dipole antenna has a gain of 1.64 (or 2.15 dB ) compared to an isotropic radiator, if ERP and EIRP are expressed in watts their relation is   E I R P ( W ) = 1.64 × E R P ( W )   {\displaystyle \ {\mathsf {EIRP}}_{\mathsf {(W)}}=1.64\times {\mathsf {ERP}}_{\mathsf {(W)}}\ } If they are expressed in decibels   E I R P ( d B ) = E R P ( d B ) + 2.15   d B   {\displaystyle \ {\mathsf {EIRP}}_{\mathrm {(dB)} }={\mathsf {ERP}}_{\mathrm {(dB)} }+2.15\ {\mathsf {dB}}\ } Effective radiated power and effective isotropic radiated power both measure

500-983: Is   E I R P ( d B W ) = P T X   ( d B W ) − L ( d B ) + G ( d B i )   , {\displaystyle \ {\mathsf {EIRP}}_{\mathsf {(dB_{W})}}=P_{{\mathsf {TX}}\ {\mathsf {(dB_{W})}}}-L_{\mathsf {(dB)}}+G_{\mathsf {(dB_{i})}}\ ,}   E R P ( d B W ) = P T X   ( d B W ) − L ( d B ) + G ( d B i ) − 2.15   d B   . {\displaystyle \ {\mathsf {ERP}}_{\mathsf {(dB_{W})}}=P_{{\mathsf {TX}}\ {\mathsf {(dB_{W})}}}-L_{\mathsf {(dB)}}+G_{\mathsf {(dB_{i})}}-2.15\ {\mathsf {dB}}~.} Losses in

550-402: Is 8.77 dB d = 10.92 dB i . Its gain necessarily must be less than this by the factor η, which must be negative in units of dB. Neither ERP nor EIRP can be calculated without knowledge of the power accepted by the antenna, i.e., it is not correct to use units of dB d or dB i with ERP and EIRP. Let us assume a 100 watt (20 dB W ) transmitter with losses of 6 dB prior to

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600-422: Is a constant, i.e., 0 dB d = 2.15 dB i . Therefore, ERP is always 2.15 dB less than EIRP. The ideal dipole antenna could be further replaced by an isotropic radiator (a purely mathematical device which cannot exist in the real world), and the receiver cannot know the difference so long as the input power is increased by 2.15 dB. The distinction between dB d and dB i is often left unstated and

650-538: Is also directional horizontally, gain and ERP will vary with azimuth ( compass direction). Rather than the average power over all directions, it is the apparent power in the direction of the peak of the antenna's main lobe that is quoted as a station's ERP (this statement is just another way of stating the definition of ERP). This is particularly applicable to the huge ERPs reported for shortwave broadcasting stations, which use very narrow beam widths to get their signals across continents and oceans. ERP for FM radio in

700-411: Is an IEEE standardized definition of directional radio frequency (RF) power, such as that emitted by a radio transmitter . It is the total power in watts that would have to be radiated by a half-wave dipole antenna to give the same radiation intensity (signal strength or power flux density in watts per square meter) as the actual source antenna at a distant receiver located in the direction of

750-406: Is larger it will be used instead. The maximum ERP for US FM broadcasting is usually 100,000 watts (FM Zone II) or 50,000 watts (in the generally more densely populated Zones I and I-A), though exact restrictions vary depending on the class of license and the antenna height above average terrain (HAAT). Some stations have been grandfathered in or, very infrequently, been given

800-438: Is quantified by the antenna gain , which is the ratio of the signal strength radiated by an antenna in its direction of maximum radiation to that radiated by a standard antenna. For example, a 1,000 watt transmitter feeding an antenna with a gain of 4× (equiv. 6 dBi) will have the same signal strength in the direction of its main lobe, and thus the same ERP and EIRP, as a 4,000 watt transmitter feeding an antenna with

850-475: Is the same as ERP, except that a short vertical antenna (i.e. a short monopole ) is used as the reference antenna instead of a half-wave dipole . Cymomotive force ( CMF ) is an alternative term used for expressing radiation intensity in volts , particularly at the lower frequencies. It is used in Australian legislation regulating AM broadcasting services, which describes it as: "for a transmitter, [it] means

900-448: Is typical for medium or longwave broadcasting, skywave , or indirect paths play a part in transmission, the waves will suffer additional attenuation which depends on the terrain between the antennas, so these formulas are not valid. Because ERP is calculated as antenna gain (in a given direction) as compared with the maximum directivity of a half-wave dipole antenna , it creates a mathematically virtual effective dipole antenna oriented in

950-486: Is usually connected to the antenna through a transmission line and impedance matching network . Since these components may have significant losses   L   , {\displaystyle \ L\ ,} the power applied to the antenna is usually less than the output power of the transmitter   P T X   . {\displaystyle \ P_{\mathsf {TX}}~.} The relation of ERP and EIRP to transmitter output power

1000-414: The station identification . In addition, newer jingles were unveiled, along with an opening bumper for newer music. As well, some upbeat, rhythmic material was also added, while softer artists such as Air Supply were largely dropped from the station's playlist. On December 26, 2009, long-time competitor CJEZ switched from an adult contemporary format to an adult hits format as CHBM-FM , leaving CHFI as

1050-535: The " beautiful music " format in Canada. The main programming heard from dawn until midnight was traditional easy listening fare, mostly instrumental cover versions of popular hits, as well as Broadway and Hollywood show tunes. In 1972, CHFI's AM sister station, by this point under the CFTR call letters, abandoned the beautiful music simulcast of CHFI-FM and adopted a Top 40 format. Music director Michael Compeau created

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1100-519: The 1990s. Bob Magee took over Daynard's position on December 13, 1999. A new logo was unveiled in 2000 , when Rogers rebranded the station from CHFI FM98 and the "Toronto's Perfect Music Mix" slogan, to 98.1 CHFI , moving away from soft adult contemporary to mainstream AC under the "Toronto's Soft Rock" slogan. In June 2003 , CHFI, competing closely with rival adult contemporary station CJEZ, revamped their morning show to attract younger listeners. Firing Erin Davis and moving Bob Magee to afternoons,

1150-1191: The EIRP or ERP. Since an isotropic antenna radiates equal power flux density over a sphere centered on the antenna, and the area of a sphere with radius   r   {\displaystyle \ r\ } is   A = 4 π   r 2   {\displaystyle \ A=4\pi \ r^{2}\ } then   S ( r ) =   E I R P     4 π   r 2     . {\displaystyle \ S(r)={\frac {\ {\mathsf {EIRP}}\ }{\ 4\pi \ r^{2}\ }}~.} Since   E I R P = E R P × 1.64   , {\displaystyle \ \mathrm {EIRP} =\mathrm {ERP} \times 1.64\ ,}   S ( r ) =   0.410 × E R P     π   r 2     . {\displaystyle \ S(r)={\frac {\ 0.410\times {\mathsf {ERP}}\ }{\ \pi \ r^{2}\ }}~.} After dividing out

1200-619: The FCC database shows the station's transmitter power output, not ERP. According to the Institution of Electrical Engineers (UK), ERP is often used as a general reference term for radiated power, but strictly speaking should only be used when the antenna is a half-wave dipole, and is used when referring to FM transmission. Effective monopole radiated power ( EMRP ) may be used in Europe, particularly in relation to medium wave broadcasting antennas. This

1250-498: The Sunday morning program The Feel Good Brunch , which will also air on other adult contemporary radio stations owned by Rogers across Canada. In March, it was announced that former MuchMusic VJ Rick Campanelli was joining the station as a weekday afternoon host. CHFI-FM can also be heard on these low-power transmitters: Effective radiated power Effective radiated power ( ERP ), synonymous with equivalent radiated power ,

1300-539: The United States is always relative to a theoretical reference half-wave dipole antenna. (That is, when calculating ERP, the most direct approach is to work with antenna gain in dB d ). To deal with antenna polarization, the Federal Communications Commission (FCC) lists ERP in both the horizontal and vertical measurements for FM and TV. Horizontal is the standard for both, but if the vertical ERP

1350-428: The actual total power radiated by the antenna. The difference between ERP and EIRP is that antenna gain has traditionally been measured in two different units, comparing the antenna to two different standard antennas; an isotropic antenna and a half-wave dipole antenna: In contrast to an isotropic antenna, the dipole has a "donut-shaped" radiation pattern, its radiated power is maximum in directions perpendicular to

1400-426: The antenna itself are included in the gain. If the signal path is in free space ( line-of-sight propagation with no multipath ) the signal strength ( power flux density in watts per square meter)   S   {\displaystyle \ S\ } of the radio signal on the main lobe axis at any particular distance r {\displaystyle r} from the antenna can be calculated from

1450-505: The antenna's strongest beam ( main lobe ). ERP measures the combination of the power emitted by the transmitter and the ability of the antenna to direct that power in a given direction. It is equal to the input power to the antenna multiplied by the gain of the antenna. It is used in electronics and telecommunications , particularly in broadcasting to quantify the apparent power of a broadcasting station experienced by listeners in its reception area. An alternate parameter that measures

1500-1002: The antenna, declining to zero on the antenna axis. Since the radiation of the dipole is concentrated in horizontal directions, the gain of a half-wave dipole is greater than that of an isotropic antenna. The isotropic gain of a half-wave dipole is 1.64, or in decibels   10   log 10 ⁡ ( 1.64 ) = 2.15   d B   , {\displaystyle \ 10\ \log _{10}(1.64)=2.15\ {\mathsf {dB}}\ ,} so   G i = 1.64   G d   . {\displaystyle \ G_{\mathsf {i}}=1.64\ G_{\mathsf {d}}~.} In decibels   G ( d B i ) = G ( d B d ) + 2.15   d B   . {\displaystyle \ G_{\mathsf {(dB_{i})}}=G_{\mathsf {(dB_{d})}}+2.15\ {\mathsf {dB}}~.} The two measures EIRP and ERP are based on

1550-426: The antenna. ERP < 22.77 dB W and EIRP < 24.92 dB W , both less than ideal by η in dB. Assuming that the receiver is in the first side-lobe of the transmitting antenna, and each value is further reduced by 7.2 dB, which is the decrease in directivity from the main to side-lobe of a Yagi–Uda. Therefore, anywhere along the side-lobe direction from this transmitter, a blind receiver could not tell

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1600-568: The case of medium wave (AM) stations in the United States , power limits are set to the actual transmitter power output, and ERP is not used in normal calculations. Omnidirectional antennas used by a number of stations radiate the signal equally in all horizontal directions. Directional arrays are used to protect co- or adjacent channel stations, usually at night, but some run directionally continuously. While antenna efficiency and ground conductivity are taken into account when designing such an array,

1650-403: The difference if a Yagi–Uda was replaced with either an ideal dipole (oriented towards the receiver) or an isotropic radiator with antenna input power increased by 1.57 dB. Polarization has not been taken into account so far, but it must be properly clarified. When considering the dipole radiator previously we assumed that it was perfectly aligned with the receiver. Now assume, however, that

1700-473: The direction of the receiver. In other words, a notional receiver in a given direction from the transmitter would receive the same power if the source were replaced with an ideal dipole oriented with maximum directivity and matched polarization towards the receiver and with an antenna input power equal to the ERP. The receiver would not be able to determine a difference. Maximum directivity of an ideal half-wave dipole

1750-434: The factor of   π   , {\displaystyle \ \pi \ ,} we get:   S ( r ) =   0.131 × E R P     r 2     . {\displaystyle \ S(r)={\frac {\ 0.131\times {\mathsf {ERP}}\ }{\ r^{2}\ }}~.} However, if the radio waves travel by ground wave as

1800-414: The modern recordings were phased out and the program featured mainly the period recordings. By the mid-1980s, the audience for CHFI and other beautiful music stations was beginning to age, while advertisers usually seek younger listeners. This led to the elimination of the specialty programs coupled with more vocals in the playlist . Eventually, CHFI eliminated nearly all instrumental music, and instituted

1850-644: The only adult contemporary station in Toronto. In late 2015, Mike Cooper announced his retirement, though would continue to host the classic hits -formatted "Coop's Classics" on Saturday nights. Darren B. Lamb, formerly with CHUM-FM , joined CHFI as Davis' co-host in February 2016. On November 9, 2016, Erin Davis announced she would be retiring from CHFI on December 15, and would be moving to British Columbia to be closer to her family. Lamb continued to host mornings, along with new co-host Maureen Holloway . On October 1, 2021, Maureen Holloway announced she would be leaving

1900-430: The popular Classics 'til Dawn , an overnight program of popular classical music . (In 1984, Compeau would become program director of classical station CFMX-FM and use this same format for its overnight program.) Another of Compeau's innovations was Front Row Centre , heard Sunday afternoons at 2 p.m. This one-hour program featured full original cast recordings of popular Broadway musicals, with host Don Parish explaining

1950-428: The power density a radio transmitter and antenna (or other source of electromagnetic waves) radiate in a specific direction: in the direction of maximum signal strength (the " main lobe ") of its radiation pattern. This apparent power is dependent on two factors: The total power output and the radiation pattern of the antenna – how much of that power is radiated in the direction of maximal intensity. The latter factor

2000-441: The product, expressed in volts, of: It relates to AM broadcasting only, and expresses the field strength in " microvolts per metre at a distance of 1 kilometre from the transmitting antenna". The height above average terrain for VHF and higher frequencies is extremely important when considering ERP, as the signal coverage ( broadcast range ) produced by a given ERP dramatically increases with antenna height. Because of this, it

2050-433: The radio station. The records were cleaned, repaired and brushed with distilled water before being transcribed to tape. Dubbed the "new library of old 78's", these antique rarities were showcased each weeknight. (In 1974, host Todd Russell died and was replaced by Sandy Hoyt.) CHFI soon amassed a collection of over 3,500 period recordings and the reminiscing program became one of the station's biggest successes. As time went on,

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2100-449: The reader is sometimes forced to infer which was used. For example, a Yagi–Uda antenna is constructed from several dipoles arranged at precise intervals to create greater energy focusing (directivity) than a simple dipole. Since it is constructed from dipoles, often its antenna gain is expressed in dB d , but listed only as dB. This ambiguity is undesirable with respect to engineering specifications. A Yagi–Uda antenna's maximum directivity

2150-464: The receiving antenna is circularly polarized, and there will be a minimum 3 dB polarization loss regardless of antenna orientation. If the receiver is also a dipole, it is possible to align it orthogonally to the transmitter such that theoretically zero energy is received. However, this polarization loss is not accounted for in the calculation of ERP or EIRP. Rather, the receiving system designer must account for this loss as appropriate. For example,

2200-442: The same thing is effective isotropic radiated power ( EIRP ). Effective isotropic radiated power is the hypothetical power that would have to be radiated by an isotropic antenna to give the same ("equivalent") signal strength as the actual source antenna in the direction of the antenna's strongest beam. The difference between EIRP and ERP is that ERP compares the actual antenna to a half-wave dipole antenna, while EIRP compares it to

2250-423: The same time, the station returned to using the point on the station's ID, returned to its soft AC format, and switched its slogan to "Toronto's Lite Favourites." This turned around CHFI's popularity, as the station reclaimed the top spot in the Toronto ratings, while CJEZ's ratings fell. In 2009 , CHFI returned to mainstream AC, but retained the "Toronto's Lite Favourites" slogan and added the decimal point back in

2300-440: The station named Mad Dog and Billie, later known as "Jay and Billie", as the morning team, beginning June 23. Jay and Billie hosted mornings on co-owned Toronto station CISS-FM before it flipped to adult hits earlier that month. In addition, the station rebranded as 98.1 CHFI (pronounced, "ninety-eight-one CHFI") instead, and unveiled the "Today's Lite Music" slogan. Bringing Jay and Billie on for mornings backfired on CHFI, as

2350-439: The station's ratings declined. In September 2004, Erin Davis was hired by CJEZ as a fill-in co-host, working alongside Mike Cooper. This brought CJEZ's ratings up dramatically, beating CHFI in several target audience demographics. In June 2005, CHFI management fired Jay and Billie, rehired Davis for mornings (who returned on September 6), and also hired Mike Cooper as her co-host on October 26 after his contract with CJEZ expired. At

2400-491: The station, with Lamb having had his last appearance earlier in the year (Lamb has since retired). The following week, Tracy Moore from co-owned television station CITY-TV began hosting the show on a temporary basis. On November 29, CHFI announced that Pooja Handa and Gurdeep Ahluwalia, formerly of CP24 , would begin hosting mornings on January 4, 2022. In January 2024, several months after joining Rogers as co-host of Breakfast Television on Citytv, Meredith Shaw launched

2450-432: The story between songs. In the 1970s, Todd Russell began hosting a late evening program called Reminiscing featuring modern recordings of popular songs from the 1920s, 1930s, 1940s and 1950s. In 1973, Compeau decided to add some spice to the program by sprinkling in a few original period recordings. Since very few had been reissued on LP at this time, a call went out to collectors who loaned their original 78-rpm records to

2500-789: The two different standard antennas above: Since the two definitions of gain only differ by a constant factor, so do ERP and EIRP   E I R P ( W ) = 1.64 × E R P ( W )   . {\displaystyle \ {\mathsf {EIRP}}_{\mathsf {(W)}}=1.64\times {\mathsf {ERP}}_{\mathsf {(W)}}~.} In decibels   E I R P ( d B W ) = E R P ( d B W ) + 2.15   d B   . {\displaystyle \ {\mathsf {EIRP}}_{\mathsf {(dB_{W})}}={\mathsf {ERP}}_{\mathsf {(dB_{W})}}+2.15\ {\mathsf {dB}}~.} The transmitter

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