Tuner Section.pptx

8/18/2019 Tuner Section.pptx

1/26

Chapter 6 THE TUNER SECTION OF THE SUPERHERODYNERADIO RECEIVER


2/26

the tuner section is locate at the !ront"en or at the place #here the si$nals enter theraio recei%er&

For clarit'( the ter) superhetero'ne raio recei%er( raio recei%er( an transistor raiorecei%er( ha%e the sa)e )eanin$& So either o! these ter)s can *e use in our iscussions&

No#( the tuner section has the !ollo#in$ i)portant !unctions&

+& it intercepts an collects the raio si$nals !ro) the raio trans)ittin$ or *roacastin$stations&,& it selects #hich o! the collecte raio si$nal shoul enter the raiio recei%er&-& it con%erts the !re.uenc' o! the selecte raio si$nal to its inter)eiate !re.uenc'si$nal e.ui%alent&

To per!or) the a*o%e !uctions( the tuner section as the !ollo#in$ parts&


3/26

Fig.44 Pictorial appearances of the Importants parts in the tuner section.

As sho#n in Fi$s&/- an //( the i)portant parts in the tuner section are(

+& Antenna,& Tunnin$ capacitor or conenser

-& 0ocal coil/& 1i2er3con%erter transistorFor our *ene4t( #e #ill stu' the !unction or #or5 o! each parts( their *asic contructionan connections&

Antenna. asicall' the antenna se in transistor raios are )ae o! t#o coils o! %er' thin#ires& These thin #ires are #oun aroun the po#ere iron core& This po#ere thin core is

also calle antenna *ar or !errite core&


4/26

Fi$& /6 Pictorial appearance o! the antenna

Pri)ar' an Seconar' 7inin$s o! the Antenna& As #e ha%e sai( the antenna is )ae up o!

t#o coils o! thin #ires( One o! these coils is calle the pri)ar' #inin$& An the other coil iscalle the seconar' #inin$& Althou$h *oth the pri)ar' an seconar' are #oun in one core orantenna *ar( 'et these t#o coils are not connecte to each other& This is coil *ecause each coil iscoate co)pletel' #ith an insulator such as shellac etc& You )a' as5( o the coils an theantenna *ar ha%e electrical connection8 No( the coils an the antenna *ar ha%e no electricalconnection& Althou$h the coils an the antenna *ar ha%e ph'sical connection 'et current that9o#s in the coils oes not 9o# in the antenna *ar *ecause the coils are coate #ith an insulator&:See Fi$s& /; an /6


5/26

Funtion or Work of the Antenna. in the tuner section( it is the antenna that interceptsan collects the raio si$nals that co)es !ro) the raio *roacastin$ startions&

How the Antenna Intercepts The Radio Signals. 7hen the tra%ellin$ raio si$nals or electro)a$netic #a%es hit the antenna( inuce %olta$e an inuce current are p rouce in the sai antenna This current prouce *' inuce %olta$e is oscillatin$ or is 9o#in$ *ac5 an !orth in the in the antenna& As this current 9o#s *ac5 an !orth( electro)a$netic lines o! !orce are prouce in the pri)ar' #inin$ o! the antenna& This electro)a$netic lines o! !orces lin5 the pri)ar' an seconar'#inin$s o! the antenna& :see Fi$ /=<


6/26

Fi$&/= The electro)a$netic lines o! !orce lin5s the

pri)ar' #inin$an the seconar' #inin$ o! the antenna ecause current that prouces the electro)a$netic lines o! !orces is9o#in$ *ac5 an !orth or is oscillatin$(the irections o! the 9o# o! the

electro)a$netic lines o! !orce also %aries in step #ith the oscillations o! thesai current&in other #ors the electro)a$netic lines o! !orce prouce *' theoscillatin$ current are )o%in$ as the' chan$e irections&:See :Fi$s&/= an /><

In as )uch as the electro)a$netic lines o! !orce that lin5 the pri)ar' anseconar' #inin$s are )o%in$s( the sai lines o! !orce are e?ecti%el'penetratin$ an cuttin$ throu$h the coil #inin$s o! the pri)ar' an

seconar'ith this action(inuce current is prouce in the seconar'#inin$&No#(in as )uch as the oscillatin$ current in the pri)ar' #inin$ is

prouce *' the raio si$nal that is intercepte *' the antenna&the %ariations

or the !re.uenc' o! the oscillatin$ current as #ell as its electro)a$netic lineso! !orce is e2actl' the sa)e as the !re.uenc' o! the intercepte raio si$nal&An *ecause the inuce current in the seconar' #inin$ is prouce *' the

electro)a$netic line o! !orce !ro) the pri)ar' #inin$(so the !re.uenc' or%ariation o! the seconar' inuce inuce current is e2actl'

the sa)e as the raio si$nal that is intercepte an collecte *' the antenna&


7/26


8/26


9/26

Fi2e *ea) In this beam, bothends of the beam

are rigidly fixedinto the supports.

Also, Main

reinforcement bars

and stirrups areprovided.


10/26

Cantile%er *ea) It is fixed in a wallor column at one

end and the other

end is free, it iscalled cantilever

beam. It has

tension zone in

the top side andcompression zone

in the bottom side


11/26

Continuous *ea) It is supportedon more than

two supports .

This beam ismore

economical

for any span

lengths.


12/26

O%erhan$in$ *ea) In overhanging

beam, Its end

extends beyond the

wall or column

support.

Overhanging of the

beam is the

unsupportedportion of the beam.

It may be one side

or both the sides of

the support.


13/26

R&C&C& ea)s

ingly !einforced "eam

#oubly !einforced "eam


14/26

T'pes o! 0oain$ on

ea)s $oncentrated %oad

&niformly #istributed %oads &niformly 'arying %oads Arbitrary %oading


15/26


16/26

CO0U1NS$olumn is a vertical structural

member. It transmits the load from

ceiling(roof slab and beam, includingits self)weight to the foundation.

$olumns may be sub*ected to a pure

compressive load. !.$.$. columns arethe most widely used now)a)days.


17/26

T'pes o! Colu)ns

%ong $olumn Or lender hort $olumn Intermediate $olumn


18/26


19/26

Pr@cautions o! Colu)ns

construction

rocess of construction

'ertical -eight of concrete $olumns for more then one storey %oad on the column of the top storey


20/26

Steel Colu)ns or

Stanchions tandard tructural teel ections


21/26

"uild)up $olumn ections


22/26

0INTE0S

%intel is a short beam with its ends

built into a wall. It is a horizontal

structural member placed over smallopenings of the wall for door, window,

ventilator, cupboard, etc.


23/26

C0ASSIFICATION

OF 0INTE0S

Timber %intel

tone %intel "ric %intels teel %intels

!.$.$. %intels


24/26

R&C&C& 0intel O%er Inteior

Door Openin$


25/26

E?ecti%e 0oa On 0intel


26/26

PRS!T" #

SA01AN HAN

ARUN

Thank ou

Documents

Tuner Section.pptx