Help Me : Building an FM Antenna for My home receiver

[navino87]

Hi guys...

Please help me reg. Building an FM Antenna for my home receiver...
Iam doing my MBA @ VIT (Staying out in a rental house with friends). Here my pass time is computer n my audio system... Unfortunately I dont get clear fm signals @ my room. So iam planning to build a FM Antenna...

But unfortunately I dont know anything on it... So please help me out guys...

Thanks in advance..

[desai_amogh]

try this link
http://www.willus.com/author/antenna.shtml

u have to change the frquency from 88.5 MHz to the frequency u want to receive. for example 98.3 Mhz for radio mirchi

u can try this !!

http://www.weru.org/reception.html

http://www.geocities.com/zbtaz/

[navino87]

Originally Posted by desai_amogh

try this link
http://www.willus.com/author/antenna.shtml

u have to change the frquency from 88.5 MHz to the frequency u want to receive. for example 98.3 Mhz for radio mirchi

u can try this !!

http://www.weru.org/reception.html

http://www.geocities.com/zbtaz/

Thanks a lot man...

As i dont hav much knowledge about this everything seems to be complicated... Can some1 explain me with some simple steps???

[abhasbajpai]

the most simple solution is to use yagi antenna
the same one you use for tv reception
connect it with antenna cable and the connect it to you receiver
without that 75 ohm impidence balloon.

[navino87]

^^ wat is 75 ohm impidence balloon???

I hav seen an old tv antenna @ top of my house( The antenna looks like the pic i attached bellow) , n i some how managed to attach a pair of twisted electric wire to it.. now, i attached the other end of the two wire to my player's antenna...

Unfortunately after doing all this i dont get fm signal instead getting something else(think it is DD channels )... Wat 2 do???

Image of TV antenna

[abhasbajpai]

were you have connected the wire, the wire should be connected to the wires were the antenna should be, or you twist the wires and knot it around the antenna and then tune the receiver,

[navino87]

I have connected one end of the wire to the to one end of the bended pipe in the antenna n other to the other end...

BTW the antenna does't seems 2 be in good condition... its rusted, broken(but i joined it using an tape ) etc... Will it be a problem???

Thanks

[abhasbajpai]

you have to connect the wires to both ends of dipole, which is kind a u shape tube on the antenna, then the other wire to the your reciver were your antenna wires are connected or you can twist the wires and attach to the antenna of the receiver.

[navino87]

"twist the wires and attach to the antenna of the receiver" in the sence tat should the wire be twisted fully on the antenna of the receiver???

wat i done is , taken the insulation of the wire to litle extent(1inch or 2) n twisted it to the antenna of the receiver...

[desai_amogh]

read this ull understand evrything: http://www.kyes.com/antenna/antennadex.html

OR if r not a learner then do this >>>>


Using a Di-Pole Antenna

Di-poles are T-shaped wire antennas made for indoor use. You can buy them in radio supply stores, and they are inexpensive.

Attach the bottom leg of the T to the antenna terminals of your radio (experiment while attaching) and then play with the location of the T. The placement of the T is critical to the performance of the di-pole.

If you are really bold, or crave WERU reception on a budget, you can make a custom di-pole. The advantage is that you can greatly increase a di-pole’s effectiveness by its size and/or placement outside! You’ll need some of the twin lead cable we mentioned earlier.

The custom di-pole you make will be a T just like the ready-made you might buy, except you’ll be able to tailor it to your needs. However, you need to abide by these, or multiples of these, dimensions; the top bar should be 5'1" or 10'2" or 15'3" or 20'4", etc. and the bottom leg must connect at the middle of that top bar (2'6", etc.) You can drape custom di-pole over the roof of your house, or climb the tree in your front yard and tie it to the appropriate branches (of course, experimenting tirelessly to find the proper orientation of the di-pole for best reception). Twin lead is so cheap that you may find yourself quite proud of the dramatic improvement in reception for a bit of time, but very little money. However, don’t kid yourself about the effectiveness of a custom di-pole versus a traditional metal TV/FM antenna.

Cut an appropriate length of twin for the top bar. In the middle of that length cut one of the two conductors and strip back the plastic coating. Now connect another length of the twin lead to the two bare conductors of the top bar. The other end is connected to your radio antenna terminals.

If a custom di-pole sounds like too much trouble, you can make a cut-and-split di-pole. Take some twin lead and split it down the middle. Attach the other end to the radio. Very simple, though not as effective as the custom di-pole.



if u dint understand this then do this >>

go to a electric motor/mixer/fan winding shop >> ask him for a 20-22 gauge coper wire (if he asks for a explanation tell him u want a single strand copper wire without insulation (earthing wire as it is called at times) ..)

& u can use this cable to build ur antenna.

i feel this is the best option:
http://www.willus.com/author/antenna.shtml

[iMav]

arre jus tie 1 end a normal copper wire(insulated) and take the other end of the window that shall do the trick

[desai_amogh]

herez what u gt to do


1st ull have to 1st calculate the length of the cnducators for the antenna..


decide what is going to be ur primary radio station >>

for eg i listen to Radio mirchi at 98.3MHz so i need to design my antenna for 98.3 Mhz..
so the calculation for lenght of the antenna is:

wavelenght of the fm frequency / (divide by) 4 = 1.18x 10raise to 10 / (divide by 98.3 x 10 raise to 6)

wavelength is calc by dividing the speed of light by the frequency of the fm signal.. thts all noted on thlink i have given u..

so in my case it comes to 1.18x 10raise to 10 / 98.3 x 10raiseto 6 (frq in Hz)
------------------------------------------------
divide by 4


in my case for 98.3 the length comes to approx 35.42 & in the link i have given u he used the 88.5 frequency & he got the length as 33.34

so now u if u too want to listen to radio mirchi @ 98.3 fm then get the copper wire i mentioned above cut it into 2 equal parts of 35.42 inches
stick it to the wall harizontally like this:

==================a b==================
. .............35.42 inches | | 35.42 inches
. ...............................| |
............................... .| |
............................... .c d
connect a good quality wire to 'a' & 'b' .. the other ends of the wire i.e.
'c' goes to the antenna & 'd' goes to the -ve of the battery connector(or the power supply)
this shud surely give u better signals.. now u can adjust the atenna for better position .. i mean right now u have it stuck on the wall horizontally u can move it 360 degrees >>>> & find the angle where u get best reception >>> & stick it to ur wall to the best angle.

IMP: dont forget to ignore those crazy looking dots in there .. they dont let us put spaces in here..& i im bored to attach a picture ...

btw do u get fm channels in heaven ??