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How to connect Tv and Radio to same Antenna?

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Analyzer

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Hi there,

I have a TFT Tv and car radio in my car and i would like connect both of them to same antenna but i don't know if i should notice specific info.

Thanks in advance.

Analyzer.
 

Hishamsaleh

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to find out what antenna is working for any system you need at leest to know on what frequency band you are working.

then apply this:

minimum antenna length = (0.1)*(3*10^8)/frequency.
Maximum antenna length = (0.5)*(3*10^8)/frequency.

for example...
for UHF TV channels you have a frequency band (470 - 812 MHz)...
-minimum antenna lengh is between 0.06 m - 0.036 m. So it's 0.06m
-Maximumantenna lengh is between 0.3 m - 0.18 m. So it's 0.18m

so do the same for radio waves... if antenna length is included you can connect it directly to the antenna...

NOTE: minimum and maximum is for optimum use... while you can use ather lengths.
 

Hishamsaleh

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frequency spectrum

you can use this to calc

ya analyzer... you can connect both devices to the same antenna coz mainly you need the same kind of antenna and almost the same length range.
 

Borber

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You should use frequency splitter to separate FM band 87.5MHz-108MHz and VHF-HF band fron 175MHz above. It can be done by connecting low-pass and high-pass filters togrther to antenna and output of filters to receivers.
It looks something like this:
 

sda

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Hi
I think you'll have to give us more info on the aerial you have already installed in your car.
If it is a telescopic type or a closed dipole on the windscreen.
But in any case, your best option is to install an extra one for TV, for decent reception, which will include some sort of preamp.

cheers
sda
 

flatulent

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legal problems

In many countries having a TV set that can be seen by the driver is illegal. Be careful where you mount your set.
 

Element7k

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Hi,
I have noticed in the new Volvo estates that all in one side window printed antennas are used receive AM/FM + TV antennas. Very simple forked shaped antennas for FM/AM and V-shaped for TV. Anyone know how these are designed?

Cheers,
Element7k
 

Analyzer

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Hi,

Thank you for your kind replies for my problem.I think i need to reply answers.

@Borber :

Your schematic is very interesting i will try it but i need to ask something different.I have no inductor meter and i need to convert all inductors to 10x microHenry ( i plan to use resistor type inductors if possible) So do i have to recalculate all caps? I have 10 mH (micro not mili :) and 100 mH.So could you tell me how to calculate them? Or better could you recalculate them for me please?( If possible)

@Flatulent :

Thank you for your kind warning.There is no prohibition in my country and tv equipped cars can be imported legally.So i think it is legal.

@sda :

I have a fixed antenna about 30-40 cm long.I think i can do that with this antenna and if possible i don't want to install extra antenna.

Thanks again.

Analyzer.
 

Borber

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Inductors

You must not change the value of inductors and capacitors. They are calculated for 75Ohm impedance and frequency bands as needed.
Winding data for inductors are given in picture.
 

yellowtooth

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U have only one ANT ?
Or U want to use one ANT for both equipments ?
I think if the Freq is the same, then U need a switch.
 

S

sick_man

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Analyzer said:
Hi,

Thank you for your kind replies for my problem.I think i need to reply answers.

@Borber :

Your schematic is very interesting i will try it but i need to ask something different.I have no inductor meter and i need to convert all inductors to 10x microHenry ( i plan to use resistor type inductors if possible) So do i have to recalculate all caps? I have 10 mH (micro not mili :) and 100 mH.So could you tell me how to calculate them? Or better could you recalculate them for me please?( If possible)

@Flatulent :

Thank you for your kind warning.There is no prohibition in my country and tv equipped cars can be imported legally.So i think it is legal.

@sda :

I have a fixed antenna about 30-40 cm long.I think i can do that with this antenna and if possible i don't want to install extra antenna.

Thanks again.

Analyzer.

you calculate 10 mH by taking a 100R resistor and wind ten turns round with .512mm ecw
this will give 10mH as for 100mH do the same but use 5 turns on a 1k res

values are ~aroundabout right
but for uhf i would use ferrite beeds with 2 turns of .512 to give the chokes rather than resistors esp in a car situation {avoids noise}

a nice dual band preamp is all thats needed
or perhaps make a 5/8 over 5/8 or 7/8 over 7/8 over7/8 colinear for tv band 600MHz or so

this way it will be a 1/4 or 5/8 wave at vhf

and a simple diplexer tank design to give filtered signals on the needed bands

adding amplification also

this antenna is a vertical so can be mounted under the car and is about 50 cm long
placed in plastic tube {from heating system} {white plastic please}

and will give a realy nice signal

if you can mount it on the outer upper part
then do it
maybe on the side of the front windscreen or on the lip of the boot flap
 

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