How to find the location of an pirate radio studio

[darkm4n]

Hi ,

Do you know the way or the scheme of an fm tracker ?
I want to track an fm pirate that transmitt on 104.6 Mhz .

I need an directional antenna ? Or what ?

Can you help me with an schematic ?

THANKS !

[UrSv]

You need a receiver with a directional antenna, a good map and two points sufficiently far apart with a direction. AFAIK.

[darkm4n]

Hmm .. I know the zone the transmitter is located , i don't know the house . I know it has a 3 element yagi antenna , a 15 w transmitter ..

Do you have a scheme for such a antenna and a receiver ? i need a highly directional antenna .

[Magura]

Depending how much you have it narrowed down, a simple reciever and an antenna in a 4 inch lead pipe will do. Did that back at boarding school to find a low power FM transmitter.

Magura

[darkm4n]

Hmmm...

I god the receiver , i don't got the antenna .

What type of antenna ? What tipe of tube ? metal ? plastic ?
What i have to do once i got the antenna and the receiver ,how i detect the location ?

[phase_accurate]

If you are that close you could use a simple dipole or a so called HB9CV antenna (having better directionality than the former but more complicated to build).
When using a simple dipole, first check for the coarse direction by finding the maximum of the signal strength. Then check for the minimum to get a finer resolution (if you have a look at the "double eight" polar diagram of a dipole you will recognise that the minimums are much sharper than the maximums).
As already mentioned you have to do this this from two points to get the location.

Regards

Charles

[darkm4n]

Hmmm...
The problem is i need a small antenna ... not a dipole ...
Something small .. and directional ...

Why i need two points ? I can go in the direction of the signal ... till i find the antenna... ?

[Magura]

Originally posted by darkm4n
Hmmm...

I god the receiver , i don't got the antenna .

What type of antenna ? What tipe of tube ? metal ? plastic ?
What i have to do once i got the antenna and the receiver ,how i detect the location ?

A lead pipe(Pb) rolled of 2mm sheet.

The antenna was just a piece of wire back then, held in the center of the pipe by some soret of tape or something(must be plastic). The antenna must be 3 to 4 inches shorter than the pipe in order to not pick up signal from other directions than straight in fron of the pipe. The rear end of the pipe must be closed, and the reciever must be shielded(Al folium or something like that).

Magura

[darkm4n]

Magura

Can you make a drawing ? i can't really understand ...
Or ..

What diameter the pipe has to be ? Metal pipe ?
Where to put the wire inside the tube ? Cooper wire ?

[Magura]

Could be copper wire. Yes as i wrote it should be lead (Pb) pipe.

The wire must get in the pipe througn a hole drilled in the center of the bottom of the pipe. and must be held in the center of the pipe (stretched) to approx. 3 inches from the front end.

Magura