Thread: Build a cheap FM antenna for bench testing

Just wanted to let everyone know I found a way to get crystal clear FM reception while the carPC is on the test bench. I have a Visteon HD radio and it would never get any stations until I built the correct Antenna. I did some research and figured out the Motorola style connectors are 75 Ohm.

So you need 2 items,

1) 300 ohm Dipole FM Antenna
2) 75 ohm to 300 ohm matching transformer.

You can build a Dipole very easy, instructions can be found here:

http://kgnu.org/ht/helpfm.html#makeantenna

Or in my case I ended up finding one premade at a local electronics store for $3.99 with nice mounting ends on it. (Radio Shack has the goods too.)

I found the matching transformer at the same store $1.99

Since the transformer is made for TV I took it apart and soldiered my antenna connections. There are 2 screws on the outside of the transformer, the FM dipole screws onto them. Take the coax style Motorola and cut and end off. Strip back the ground and solider it to the outside terminal on the transformer. Strip the center section and solider that to the inner pin on the transformer. Viola! Pin the dipole straight across to a wall or board and mount it horizontal, even better if it's over a window. Plug in the Motorola connector to the HD tuner and bingo crystal clear FM with HD sub stations. I live quite far from the broadcast towers which is why I ended up doing this.

I am sure this would work with other FM tuners out there to, just find out if they are 75 ohm or 300 ohm antennas. If you have 300 ohm then you don't even need the matching transformer.

::Jammin out to FM with some headphones on::