Yagi antenna for scanner

[nyctransit5959]

I just bought a used BC9000XLT and want to listen to vht fm broadcast radio stations. I can hardly pick up radio stations with the antenna that came with it. Does anyboby know of a short 3 element outdoor yagi antenna that will work with this scanner or am I expecting too much because it's a wideband scanner and not a 88 to 108 mhz band stereo receiver?

 

[JDKelley]

You may end up having to make something yourself for that band (although I could be wrong - it's happened before!) A Yagi is a directional antenna, so do you know where the radio transmitters are? Not the studios, the actual transmitter aerials themselves. Those are what you're going to need to point at.

There are plenty of works on designing antennae for the apt pupil, so the material is out there, and I don't recall the maths being overly onerous.

You may also want to look for RDF (Radio Direction Finding) antennae for DF contests, finding one for the 2 m band will be close to what you want to work with (broadcast FM runs 88-105 MHz or so, 2M runs about 145-150MHz, give or take. I'm not looking at a band plan right now.)

If you do not know where the station's transmitter aerial is, you may be better off using a discone with a vertical element protruding from the top (tune the vertical for the desired frequency band,) or a vertical 1/4- or 1/2-wave dipole to pick up what you want - tune the length for the middle of the band you want. If there is a primary station you want to listen to, then tune for that station (but, since stations have been known to move, better to tune for the middle of the band. Figure FMB for 88-104 MHz, so 104-88 = 16, 16/2=8, 88 + 8 = 96, tune for 96 MHz. Feed the dipole from the centre, the discone is fed from the bottom by CoAx - the jacket connects to the cone, the centre conductor connects to the disc and vertical element. For the discone, I'd tune the vertical for 1/4-wave at 96 MHz.

Antenna maths can be found here and at various locations online, there are also a number of references available for purchase, starting with the ARRL Antenna Book, available at Amazon for $70, shipped. I would not wish to deprive you of the chance to hone your Google-Fu. . .

 

[AK9R]

Back in the days when home stereo was popular, you could buy directional antennas specifically made for receiving FM broadcast. Those antennas may not be easy to find these days.

A Yagi antenna is tuned for one frequency. The FM broadcast band covers 88 to 108 MHz, so the antenna would need to be broad-banded. This is where log periodic antenna designs come into play. The classic home TV antennas are log periodics. For that matter, a TV antenna designed to cover VHF Low (channels 2-6, 54-88 MHz) and VHF High (channels 7-13, 174-216 MHz) would, most likely, include the FM broadcast band.

The classic dipole antenna made from twin-lead that was widely used for home stereo is somewhat directional. It will hear better off of the sides than off of the ends.

You can look up FM stations in the FCC's FM station database. That will tell you the transmitter location.

 

[bearcatrp]

A discone would probably do the trick. Can you put up a antenna outside your home? If so, it needs to be higher than your roof top.

 

[dlwtrunked]

I just bought a used BC9000XLT and want to listen to vht fm broadcast radio stations. I can hardly pick up radio stations with the antenna that came with it. Does anyboby know of a short 3 element outdoor yagi antenna that will work with this scanner or am I expecting too much because it's a wideband scanner and not a 88 to 108 mhz band stereo receiver?

Because of the wavelength of VHF FM broadcasts stations, "your definition of "short" may not be possible. Also, no where have I seen polarization of the signal mentioned. If you want maximum reception, that needs to be considered. Most FM broadcast stations are circularly polarized. (A few are horizontal only polarized.) A Yagi will only be vertical or horizontal polarized. Those and a discone will work but are not going to not be ideal.

 

[mmckenna]

Amazon.com

If you really need 3 elements, you could chop off the front director and part of the boom. They are not 'short' though.
Some of the old TV antennas worked well on FM broadcast, since the lower VHF channels were stacked up just below the FM Broadcast band. If you can find one of those, it would work, but again, it won't be short.

But, I'd agree with AK9R, try making your own dipole first. It's easy to do, and will work way better than the stock antenna. Might be all you need.