Scantenna

[longdistancelistener]

If im using a Scantenna to listen to public safety(mostly 150MHz) but want to monitor multiple systems that are in different parts of the city, does it matter what direction I point the Scantenna? In other words, some of the towers are south of where Im at, some are way up north, where should I be aiming?

Thanks

 

[Bucko]

The ST2 is omni but does show some directional depending what you have it mounted on. I have mine on a tower and does appear to be a bit directional depending what signal is between it and the tower and which way the elements are angled. My CM5094A acts similar also which is mounted opposite and above the ST2 ( is a vert dipole like the ST2). My guess it would be less effected if mounted on a standard mast pipe.

 

[longdistancelistener]

The ST2 is omni but does show some directional depending what you have it mounted on. I have mine on a tower and does appear to be a bit directional depending what signal is between it and the tower and which way the elements are angled. My CM5094A acts similar also which is mounted opposite and above the ST2 ( is a vert dipole like the ST2). My guess it would be less effected if mounted on a standard mast pipe.

Bucko, thanks for the info. I guess I will just set it up and make slight adjustments if needed. Thanks again

 

[kb2vxa]

Due to the type of mounting the Scantenna does show a slight directionality. To avoid "shading" I suggest mounting it on a short length of PVC extending slightly below the bottom element, from there down steel mast gives better support than completely PVC mast. ANY antenna side mounted on a tower exhibits directionality due to the fact the entire length of the antenna is shaded by the tower and it's a whole lot bigger obstruction than a small diameter mast.

 

[WayneH]

Moved to the Antenna forum. Please take a moment to look over all forums before creating a thread. Thanks.

 

[rbm]

I currently have three Scantennas mounted around a metal mast.

There's enough difference in the directivity of them that I can receive distant signals full quieting on one of them and barely copy them on one of the others.

For example, in the milsat range of 245-270 mHz I can receive 255.550 MHz on one of them at S-9 and the other two barely move the s-meter. (Since that frequency is active now, I just tried two of the antennas. One is S-8, full quieting, and the other is S-1 about 25% noise.)

On several of the NOAA weather frequencies I receive different broadcasts depending on which of the antennas I use.

They favor reception in the direction of the mounting boom away from the mast.

Rich

 

[smokeyjones666]

I currently have three Scantennas mounted around a metal mast.

You know, I'd love to see a photo of that.

 

[rbm]

You know, I'd love to see a photo of that.

I didn't think I had a photo around. It took a while to find this one.

Usually, I just take a photo before I go on the roof to do antenna work and then I delete the photo when I'm done.

This was taken a few years ago after a wind storm. Before I took a new antenna up to replace a broken one.

The antenna on the left is broken (Kind of obvious). It was the only one of the three that had the blue plastic insulator and the second one of that type that broke the same way. The other two had been up there for 15 and 13 years with no problems.

The three round things down the mast a little are weather resistant housings for pre-amps as shown in the photo in this post.
http://www.radioreference.com/forums/showpost.php?p=860180&postcount=5

Rich

 

[Bucko]

The antenna on the right looks like a Channel Master 5094?

 

[rbm]

The antenna on the right looks like a Channel Master 5094?

Yep. That one has been bullet proof.

I normally keep two new spare Scantennas in boxes in the garage. I've had several problems with them over the years. Bent, broken elements, broken insulators, bad/intermittant electrical connections to the elements, etc.

Rich

 

[Bucko]

Yes the ole CM appears to a sturdy built antenna, too bad they don't make them anymore. Over the years I have only lost one CM from high winds but it was really caused by another item on the tower.