Horizontal v Vertical

[barryswanson]

After a few close calls my STi-R is going back to vertical. This difference it makes is freaken insane! I'm talking like 100m compared to 2000m. Ka doesn't seem any different.

Looks like the advice on that slip of paper shipped with your RD was good!

It sure was! I could not get over the effect cross polarization has. Truely amazing. The only thing that worries me is the fact that there are a few Stalkers getting around. Not as many as Decutars but there are some.

At least the standard moving radars like the Stalker and Decatur use circular polarization which are compatible regardless of how you mount your horn. Your off axis detection may suffer a bit but over the hill detection might even improve?

I thought Stalkers where vertically polarized? Or is that just the hand held units?

[nine_c1]

After a few close calls my STi-R is going back to vertical. This difference it makes is freaken insane! I'm talking like 100m compared to 2000m. Ka doesn't seem any different.

Looks like the advice on that slip of paper shipped with your RD was good!

It sure was! I could not get over the effect cross polarization has. Truely amazing. The only thing that worries me is the fact that there are a few Stalkers getting around. Not as many as Decutars but there are some.

At least the standard moving radars like the Stalker and Decatur use circular polarization which are compatible regardless of how you mount your horn. Your off axis detection may suffer a bit but over the hill detection might even improve?

I thought Stalkers where vertically polarized? Or is that just the hand held units?

Only the Stalker ATR (handheld) used Vertically Polarized horns.............one for transmitting and one for receiving.











The newer handhelds and standard two piece units all use a single conical horn which is circularly polarized.

[HueManatee]

How do you mount it vertically? Do you have to buy different mounts? The one that came with my RX65 makes it sideways...

[nine_c1]

How do you mount it vertically? Do you have to buy different mounts? The one that came with my RX65 makes it sideways...

The horn inside your radar detector is vertically polarized when the Radar Detector is mounted flat like this.




Some folks in Europe and Australia mount their detectors vertically (on edge) to change orientation of the detector to pick up Horizontally polarized photo radars like the Gatso and Multinova.

[ame=http://www.youtube.com/watch?v=VIPa6rduehU&feature=player_embedded]YouTube - Vertical Mount Radar Detector Bracket[/ame]#!


So mount your detector horizontally and it's vertically polarized, mount it vertically and it's horizontally polarized.

Clear as mudd right.

[nano]

The horn inside your radar detector is vertically polarized when the Radar Detector is mounted flat like this.

But obviously not every detector uses vertical polarization.

I've done some tests with the Whistler Pro-78se Rev.C against Multanova 6F: The detection vertically was considerably less than mounted horizontal.

Delonix experienced the same phenomenon: http://www.delonixradar.com.au/radar...-Multanova.jpg

Some folks in Europe and Australia mount their detectors vertically (on edge) to change orientation of the detector to pick up Horizontally polarized photo radars like the Gatso and Multinova.

Just a friendly comment: The photo radar is called Multanova.

The company Multanova was founded 1952 in Switzerland and has today 15 employees. Their focus is concentrated on traffic surveillance devices (e.g. Multanova 4F, Multanova 5F, Multanova 6F, Multardar C)

I don't want to be nitpicking, just to avoid any confusion that there could be two different photo radar (Multinova/Multanova).

[nine_c1]

The horn inside your radar detector is vertically polarized when the Radar Detector is mounted flat like this.

But obviously not every detector uses vertical polarization.

I've done some tests with the Whistler Pro-78se Rev.C against Multanova 6F: The detection vertically was considerably less than mounted horizontal.

Delonix experienced the same phenomenon: http://www.delonixradar.com.au/radar...-Multanova.jpg

Some folks in Europe and Australia mount their detectors vertically (on edge) to change orientation of the detector to pick up Horizontally polarized photo radars like the Gatso and Multinova.

Just a friendly comment: The photo radar is called Multanova.

The company Multanova was founded 1952 in Switzerland and has today 15 employees. Their focus is concentrated on traffic surveillance devices (e.g. Multanova 4F, Multanova 5F, Multanova 6F, Multardar C)

I don't want to be nitpicking, just to avoid any confusion that there could be two different photo radar (Multinova/Multanova).

Thanks for the comments/corrections............always appreciated.

The comment about the Whistler is very interesting. I can't imagine Whistler using a horizontally polarized horn. Perhaps it's circularly polarized?

Maybe this also explains why the Whistler is more difficult to detect with RDDs. I'd bet the horn in the Spectre RDDs are vertically polarized like most detectors.

Edit: Hmmm.........scratch the polarization theory. Looks like a typical vertically polarized ridged horn to me in the FCC photos. The ridge makes the microstrip connection on the top meaning the ground plane is on the bottom.......thats vertically polarized me thinks.

[nano]

The comment about the Whistler is very interesting. I can't imagine Whistler using a horizontally polarized horn. Perhaps it's circularly polarized?

I just looked at MEM-TEKs review of the Whistler Pro-78se. He also stated that the horn antenna is vertically polarized.

That makes it even more interesting that detection on horizontal polarized radar is in vertical position worse than horizontal.

I searched for my test results with the Whistler Pro-78se against Multanova 6F (f=34,3 GHz):
Horizontal position: 170m (0.10563 miles)
Vertical position: 140m (0.08699 miles)

Just for comparison, the STI-R detected the photo radar in 0.27962 miles (450m)

Maybe this also explains why the Whistler is more difficult to detect with RDDs.

I think the short detection is due to the RF absorber which is attached behind the horn antenna.

Unfortunately there isn't an inside picture of the antenna in the FCC report. I would open mine, but I'm afraid it isn't the best idea to open the antenna, or??

Edit: Hmmm.........scratch the polarization theory. Looks like a typical vertically polarized ridged horn to me in the FCC photos. The ridge makes the microstrip connection on the top meaning the ground plane is on the bottom.......thats vertically polarized me thinks.

Interesting. How can you identify that the horn is vertically polarized? Just because of the ridge?
Btw. does "ridge" stand for the "heightening" in the middle of the horn (e.g. on page 13 of the fcc report)? English isn't my first language...

[nine_c1]

I think the short detection is due to the RF absorber which is attached behind the horn antenna.

Unfortunately there isn't an inside picture of the antenna in the FCC report. I would open mine, but I'm afraid it isn't the best idea to open the antenna, or??

How can you identify that the horn is vertically polarized? Just because of the ridge?
Btw. does "ridge" stand for the "heightening" in the middle of the horn (e.g. on page 13 of the fcc report)? English isn't my first language...

Yep.........that vein that runs down the top center of the horn is the ridge which comes down to make the electrical connection to the microstrip. Since polarity is specified by the electric field.......a top/bottom connection would be vertically polarized and a side to side connection would be horizontal.

Circular is coupled in a different way altogether.

I think Whistler just did their homework and optimized the horn to perform best against either polarity in it's natural mounting position? Doesn't seem logical that it would perform better against a horizontally polarized radar in the standard mounting position...........but I'm no expert on horn design.

AHA............I didn't know about the "RF absorber" ........that makes perfect sense.

[nano]

Thank you for the explanation!