Antenna Horn

[Motor On]

Has anyone followed the lines of Spectre's making a larger external horn and made a larger horn for greater sensitivity for their RD? Not the spectrum analyzer posted last month, but something small and capable of being clipped onto the front of an RD. I've got a few inches in front of my V1 and the extra sensitivity could be useful vs I/O if something could be designed to look further down the road. I'm still doing research on antenna theory in that range and was curious if anyone had ventured in that direction. And if it's something that innocently sits in front of the device then it's not messing with any FCC regs either.

[STiMULi]

Funny, I was thinking about the same thing the other day. On the RX65 part (1/4th) of the horn is an unetched segment of the PC board. I would think that the thickness would play a part on it, but that is a thin piece of copper.

Having a very small education on microwave except cooking and avoiding LEO I would like someone to enlighten me.

Would it help enough to add a metal horn in front? Would we have to disassemble the product and join the horns.

[North Alabama]

The angle of the hood for reflections should help like a large horn. There was one RD model but cannot say the name but was used by truckers years ago that had a large horn and it helped.

[STiMULi]

The angle of the hood for reflections should help like a large horn. There was one RD model but cannot say the name but was used by truckers years ago that had a large horn and it helped.

Did it have a number in the name?

[jimbonzzz]

Something like this? (photo courtesy if flitsservice)



It's been done before (and discussed on here before). In this case, it was done to provide useful warning to weak overseas photo radar. But you don't get something for nothing. Off axis detection suffers, because when you increase the aperture size of the antenna for more gain, it also becomes more directional. This is a difficult concept for some people to grasp, since they might see the antenna as being "wider" and think it is actually more likely to catch off-axis signals. But depending on what you are looking for, the tradeoff can be a good solution (like in this case).

[Motor On]

Almost exactly what I was thinking, but a little smaller and a little more easily detachable, not going for laser eye surgery here or even a telescope, more low power binoculars. I'm in the Midwest, so we've got the benefit of when you get out of the city things are fairly straight and flat. I was thinking put together measurements for a simliar antenna to that, paint the outside of it black, and be able to velcro it to the fornt of the V1, or make some sort of bracket that I could snap it into place. A little bit of extra reception down range may be just enough to break the threshold if he's hidden behind a bridge or sitting on an on-ramp, making me rely on reflected signals in sparse traffic. Then when the terrain changes, or I pull off into a city or suburbia, reach up, disconnect the horn and tuck it in the glovebox.

Have some links or key words to search for? I'm thinking it'll only be a few db of gain but any little bit helps vs I/O and I want to make sure I plan it out and get the dimensions as optimized as possible for 24.150Ghz and 33-36GHz. K band testing would be easy, Ka would be a little harder for scientific results though.

Something like this? (photo courtesy if flitsservice)



It's been done before (and discussed on here before). In this case, it was done to provide useful warning to weak overseas photo radar. But you don't get something for nothing. Off axis detection suffers, because when you increase the aperture size of the antenna for more gain, it also becomes more directional. This is a difficult concept for some people to grasp, since they might see the antenna as being "wider" and think it is actually more likely to catch off-axis signals. But depending on what you are looking for, the tradeoff can be a good solution (like in this case).

[North Alabama]

The older analog units were larger to get better -db gain from the larger horn. The technology did not improve untill the GAS diodes were used in the horn, but then there were trade offs there to. I always wondered if wire or copper foil cut to the right length could be placed in front of the auto and connected to the RD would help some way? I to do not have that knowledge.

[nine_c1]

Something like this? (photo courtesy if flitsservice)



It's been done before (and discussed on here before). In this case, it was done to provide useful warning to weak overseas photo radar. But you don't get something for nothing. Off axis detection suffers, because when you increase the aperture size of the antenna for more gain, it also becomes more directional. This is a difficult concept for some people to grasp, since they might see the antenna as being "wider" and think it is actually more likely to catch off-axis signals. But depending on what you are looking for, the tradeoff can be a good solution (like in this case).

Good googly moogly! With all the pains the top end manufacturers go through to optimize impedance matching and phase error correction (due to the short horns) how does slapping a simple horn extension on the RD, like this, not make it worse?

[STiMULi]

Something like this? (photo courtesy if flitsservice)



It's been done before (and discussed on here before). In this case, it was done to provide useful warning to weak overseas photo radar. But you don't get something for nothing. Off axis detection suffers, because when you increase the aperture size of the antenna for more gain, it also becomes more directional. This is a difficult concept for some people to grasp, since they might see the antenna as being "wider" and think it is actually more likely to catch off-axis signals. But depending on what you are looking for, the tradeoff can be a good solution (like in this case).

Thanks!

It looks like a worth trade off. I have been thinking of shoving a weatherproofed 9500ix under the hood in a vertical manner just for the mobile cameras. (I am not moving forward with it at the moment as it seems they may go away in AZ in the next few months)

It may be worth it to empower the same 9500ix in the same location but horizontally mounted for an extreme (or more distant at least) look ahead for otherwise faint I/O hits.

I just spent a good while looking the discussions. If anyone can point us in the right direction i think it would be good reading!

[zerbey]

As others have observed, that's just going to make for a more powerful very directional antenna. In addition, you're going to have every cop that sees it pull you over to find out WTF it is.