Airborne Speed Trap Countermeasures - Revisited

I do like the Zoan MRX a lot. I also like the ProxAlert R5, and spotted a used one on sale for 375 dollars.

One thing that I have noticed, is that all of the current offerings are smart enough to take your altitude into account, and only give verbal warnings when something crosses that threshold. That's great for it's intended purpose, but not as good for us. The good thing is that they usually still track traffic even if you don't get the audio warning. I would consider putting the device on my dash, so I can include it in my regular visual scans of the road.

I think a dumber unit that falses all the time (audio) would be ideal for our purposes.

A little fuel for the discussion about a DIY unit that might suit the needs of a fast driver better.

It seems that there is a change afoot in the Aviation industry with regard to how transponders are used. The future of the transponder lies in a system called ADS-B. Mind you, I know very little about this yet. I figure there are probably others in here that would be better ablle to take this and run with it than I am.

ADS-B will replace the entire transponder/radar infrastructure that has been in use since the 1940s. It essentialy uses the 1090/1030 MHz frequencies to transmit a much more complte set of data. This will greatly enhence the safety of Air Traffic Control. One of the things that I think is most impoortant is that the new system uses the same 1030 MHz frequency that all transponders currently use. This means if we are detecting nearby aircraft using this signal, we should be able to continue to do so (thoeretically).

There are a number of hobbyists who are building thier own ADS-B stations and using them to track aircraft. There is hardware available that a hobbyist can hook up to a computer, that interfaces with software to do the same thing as the current ATC mechanisms. They are even sometimes used to show an airplane tracking map over the Internet.

You can probably imagine that this would possibly allow you to know the position and altitude of every airplane withing 40 or more miles of your location, and use software to weed out the ones that aren't likely to be speed traps.

Another more immediate possibility is that someone could take the reciever module and weaken it's sensitivity to only a few miles, then connect it to an LED scale like a radar detector. Presto! Airplane detector!

Here is one such hobbyist that I was able to find, and fodder for much googling for those who are interested.

http://miniadsb.web99.de/

Forgot to mention who we saw right after we landed....

http://www.reddevilstudios.net/quick...gm8g4s9012.JPG

rumored that the FHP flies out of the same airfield we use

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Originally Posted by switch626

I do like the Zoan MRX a lot. I also like the ProxAlert R5, and spotted a used one on sale for 375 dollars.

One thing that I have noticed, is that all of the current offerings are smart enough to take your altitude into account, and only give verbal warnings when something crosses that threshold. That's great for it's intended purpose, but not as good for us. The good thing is that they usually still track traffic even if you don't get the audio warning. I would consider putting the device on my dash, so I can include it in my regular visual scans of the road.

I think a dumber unit that falses all the time (audio) would be ideal for our purposes.

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I disagree, it depends on what the threshhold is. Audio warning for tracking a ton of planes could be mad annoying in an airport city.

[QUOTE=Lucky225;760809]

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Originally Posted by switch626;760683

I think a dumber unit that falses all the time (audio) would be ideal for our purposes.[/QUOTE

I disagree, it depends on what the threshhold is. Audio warning for tracking a ton of planes could be mad annoying in an airport city.

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Hmmm, I think that came out wrong.

I meant that with reagard to it's function as a collision avoidence tool. They limit false alerts by narrowing the altitude that the unit will respond to. Opening that up to say, 3000 feet, would provide more falses to a pilot using the device. However, it would ensure that you are alerted audibly to aircraft that are around 2500 feet that would be good candidates for a speed trap. Restricting that response to 500 or 1000 feet would leave your device silent to planes that could very well be running traps.

In te latter scenario, all you would have would be tracking informatiin displayed on the screen. This could still help you spot a trap, but will not grap your attention.

[QUOTE=switch626;760835]

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Originally Posted by Lucky225

Quote:

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Originally Posted by switch626;760683

I think a dumber unit that falses all the time (audio) would be ideal for our purposes.[/QUOTE

I disagree, it depends on what the threshhold is. Audio warning for tracking a ton of planes could be mad annoying in an airport city.

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Hmmm, I think that came out wrong.

I meant that with reagard to it's function as a collision avoidence tool. They limit false alerts by narrowing the altitude that the unit will respond to. Opening that up to say, 3000 feet, would provide more falses to a pilot using the device. However, it would ensure that you are alerted audibly to aircraft that are around 2500 feet that would be good candidates for a speed trap. Restricting that response to 500 or 1000 feet would leave your device silent to planes that could very well be running traps.

In te latter scenario, all you would have would be tracking informatiin displayed on the screen. This could still help you spot a trap, but will not grap your attention.

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No totally agreement, if you can't SET the threshhold and it's pre-set to 1000 feet, that can definitely be an issue as a countermeasure.

Switch, on your real encounter with the airborne speedtrap can you answer these questions:
1. Did you ever see the aircraft
2. If so, was it a high wing or low wing airplane?
3. Compared to the simulated encounter was the airplane lower or higher? Closer or further away from the centerline of the highway?
4. What was the closest distance indication shown on your TPAS?
5. On your trek down to Kendall Lakes, did you ever receive any "false" warnings? Were there any other aircraft that tripped the audio alerts?

What is the difference between the MRX and MRX-A?

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Originally Posted by thx1138

Switch, on your real encounter with the airborne speedtrap can you answer these questions:
1. Did you ever see the aircraft
2. If so, was it a high wing or low wing airplane?
3. Compared to the simulated encounter was the airplane lower or higher? Closer or further away from the centerline of the highway?
4. What was the closest distance indication shown on your TPAS?
5. On your trek down to Kendall Lakes, did you ever receive any "false" warnings? Were there any other aircraft that tripped the audio alerts?

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1. I never got a visual on the aircraft.
2. I never saw it.
3. Closer, stronger alerts, lots around 0.5 nm. I can't tell if it were closer by visual, but by alerts it definately seemed like closer than our tests. In out tests I had few critical alerts, mostly the lesser warning (heads up instead of prepare to die)
4. Closest reading was 0.3 nm, which is the closest reading i ever get. t will alternate between 0.3 and 0.4 when I'm near the runway near FLL and it looks like the plane is aslmost going to land on top of me. It NEVER gets a 0.0. According to the manual, it is only accurate within 1800 feet.
5. On the way down I had a few false alerts. Mostly near FLL and MIA. There was even one about 3 miles before I started picking up on the FHP plane. I could tell when I was tracking the real thing because the TPAS's numbers started to jive with the distance to the lines on the GPS (I had marked these and other site before hand). Once I got near the lines, the alerts were fast and furious.

Perhaps a cheaper alternative to a PCAS or similar device could be a scanner like project. You don't want an actual scanner unless you have a HAM license.

Build a kit like http://www.tentec.com/index.php?id=52 and tune it to 1090 MHz. Maybe put the knobs inside the case so they can't be bumped once they are set correctly.

You might then put the output through some kind of LED strength meter. Maybe the volume knob would function as a way to adjust sensitivity.

Once you get the details worked out, you could sell them on here for a profit, and we would be safe from airplane tickets ;)

Just a thought. Maybe we have an electronics whiz on here that can take the idea to the next level.

I have the PCAS MRX and I haven't used it yet. I need to get it updated and put it up on the dash to test out. When your busy, your busy.

That's good news. I'm looking forward to hearing about your experience with th PCAS.