"J" function on crack today?

[sethy]

I was rolling up to a red light, when I get a brief KA alert followed by a J, then imediatly, another KA followed by a J, then it just started making the J sound constantly back and forth while flashing J for about a minute.

I am guessing that the J function is only supposed to weed out 1 fallse at a time? I guess there was 2 detectors, and when one was hit with the J it would J the other one, then go back to the first one and J that one....Does that makes sense?

Mike if you are still around, care to provide some input on this one?

[thestaton]

haha that is pretty crazy. I had a fairly scary experience yesterday a known Ka photo radar source I was going to video tape to show the distance on the V-1 which it picked up 2.2 miles out in little L. However at the first alert I didnt wanna hear the noise for 2.2 miles so I muted it out. 5 seconds later it calls it J and I get no more warning.

I'm freaking out because this thing just J'd a known Ka source. I did the test 6 more times to see if it would do it again, and it didnt. I cant explain why it would do this but man that was weird.

[RacerX]

i had a similar experience once.
i was coming towards and over an on ramp, picking up a ka alert from DPS. they were clocking people coming around the corner behind them. as i went over the top and above/passed him, the arrow went to the rear, then a few moments later suddenly it flashed the "J" and stopped.
i'm hoping it was a fluke in that it picked up another detector just as i got out of distance from the known source.

[brick]

I think that you guys should DEFINITELY contact VR directly about this. If their firmware is flawed (or worse, buggy) they should know about it.

[sethy]

I think that you guys should DEFINITELY contact VR directly about this. If their firmware is flawed (or worse, buggy) they should know about it.

I DONT KNOW WHAT WE'RE YELLING ABOUTTTT!!!!

[brick]

LOUD NOISES!!!!

[sethy]

lmao

[fallen8511]

If I do get a V1, I think I'm just going to disable the J feature anyway, less falses and no pop protection sounds fine to me...

[sethy]

wouldnt you get more flases with the J feature disabled?

[happya$$]

well the "dee da doo" would not sound off. That is the only difference.,

[brick]

About the falsing on Ka, this would be an interesting thing to test. I have two theories:

1) The original 1.8 sometimes does false on other detectors even with the false alarm guard on. (Though it's rare.) If the false alarm guard has not changed, these falses will remain un-terminated in the new version. Shorter signals, filtered out entirely in the original 1.8, show up on POP detectors but are terminated by the J indicator. This means more falses, but the new ones are resolved. The driver sees the world about the same as with the old 1.8.

2) The false alarm guard has actually been improved due to the advent of the J alert, meaning that the falses that got through before will get through at first but eventually be terminated with a J. Same goes for the additional alerts picked up by POP mode operation. This means more falses again, but both they are all resolved. This would be an improvement the way I see it.

Insight? I wish Mike V. would answer this kind of question.

[sethy]

The only prob with having reps on the board is the fustration whent hey dont post, but if you think about it they have a leginimate reason not to post. They can not post a lot of the information we want to know or else they will tip off the competition. A simple question we ask may have costed them millions...

[jimbonzzz]

Brick nailed it. I believe his theory #1 is 100% correct.

Here's how I believe it all works:

False Alert Guard
The Valentine determines if a Ka alert is false from a leaky detector by also looking for the 2nd harmonic frequencies that are the "footprint" of a false alert. This is because real police radar does not emit these frequencies, however leaking detectors do. The Valentine keeps track of these detected harmonic frequencies during it's regular sweep. If no "harmonic blocking" signal is detected within the 10 seconds before, or within 3 sweeps after the Ka radar is detected, then it reports the Ka alert. However, if it DOES detect a "harmonic blocking" signal within this time frame, then it assumes that the detected Ka is false and no alert is repoted.

You might think that this would be dangerous if you were next to a junk detector and police were running Ka band, however that is not the case. In order for the alert to be suppressed, the Ka signal and the blocking signal must also have a harmonic relationship. Also, only a certain range of the Ka band is likely to contain false Ka harmonics generated by other detectors. So this method is really pretty safe.

This does suppress the false alerts most of the time. Although the 2nd harmonic (~22 GHz) is usually stronger than the 3rd harmonic (the Ka false) it is not always able to be detected right away because of factors such as K-band bandpass filtering in the other detector. Therefore, some false alerts DO make it through anyway.

The Valentine is not the only detector manufacturer to use this technology of detecting "harmonic blocking" signals to suppress the Ka falses from other detectors. Many detectors use their own versions of this scheme, including the Escort (and probably BEL too).



"J" Feature


"J" stands for "J"unk signal.

OK, why did we add this new feature? Because it was the best way to give beyond-line-of-sight warning capability for POP-radar signals while not burdening the user with an excess of unresolved alerts (false alarms).

The "J" feature uses the same technology (detecting "harmonic blocking" signals) as the false alert guard.
Before POP was added, some very short, quick Ka signals that make it through the false alert guard were also were also dismissed as a false by the Valentine since these were also mostly from the leaky detectors. But with the introduction of POP, the Valentine must report these signals immediately just to be safe, since they could be POP radar. With the "J" feature, once a Ka alert is already in progress, if the the Valentine detects a "harmonic blocking" signal, then it terminates the alert with a "J".

With POP enabled (menu selection "J") you would get MORE falses than with it off.

The technology to suppress the falses from other detectors has been in place in the Valentine for a long time. The "J" feature is for better POP protection while resolving false alerts that come with this better protection, NOT for better protection from false alerts in general.



"Professor" Jim

[sethy]

Jim, would I get better KA range if I had POP disabled?

[jimbonzzz]

Jim, would I get better KA range if I had POP disabled?

I don't really have an answer for that one. My gut feeling tells me that there shouldn't be much of a difference either way. I run with POP turned on...

You might get increased range with the "False Alert Guard" turned off, I saw people post that they had tested this with photo radar. However, you probably wouldn't be able to stand all of the falses.

[RacerX]

I think that you guys should DEFINITELY contact VR directly about this. If their firmware is flawed (or worse, buggy) they should know about it.


You called that on the money.
http://www.radardetector.net/%26quot%3BJ%26quot%3B-%3D-get-the-new-revision-on-V-1.-1444t.php

[shooter2jim]

Jim, would I get better KA range if I had POP disabled?

I don't really have an answer for that one. My gut feeling tells me that there shouldn't be much of a difference either way. I run with POP turned on...

You might get increased range with the "False Alert Guard" turned off, I saw people post that they had tested this with photo radar. However, you probably wouldn't be able to stand all of the falses.


I found that in my old 1.8 with the suppression off, the reaction time to my Ka gun was incredible, to say the least. Practically analog-like reaction times. Too bad you really would't want to drive around all day and put up with all the falses. I would put money on my old 1.8 with "6" disabled against POP radar. How 'bout a little viedo, Chris? With my new V1, I don't see much if any difference with "6" disabled. It's reaction time is pretty awesome as it is. Maybe I could try it with 6 and J disabled.

JiM