J option.....

[venexoz]

So today going to work it came to my mind what is the point of the J feature? I'm not bashing. I mean it is a good feature but by what I understand it alerts you that it is receiving a Ka false?? Or it does something else?

I just want to know

[Ace_Racer]

It is just the V1's way of informing you that the KA signal is junk or false. Sometimes it is right and sometimes it is wrong. Both J's I've had have been correct ( cobra's)

Ace

[venexoz]

It is just the V1's way of informing you that the KA signal is junk or false. Sometimes it is right and sometimes it is wrong. Both J's I've had have been correct ( cobra's)

Ace

So it alerts you that there is a Ka signal, then filters it as a false and shows it to you as a J the whole time that it is there, right?

[Ace_Racer]

No only for about 2-3 seconds then disappears. The signal will and can come back if the V1 determines it is a real threat.

Ace

[venexoz]

Ohh cool, Thanks. I thought that it would stay there. That is cool that way you know it was a false and not just that the RD lost the signal.

Cool

[ES13Raven]

I understand it alerts you that it is receiving a Ka false?? Or it does something else?

This is part of the reason that people feel the Belscorts have better filtering.

The V1 takes the approach of "alert you first, then if the signal is verified to be junk - show a J"

The Belscorts might alert a second later, but that signal has already gone through all the filters. Hence Ka falses are very rare on the X50 and RX65 with POP off.

[Switchback]

with the fast alert time on the V-1 it might alert to a KA source before it determines if it is a valid signal or not. as compared to slower initial response of other detectors. during that slower initial response it might just get you ticketed.

personally, I like the "J" feature. I would rather get on the brakes first, then let the detector figure it out in the next couple of seconds if it is valid or not. if it is a leaky detector alerting, it will give you the "ooops, I screwed up" tones and flash a "J"

it sure is better than getting a false KA, and waiting to see where the non-existent radar source is.

better off to be safe than sorry. IMHO

[TheTexan]

I understand it alerts you that it is receiving a Ka false?? Or it does something else?

This is part of the reason that people feel the Belscorts have better filtering.

The V1 takes the approach of "alert you first, then if the signal is verified to be junk - show a J"

The Belscorts might alert a second later, but that signal has already gone through all the filters. Hence Ka falses are very rare on the X50 and RX65 with POP off.

I was under the impression that some signals it Junks without alerting you, the only time you get the J alert is if it determines the signal was junk after it had triggered an alert. Someone explained this perfectly in another V1 thread today.

Also I think the x50 and RX65 immediacy of response on Ka are both faster than the V1

[jimbonzzz]

Ka false alerts are usually caused by a "junk" detector with a 1st LO in the ~11.xx GHz range producing a harmonic in the police Ka band.

Both the Belscorts and the V1 use similar schemes to determine if the Ka alert is a false: if they receive a Ka alert, they look to see if there is a harmonically-related signal at ~11 GHz and/or ~22 Ghz. With real police radar, these signals would not be present. If they ARE present, the detectors suppress the alert altogether. In some cases, the 11/22 GHz signals are even detected before the Ka alert is, since the Ka alert is the 3rd harmonic it can be weaker than the fundamental @ ~11 GHz or the 2nd harmonic @ ~22 Ghz.

However, sometimes bandpass filtering is implemented in the leaking detector. This filtering allows police radar frequencies in and out of the detector, while suppressing signals outside of those bands. Because of this bandpass filtering, the ~11 and ~22 GHz signals will be weaker than the Ka harmonic that causes the false alert, since they are outside of the police radar bands while the Ka harmonic is not. In this scenario, the Ka signal is detected first, while the ~11 and/or ~22 Ghz signals are not detected immediately. So, the detector has no way to know to suppress the Ka signal as a false alert, and must report it. This is where the V1 takes things a step further: if a Ka alert is already in progress, and 11/22 GHz harmonically-related signals are detected, it temrinates the alert with a "J".

The "slower response" of some detectors than others isn't due to the detectors waiting on another signal, or slow processing. This is another type of filtering which is implemented in similar but different ways in the different detectors, where a signal must be present for a certain duration of time (usually a number of ms) before the alert is reported.

[venexoz]

Ka false alerts are usually caused by a "junk" detector with a 1st LO in the ~11.xx GHz range producing a harmonic in the police Ka band.

Both the Belscorts and the V1 use similar schemes to determine if the Ka alert is a false: if they receive a Ka alert, they look to see if there is a harmonically-related signal at ~11 GHz and/or ~22 Ghz. With real police radar, these signals would not be present. If they ARE present, the detectors suppress the alert altogether. In some cases, the 11/22 GHz signals are even detected before the Ka alert is, since the Ka alert is the 3rd harmonic it can be weaker than the fundamental @ ~11 GHz or the 2nd harmonic @ ~22 Ghz.

However, sometimes bandpass filtering is implemented in the leaking detector. This filtering allows police radar frequencies in and out of the detector, while suppressing signals outside of those bands. Because of this bandpass filtering, the ~11 and ~22 GHz signals will be weaker than the Ka harmonic that causes the false alert, since they are outside of the police radar bands while the Ka harmonic is not. In this scenario, the Ka signal is detected first, while the ~11 and/or ~22 Ghz signals are not detected immediately. So, the detector has no way to know to suppress the Ka signal as a false alert, and must report it. This is where the V1 takes things a step further: if a Ka alert is already in progress, and 11/22 GHz harmonically-related signals are detected, it temrinates the alert with a "J".

The "slower response" of some detectors than others isn't due to the detectors waiting on another signal, or slow processing. This is another type of filtering which is implemented in similar but different ways in the different detectors, where a signal must be present for a certain duration of time (usually a number of ms) before the alert is reported.

Thanks, you always have the perfect explanation for everything