Excessive K band falsing on NR-DSP

HankLloydRight

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Hello,
I have a new ALP with F+R NR-DSP install and took it out for a long drive today (3 hours). I configured the ALP (HW4) unit according to Vortex's setup guide with K-Filter on. Starting in New Haven area all the way into New Jersey, I was getting CONSTANT K band alerts (see logs below).
I pulled over three or four times to check and reload/download the correct configuration, but it was useless, until the last time I pulled over and disabled K band all together at 1:12pm. Finally, I got some peace!
I bought the ALP+NR system to improve on the my Bel STiR+ system because everyone raved about how better the K band falsing was on NR-DSP, but at least today, the K band alerts were between constant and every minute or so. It was impossible to listen to any podcasts with the constant interruptions. Is this normal for the greater NYC area? What's the risk of just running without K band at all? I realize I'm new at this and something's wrong (I hope), but what could it possibly be?
Thanks.




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Too3zln

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What vehicle do you drive? Perhaps a Honda?
 

Flonase

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The NR-DSP can be made quite quiet on K band, but you have to do a little configuration work to get there. The band segmentation was revised to allow you to slice out the common Honda/Acura (24.200, plus or minus) and GM (24.167, plus or minus) bands. Might have the car makes mixed up, but you clearly know what I'm talking about. Anyway, try turning off the segments centered on those two frequencies.

Then, if you see a specific vehicle in your area that still trips an alert frequently, you can use one of fifteen ARF (Adjustable Radar Filter IIRC) slots to just filter that out as well. I'll see if I can dig up the link tomorrow if no one else points you in the right direction tonight. I do know that the feature was announced / described in the ALP subforum, instead of the NetRadar one...

Finally, for stationary falses, you can use AutoLearn to set filters for them using the app.

Hope this helps.
 

HankLloydRight

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What vehicle do you drive? Perhaps a Honda?

Tesla.

The NR-DSP can be made quite quiet on K band, but you have to do a little configuration work to get there. The band segmentation was revised to allow you to slice out the common Honda/Acura (24.200, plus or minus) and GM (24.167, plus or minus) bands. Might have the car makes mixed up, but you clearly know what I'm talking about. Anyway, try turning off the segments centered on those two frequencies.

Then, if you see a specific vehicle in your area that still trips an alert frequently, you can use one of fifteen ARF (Adjustable Radar Filter IIRC) slots to just filter that out as well. I'll see if I can dig up the link tomorrow if no one else points you in the right direction tonight. I do know that the feature was announced / described in the ALP subforum, instead of the NetRadar one...

Finally, for stationary falses, you can use AutoLearn to set filters for them using the app.

Hope this helps.

Thanks. I've already been locking out stationary K radars. All of the above alerts were on the Merritt, 287, GPS, NJTP.

In heavy traffic,I have no idea what cars would be triggering the K bands.

I'll look into the ARF tomorrow.
 

G37X Jockey

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One possibility could be that your route is lined with traffic monitoring K band transmitters, which will trigger a K alert every mile. IF this is the case, turn on the TMF filter in the K band settings.
 

midd

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Is MRCD enabled? That will create lots of false alerts on the DSP with K band being turned on as well.

NJ state highways don't use traffic monitoring transmitters, only cameras.
 
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TurboDriver

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. @HankLloydRight

Those totally look like Honda / Pacifica / Jeep and a stray GM falses. Definitely look at ALF, it is like a custom K Block, you need the Bluetooth App to do this. I have a thread about ALF here somewhere, it is wonderful. I love my NR DSP, quietest unit I have.

Do not segment K band, with ALF I can run K wide no problems.

Once ALF is set in App the CPU remembers the settings even without App on.
 
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HankLloydRight

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Thanks for all the help, folks.

One possibility could be that your route is lined with traffic monitoring K band transmitters, which will trigger a K alert every mile. IF this is the case, turn on the TMF filter in the K band settings.

Wouldn't this be a "well known" thing in the greater NYC area along the main routes I drove across three states? (Merritt Parkway, 287, Tappan Zee bridge, GSP and NJTP)?

Is MRCD enabled? That will create lots of false alerts on the DSP with K band being turned on as well.

NJ state highways don't use traffic monitoring transmitters, only cameras.

MRCD is not enabled.

OK, here's the original thread where Tom announced ARF on HW4 CPUs. It was over in the ALP subforum.

There's another thread dedicated to ARF here.

Awesome, reading up now. Thank you. Hopefully my return trip on Monday will better. I was excited to take my first road trip with ALP+NR (and Highway Radar), but after two hours of this, I was almost pulling my hair out!
 

Flonase

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I went through your data - thanks for posting those screenshots, by the way! There were 9 distinct data sets (looks like screenshots 5 and 6 are duplicates). By my count, here's how the alerts broke down:

Alert TypeNumber% of K Total
K3 (24.165-24.180)3942%
K5 (24.195-24.205)3639%
Other K1819%

So, turning off the K3 and K5 segments / turning on these "notch filters" would cut out 81% of your K-band alerts. You didn't mention any legit K-band hits, so I think it'd be a no-brainer to turn off K segments 3 and 5.

Then, you'd want to set up some ARFs. Here's the breakdown of the "Other K" alerts you received.

FrequencyNumber
24.16012
24.1523
24.1231
24.1171
24.0681

Be on the alert, and next time you have a 24.160 BSM alert, capture it as an ARF frequency. That would cut out another 13% of your K-band alerts. Between that one ARF filter and K segments 3 and 5, that would eliminate 94% of the K-band alerts you've been getting.

Are the other stragglers stationary sources? Real obscure BSM systems? K segments 3 and 5 and a single ARF filter would make a massive difference, at least.
 

HankLloydRight

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Wow, you are a god among men! I was going to try and extract all that data myself to see what freqs were most common. I can't thank you enough for saving me all that work. But then you added all the subject matter expertise I don't have in order to make your recommendations, so again, wow. Thank you.

Side question: Why aren't BSM frequencies fixed and known? Do they fluctuate across wide bands making it impossible to know which car makes use which frequencies?

edit: Yes, I only have 9 screenshots, sorry for the dup.
 

Flonase

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Side question: Why aren't BSM frequencies fixed and known? Do they fluctuate across wide bands making it impossible to know which car makes use which frequencies?

I can only speculate. The common ones are known. Manufacturers probably contract with vendors to provide a system for them, and have it tweaked to their specifications - kind of like the all-wheel drive systems that Haldex provides to various automakers. A Haldex system in an Audi will be different from a Haldex system in a Volvo, for example.
 

thebravo

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Wow, you are a god among men! I was going to try and extract all that data myself to see what freqs were most common. I can't thank you enough for saving me all that work. But then you added all the subject matter expertise I don't have in order to make your recommendations, so again, wow. Thank you.

Side question: Why aren't BSM frequencies fixed and known? Do they fluctuate across wide bands making it impossible to know which car makes use which frequencies?

edit: Yes, I only have 9 screenshots, sorry for the dup.
BSM are most common in a few small frequency ranges, usually about +/- 0.005 of a center frequency, many of them without doing advanced signal processing (like theia) look like normal kband so most rd's struggle with filtering them. Legit police radar can operate in those same frequency ranges so just silencing everything in that range introduces some risk, using ARF or features like the block weak setting on the R7 which blocks lower level intensity kband in those ranges is a good option for blocking out weak BSM but allowing stronger legit kband in those ranges to alert so you miss any real threats.

Once you get a little tweaking done on NR it should be pretty quiet for you, you can also play with sensitivity using the yellow and red options as well for times when you are in congested areas and I and is still plaguing you.
 

HankLloydRight

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I guess it's time to set up profiles. ;)

As a noob, how can I tell if a K band alert is a BSM or a real alert? Are there any telltale signs it's definitely a BSM?
 

Flonase

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BSM are most common in a few small frequency ranges, usually about +/- 0.005 of a center frequency, many of them without doing advanced signal processing (like theia) look like normal kband so most rd's struggle with filtering them. Legit police radar can operate in those same frequency ranges so just silencing everything in that range introduces some risk, using ARF or features like the block weak setting on the R7 which blocks lower level intensity kband in those ranges is a good option for blocking out weak BSM but allowing stronger legit kband in those ranges to alert so you miss any real threats.
EXCELLENT point about ARF blocking only weaker BSM-level signals.

Wouldn't it be great to be able to see the ARFs you have already set? I wish I could see mine.
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I guess it's time to set up profiles. ;)

As a noob, how can I tell if a K band alert is a BSM or a real alert? Are there any telltale signs it's definitely a BSM?
If you're in a metro area where K band is not used, it's a BSM or stationary false :p

Seriously though, that's kind of the principle I used when I set up my profiles. A is "All Threats", with everything turned on. I use it to set up lockouts, primarily. C is "City", where I have K and X bands turned completely off. And then B is "Blend", where I have K turned on, but certain segments turned off, and sensitivity turned down to Yellow.
 
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HankLloydRight

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Has anyone done a USA heat map of where K band is actively being used for speed enforcement?
 

Flonase

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Has anyone done a USA heat map of where K band is actively being used for speed enforcement?
It's not exactly a heat map, but check out the RDFGS subforum.

A better bet, if you know where you'll be traveling, would be to just ask in the Road Trips forum and in the appropriate regional subforum. You'll get anecdotal, but current, information.
 
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NorEaster18

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Has anyone done a USA heat map of where K band is actively being used for speed enforcement?
I'll speak for your area. You won't see much K band in CT nowadays. In the last three years, I have personally encountered it from Wallingford, Redding, Southbury, and Naugatuck local PD. I rarely venture up into Litchfield County, so I can't really speak for that area. But I regularly drive through the rest of the state, and I can confirm that lidar and Ka 34.7 are going to be your main threats.

Venture up to MA or VT and you'll see a whole lot of K band from locals and state police. It's more common than Ka in both states, at least from my experience. It pops up from RI and upstate NY locals as well, but not as common as Ka band.

Speaking on a country-wide basis, it's pretty safe to assume that it's used everywhere in some capacity. There's very, very few locations where it's safe to completely disable K band (southern California is one area that comes to mind).
 

Flonase

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Speaking on a country-wide basis, it's pretty safe to assume that it's used everywhere in some capacity. There's very, very few locations where it's safe to completely disable K band (southern California is one area that comes to mind).
The Twin Cities metro area is an island of Ka-only (with increasing lidar as well). Not that you’d be likely to drive here... 😜
 

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