RX65 KA BAND SELECTION

[cavili]

Dear alls,

Please advise on KA band selection and is there any difference in settings of USA & Int'l. When select to either one does it affect or improve on sensitivity and selectivity.
Any valuable advice is very much appreciated.


Derence
Bel RX65

[Veil Guy]

I recently met up with Craig Peterson on my recent trip to the west when we were conducting our radar detector comparison tests and he specifically recommended that the Rx65 Pro be set to Ka USA.

It appeared to work flawlessly [on Ka] on our 1500+ mile trip throughout NV and AZ.

The Veil Guy 8)

[frog]

I too am curious, as I have seen it posted somewhere that it should be on int. because there is on gun that is commonly used that is outside of the usa settings range.

[Radar Roy]

When you set the Ka to USA, you will be activating "AccuSweep" and detecting only the four Ka frequencies :

There are three Ka frequencies commonly used by police in their radar guns, 33.8 GHz, 34.7 GHz and 35.5 GHz. Some of the Ka band photo radar guns use the additional 34.6 frequency at 5 milliwatts.

Now if you came across an officer that had an out of tune Ka gun and you had your detector on USA, you would be screwed, you would not detect them.

Now the Bel units come with the International mode activated by default.

[cavili]

Just to share my encounter experience this morning. Was travelling along Highway to work and my RX65 alerted KA signal strength of 1 to 2 intermittenly and POP alerted next milli secs. So quickly reduce speed to
within posted speed limit and signal getting stronger between 4 to 5 next moment a Highway Cop drove past from my rear. It give very sufficient time of between 5 to 6 sec to react once alerted. This is a very decent detector, very capable of rear detection and just simply awesome.

PS : Selection on KA band to USA and SWS disabled. Our cops are using MPH Python Series II Gun

[compu44]

I was advised by Bel to not use the USA setting, never know when an officer is going to be using a Stalker frequency hopping radar or be out of calibration.

[RensoreK]

Obviously when set to INTL it takes slightly longer to scan the entire Ka spectrum but how much longer? Would it affect the time of the alert substantially?

[Hessen]

Roy Zegers of ARDS reports that the Bel Rx 65 does very poorly against Ka band.
So if the Ka you're dealing with is similar to the Ka used in Australia you may be in for an unpleasant surprise.
Zegers complaint is the processor in the Bel is too SLOW.
www.australianradar.com.au

[RensoreK]

Roy Zegers of ARDS reports that the Bel Rx 65 does very poorly against Ka band.
So if the Ka you're dealing with is similar to the Ka used in Australia you may be in for an unpleasant surprise.
Zegers complaint is the processor in the Bel is too SLOW.
www.australianradar.com.au

Too answer your question, visit http://www.speedzones.com/immediacy.html as you can see, many of Bels models are in position #1, #2, #4, meaning they react very quickly to the tested, all in less than a second.

Just a few minutes ago I found myself with an LEO using Ka, I changed my Bel from INTL to USA and it still detected him, so I'm assuming his gun was calibrated, but I didn't have a chance to put it in TEC mode (which displays the actual freq of the alert, to verify one of the frequencies the BEL does scan)

[jimbonzzz]

The USA vs International settings on the RX-65 are not about reaction time, but about sensitivity.

Most detectors nowdays sweep all bands within a few hundred milliseconds or less. The "delays" that you see in reporting radar, for example in SML's "Immediacy of Response" test, are not due to a slow sweep rate. These "delays" are actually built into the software on purpose, in order to reduce falsing. This method is widely used and different manufacturers use different schemes here, but for example they might not report a signal unless it is longer than 500ms in duration.

In a scanning receiver, the sensitivity is related to how long the signal is examined. In USA mode, the RX-65 only has to scan the 3 main frequencies used in the USA, instead of the whole 2.6 GHz wide Ka band. This allows the detector to examine them for a longer duration, thus increasing sensitivity (without also reducing response time).

This same idea has been well known in European BEL units, these have "Narrow" modes that only scan the frequencies of interest in order to get better sensitity for detecting weak photo radar. If they set their detectors to "wide" instead of "narrow", the detection range against photo radar is crappy. Maybe some users of these units could chime in...

As far as not being able to detect an out of tune radar unit if set to USA mode, I don't think that would be much of an issue. I am sure that BEL was smart enough to implement a suitable "guardband" around these frequencies, so the guns can be out of tune some and still be detected.

As far as the Stalker that frequency hops, I doubt if they're really out there. You see it referenced at copradar.com and a few other places but that's it. I believe what happened was that when the Stalkers were released in the early 90's, they had to get FCC approval for the new Ka frequency. They got approval for 34.2-35.2, and at this same time I guess there was word that they were working on a frequency hopping unit that could utilize the whole range. I have never seen any hard evidence that that gun ever saw the light of day. Plus, it wouldn't be a good anti-detection feature either since the detectors can scan this whole band. But another term for frequency hopping here is "Spread Spectrum", where the frequency would actually hop hundreds of times a second or more, this would be so fast that the detectors couldn't even pick the signal out of the background noise. We better hope and pray that a Spread Spectrum gun hasn't been in the works since the early 90's, if one of those comes out we'll all be screwed.

Anyway, I recommend that for maximum sensitivity on the RX-65 in the USA, use the USA setting.

Jim

[GTO_04]

I have tested against several Stalkers, both the Dual SL and the ATR handheld, and none of them have frequency hopped. I have a 985 that reads out the frequency so that's how I can tell.

GTO_04

[GTO_04]

Roy Zegers of ARDS reports that the Bel Rx 65 does very poorly against Ka band.
So if the Ka you're dealing with is similar to the Ka used in Australia you may be in for an unpleasant surprise.
Zegers complaint is the processor in the Bel is too SLOW.
www.australianradar.com.au

I am more inclined to believe Roy Zegers than the simplistic SML test.

I tested my 985 against a V1 (1.7 version) and the V1 spanked it in response time on Ka band. Not even close!

GTO_04

[francescolodico]

How about in Quebec Canada....I read all of you on which is better but you guys are all in the states. How about in quebec Canada? Can anyone give me a suggestion to which mode (INTERNATIONAL or U.S.A) for Ka detection would be best?

Thanks again...waiting for a response...
Frank

[stealthJamal]

I believe Quebec and other Canadian provinces use the same equipment availble to the USA. So Ka USA should really be called Ka North America.

[vw242]

Was latest GOL using the Intl or USA??

[happya$$]

Was latest GOL using the Intl or USA??

USA

[francescolodico]

Just to share my encounter experience this morning. Was travelling along Highway to work and my RX65 alerted KA signal strength of 1 to 2 intermittenly and POP alerted next milli secs. So quickly reduce speed to
within posted speed limit and signal getting stronger between 4 to 5 next moment a Highway Cop drove past from my rear. It give very sufficient time of between 5 to 6 sec to react once alerted. This is a very decent detector, very capable of rear detection and just simply awesome.

PS : Selection on KA band to USA and SWS disabled. Our cops are using MPH Python Series II Gun

Where is your detector placed? Top windshield? Middle or dash??

[nvr2fast]

Was latest GOL using the Intl or USA??

USA

Since the X50 scans the entire frequency (no "USA" mode) and the RX65 was set to special "USA" mode, could this attribute cause the difference in performance?!

[jimbonzzz]

Since the X50 scans the entire frequency (no "USA" mode) and the RX65 was set to special "USA" mode, could this attribute cause the difference in performance?!

It is definitely a possibility, and it should be tested.
There are other possible differences between the RX65 and X50 though...

[nvr2fast]

Since the X50 scans the entire frequency (no "USA" mode) and the RX65 was set to special "USA" mode, could this attribute cause the difference in performance?!

It is definitely a possibility, and it should be tested.
There are other possible differences between the RX65 and X50 though...

Not in the horn antenna now though... the production of the cast iron was merged. Open one of each of the latest RX65 and X50, and you'll see what I mean. The horn antenna is now the same, so the "physical" sensitivity of the units should be the same. Only thing left is the software side. But it would be good to confirm the hardware horn antenna is the same first, to make that a starting point of showing the differences.

[jimbonzzz]

So they started using the new horn in the X50 as well? Makes me wonder about the other units like the V995 etc. This might make it a little more difficult to compare the performance of these units. Would be nice to get one with each type of horn and compare the performance, I would also wonder if there is much of an advantage to selling an older unit and buying one with the newer horn. Do you have any pictures of the internals of the new X50?

Jim

[PHILBERT]

Hello ALL,

I'm new here. I am very happy to have found this forum because I see good interesting people and great info. Thanks to Roy for all the great info he has put on the web!

I've never really gone "all out" on the whole radar/lidar countermeasure thing before. To be honest, I don't even speed anymore UNLESS I have to get around some "logjams" here in South Florida. I have had three detectors in my day and none of them were that good. The best I had was an old 80's RS model with an analog "S" meter that could really hear very far away. The meter was a good indicator too! The Unidens I had were trash. Falsed more than anything.

Anyway, I just purchased a new Kia Sedona mini-van and was really exited with the overhead console until I learned it did not have a compass. DOH! Nice van and a compass can be added, so I looked around and found an RS 22-1699 Detector with a digital compass on a 50% closeout. I said "what the heck" and proceeded to test the compass. I calibrated it and ran it with Street Atlas 2005 and the LT-20 GPS NAV. The compass is dead nuts on. Very good indeed. Mission accomplished! But what about this "detector" thingy? Looks like it works fairly good, but how good? What am I missing, and why do I get occasional full-scale Ka alerts? Some VG2 alerts too???

I hit the net and learned all that I could from the top sources (including Roy's great presentations). Only one test site made brief mention of this unit and put it down compared to the 22-1697 they tested. It said they listed the results in their "Full Report", but the 1699 is not one of the units tested in "the report". $15 for this? NOT! So, now how do I test this? The idea grew in my mind that I had to get the RX65. I always dreamed of one day owning that Escort (back in the 80's), but never went for it. All things being said, the RX65 is a great package with excellent test results, so I nabbed one.

Got it new for $279! Had the distributor advise me on where to get one. The price was a nice surprise! I had it programmed up in no time and fell in love with that "Threat Display". 1-9 signal readings on each band! Wow! this thing is so cool! OK, the usual door opener signals, but every legit signal is right there...or is it? I thought it was until I tested both my RS 1699 and RX65 together. Why was the 1699 picking up those trooper cars when the RX65 was dead quiet!? I started thinking about this "International Mode" vs "USA Mode" selection. I finally found some answers here. (the 3 frequency thing) I promptly switched to International Mode. I also put it in Tech Display to read the frequency on the RX65. Well lookey here...I am seeing some "off note" frequencies here in FL! Off enough to not be scanned in USA mode. MISSED ALERTS! Use INTERNATIONAL MODE! Now I know. No harm done...I don't speed. I will also note that the troopers like instant on. Only a couple were driving around in constant mode. Watch out down here!

Why get such a top line detector? I like to play radio. I'm a HAM. I worked in commercial radio and now work on cell sites. I love test equipment and did R&D in the RF field. I just gotta know how this thing works and how it was engineered. It's early yet, but I see some areas Bel could improve on. More on that when I have been using it for a while.

So, what about that crap RS detector? It's not too bad. Really! The range is fairly good. Falses? YES! Most from other detectors INCLUDING the RX65. The two were jamming each other and needed to be kept apart in my truck. I had to lock out everything but Ka band on the RX65 to keep the 1699 from falsing. The 1699 HAS POP TOO! That was a surprise. The only POP alerts (full-scale quick alerts) I got were from other detectors. My RX65 behaves very well on POP, but the RS caused it to POP when it received a K band signal. Strange! I would not put 100% trust into the RS unit, but it does work and has a very good feature set. I like the alerts better than the RX65. Even the voice alert sounds better. And let’s not forget the compass. It's great. I can't tell you how many times I drive the wrong direction on rainy days and nights in areas I'm not familiar with. And FL is a N,S,E,W state! I wish BEL would have a simple two-letter compass!

What do I do with this RX65 now? I use it in the WORK TRUCK! It's FUN! All this time I was missing what was out there. I had no idea how concealed some of these guys were! And get a load of this...My Sheriff's Dept is still using X BAND in some vehicles. YES...X BAND! 10.525 confirmed! Not surprising since they still use these 25+ YO S&W light bars. :roll:


PHIL 8)

[amoney]

Here in south Florida...

I have Accusweep DISABLED, for the same reason PHILBERT noted, the Ka guns used here by LEO's reported by TECH mode are "off tune", so although my Bel would be a tad quicker by enableing Accusweep, I would possibly then get NO alerts! I only came across one BEE III @ 33.8 reported, but then again a recent comparison noted that the TECH displays can report different freq for same bogie (when a x65 and x50 where both displaying the freq for the same bogie the freq differed by 10 mhz, so ???????????????)

A VERY INTERESTING THOUGHT OCCURED, I NOTICED SOMEONE SAID THEY HAVE SWS TURNED OFF!

Would that help increase better detection, so as the detector does not have to waste time serching for that frequency?! I think I am going to do that as well, since obviously their is no such thing (SWS).

[PHILBERT]

I wondered about the possibility of an inaccurate reading on the Tech Display myself. After "staking out" some well known trap locations, I'm beginning to see consistent results. (I hide in the brush near the trap areas...hehehe...they don't know I'm there!) The frequency displayed is the same unless there is more than one device in use. The only "drift" I have seen is from door openers. That could have been multiple door devices being picked up. Here is a list of freqs I have recorded from VALID Ka radar so far (need more time/data).

34.750
34.688
34.706
34.700 (known channel)

We do not know how wide the RX65 looks on each channel on USA mode. I'm not trusting USA Mode.

On the SWS thing, I have seen this in use. My first encounter was the Delaware Bridge toll plaza (I think that is where I heard/saw it...somewhere up there). I bet the scan time is not an issue. I will keep SWS on. Should be interesting to see how much is out there.

What happened to the SWS web links? Has SWS gone bankrupt? :?

Philbert OUT ~

[jimbonzzz]

Hi Philbert, welcome to the board...
So you're a ham eh? There's a few of us around on the board, such as:
KC7YCM: Reyer, Roy R. For a radar detector, I recommend the one designed by W8MM.

As far as tech mode goes, although seeing the decimal out to three places kind of misleads you into thinking you have that kind of accuracy, you really don't. From the testing I did (http://www.radardetector.net/viewtopic.php?t=348) Spec mode is only accurate to about 15-18 MHz (on K band at least), so using it to attempt to determine the amount of "drift" of different radar might not tell you as much as you think.

For USA mode I am sure that they designed the units to take into account a suitable guard band so that "normal" off-frequency units are not missed. This would be no different that what they and the other manufacturers do with X or K band, and I don't think they're missing too many alerts there.

Jim

[PHILBERT]

Jim,

Hello!, and thank you. Sounds like you are one of the techies around here. I spotted it the other day when you were talking about the V1 PoP mode and the "J" display. I give Mike credit for that feature with the harmonic searching, but I hate to be alerted to ANY "Junk" signals at all. In my opinion, all these devices need better user controls.

So, you like the V1 better? I have read allot about it. I have a friend who has one. I guess this one design has been tweaked allot over the years. It is very capable, but I don't like the display. I need more information. What I do like is the total dedication to ONE unit over a long production life. I don't want to keep buying the "latest and greatest" new detector every year or two. I will give the V1 that. The V1 SML test results show 0 out of 3 Ka POP hits, and that is a what swung me towards the RX65 (that and the display features). I also read in several places about the constant falsing. Is it really falsing, or is it just so sensitive to any "mouse fart" that is out there? My friend’s is always going off, and I hated listening to it. The RX65 is great in "Threat Display" mode. I like the 1-9 signal readout on each band allot. I also like the Ku band as I heard it will become available to the US in 06. I would be interested in looking at a V2 if one came out...that is, if it had much more information on the display AND better user control like the Belscort's do.

What I really want to see in a top line detector is MORE user control. For example, the RX65 has great threshold options for X band, but not K band. Heck...I get more K band automatic door radar than X band. Why no "City Mode" options for K band? What IS cool about the RX65 is how the X band signal still shows in city mode even though it is below the alarm threshold. Why not have that on K band too? How about a few user memory modes where you could set everything just the way you want it for different environments. Things like voice announcement without the alarm sounds until each band meets the thresholds you set. At least we can control the bands and some options, but I would really like to see more in user control.

As far as your cool K band gunplexer tuning test, I am getting different frequency readouts than you do. Were you using version 3.X? I have 4.5 and I will keep collecting frequency numbers until I detect the pattern. How do these things really work? Do the "scan" like a scanner would in a "chain search" mode? Are the freqs you tested merely just "steps" like scanners have? Is it possible that you might get less range when you are between frequency steps because of bandpass limits for each channel (selectivity)? If I had a generator that went that high, I would do these tests myself. I would also measure sensitivity across the bands. I have seen enough to know the tech display is not what is drifting here. It's more likely the transmitters going from a cold state to warm. Someday they might actually use GPS as a time base and it might be also used for location evidence as well. I'm surprised they have not done that yet. GPS is CHEAP these days! So, I have much more to learn. I'm sure these companies do not want to say too much about how it works. That may be the reason there is SO LITTLE information provided about "USA Mode". All I can say is that I did NOT get alerted in that mode when my cheapy RS 22-1699 gave me plenty of notice. This happened THREE times in one day. Once I switched to International Mode, the RX65 got them all. We just don't know how "wide" the RX65 looks on USA Mode channels. From my quick tests, not wide enough!

As far as POP falses go, I understand that very well. Even scanners (I'm into them big time) throw out quick mixed images when they scan through the programmed channels. I see some detectors do too (RX65 as well). Some may leak more than others. No way to stop those quick "blips" that trip the "POP". Better safe than sorry IMHO. You do have the option to turn it off. I do not have much of a problem with that. It would be nice if the FCC had tighter controls on the industry. I read a little about some detectors interfering with other services and what motions the FCC was taking to clamp down on "garbage detectors". As I remember from my EMI/RFI testing days, the spec is more lose the higher you go up the spectrum. Maybe TOO lose! Than again, enforcement is almost non-existent. Look at the HUGE amounts of power line noise that nearly wipes out the HF bands these days. Florida is nothing but power line noise!

I have to run now, but thanks for the welcome. I think we will be talking much more in the coming weeks. :wink:


Phil OUT~

[compu44]

Phil -
If you notice some sort of consistant pattern as to certain cruisers that won't cause an alert in USA mode - see what the frequency readout is. Also, please try it with the USA mode on without the radioshack detector running. Running certain detectors together can cause problems, and I wonder if, due to the quicker scan with the USA mode, the filtering is acting differently in the RX65 and filtering out too much when it senses the radioshack unit's interference.

Welcome to the forum.

[jimbonzzz]

Jim,

Hello!, and thank you. Sounds like you are one of the techies around here. I spotted it the other day when you were talking about the V1 PoP mode and the "J" display. I give Mike credit for that feature with the harmonic searching, but I hate to be alerted to ANY "Junk" signals at all. In my opinion, all these devices need better user controls.

Yeah I guess I am one of the techies around here, but we have some others around who are the real experts that I learned from. It is great to have yet another ham on the board, I think that many hams are able to gain an understanding of the technical aspects of these units a lot easier than many of those in the general public.

The same harmonic scheme is used by most of the detector manufacturers (at least the high end ones) to completely block out falses from other detectors. Same with the V1: If it saw the harmonic at the same time or even before the radar, the alert would be suppressed completely. The thing is, that sometimes the harmonic isn't immediately detectable at the same time as the police radar frequency, hence the "J" feature. Valentine originally implemented the "J" feature in order to have better POP protection without having falses that were left unresolved, but I believe that this is now a standard thing across most of the Ka range, not just the MPH 33.8 GHz freq. If it sees the radar, it needs to alert to it immediately since it could be police radar and not "wait" to see if a harmonic is detected later. But, if it did see a harmonic later, it J's out the alert letting you know that it was indeed a flase and not police radar. There have been some complaints though about the V1 J'ing out real alerts at close range when it gets overloaded.



So, you like the V1 better? I have read allot about it. I have a friend who has one. I guess this one design has been tweaked allot over the years. It is very capable, but I don't like the display. I need more information. What I do like is the total dedication to ONE unit over a long production life. I don't want to keep buying the "latest and greatest" new detector every year or two. I will give the V1 that. The V1 SML test results show 0 out of 3 Ka POP hits, and that is a what swung me towards the RX65 (that and the display features). I also read in several places about the constant falsing. Is it really falsing, or is it just so sensitive to any "mouse fart" that is out there? My friend’s is always going off, and I hated listening to it. The RX65 is great in "Threat Display" mode. I like the 1-9 signal readout on each band allot. I also like the Ku band as I heard it will become available to the US in 06. I would be interested in looking at a V2 if one came out...that is, if it had much more information on the display AND better user control like the Belscort's do.

Yes, I do like the V1 better. But I like a lot of the other detectors too, I just like messing with them in general I guess. Would I recommend the V1 for an average driver who rarely goes more than 5 over the limit? Probably not, as others have said that would be like swatting a fly with a nuclear bomb. But for the driving enthisiast with a high-performance vehicle who likes to see what it can do, I would definitely recommend a V1, and I think every "detector enthusiast" should at least try it out.

As far as SML's POP test, it's hard to say exactly what happened so I won't try to speculate. There were a LOT of questions raised about some of this year's SML test results. That is one of the reasons that some of us amateurs here on the board got together and formed our own test team. In our "Guys of LIDAR" tests which included me and some of the other "amateurs" on the board, the V1 actually did the best as far as detecting POP. If you haven't see the results yet check out http://www.guysoflidar.com

As far as the falsing, since the V1 has both the front and rear antenna, logically you could expect twice the falsing. And the V1 was also more sensitive for both X and K band in our GOL tests, so that could contribute as well. That said, I have heard multiple reports that have said that the V1 version 3.825 is very quiet as far as falses go, even going so far to say that it is quieter than then RX-65 and X50. I cannot confirm this though because I have the 3.818 and haven't bothered to get it upgraded yet.



What I really want to see in a top line detector is MORE user control. For example, the RX65 has great threshold options for X band, but not K band. Heck...I get more K band automatic door radar than X band. Why no "City Mode" options for K band? What IS cool about the RX65 is how the X band signal still shows in city mode even though it is below the alarm threshold. Why not have that on K band too? How about a few user memory modes where you could set everything just the way you want it for different environments. Things like voice announcement without the alarm sounds until each band meets the thresholds you set. At least we can control the bands and some options, but I would really like to see more in user control.

I think that a LOT of people here on the board want more user control. Problem is they seem to be designing for the average joe who doesnt understand how most of this stuff really works, he just wants it to beep when a cop is around.



As far as your cool K band gunplexer tuning test, I am getting different frequency readouts than you do. Were you using version 3.X? I have 4.5 and I will keep collecting frequency numbers until I detect the pattern. How do these things really work? Do the "scan" like a scanner would in a "chain search" mode? Are the freqs you tested merely just "steps" like scanners have? Is it possible that you might get less range when you are between frequency steps because of bandpass limits for each channel (selectivity)? If I had a generator that went that high, I would do these tests myself. I would also measure sensitivity across the bands. I have seen enough to know the tech display is not what is drifting here. It's more likely the transmitters going from a cold state to warm.

I have seen different frequency numbers posted for K-band, so I don't know exactly what is going on. But with mine, it will only display the frequencies I posted in my little test. 15-18 Mhz resolutions is really quite good though for what it is, since it isn't a $1000 freq counter :lol:

I don't know the full details on how these work, and the schemes do vary. They are basically scanning receivers, but they don't utilize frequency steps in the same sense as scanners. Detectors will usually have different "sweep" and "Park" rates. From what I understand, some have more of a constant sweep (BEL, Escort??), some have a constant sweep until they see a signal of interest, and then they'll "park" on that frequency to get a closer look (Whistler, Valentine??), and some will "park" on certain frequencies as part of their normal scanning (Cobra??). To a point, sensitivity in the detectors is actually related to the amount of time the signal is examined.



Someday they might actually use GPS as a time base and it might be also used for location evidence as well. I'm surprised they have not done that yet. GPS is CHEAP these days! So, I have much more to learn. I'm sure these companies do not want to say too much about how it works. That may be the reason there is SO LITTLE information provided about "USA Mode". All I can say is that I did NOT get alerted in that mode when my cheapy RS 22-1699 gave me plenty of notice. This happened THREE times in one day. Once I switched to International Mode, the RX65 got them all. We just don't know how "wide" the RX65 looks on USA Mode channels. From my quick tests, not wide enough!

Escort holds a patent on a GPS enabled detector, whether it will use it as a time base I don't know, but the idea is to store known false alert locations for future filtering like the Uniden GPSRD did. Who knows if/when we'll see anything from them using this.

Unfortunately, they really don't provide us with much info, as they assume that the general public is uneducated about just how these things work. Same type of thing: they seem to be designing for the average joe who doesn't understand how most of this stuff really works and doesn't really care either, he just wants it to beep when a cop is around.

Like someone else said, don't run two detectors together. You'll hear some people debate on this, but there are some very good technical reasons why this should not be done, and since you're a ham I would expect that you could understand the reasons more than most people :) Running two detectors together can cause one unit to actually block out alerts in the other one. I did a good write-up on it here:
http://www.radardetector.net/viewtopic.php?t=3983

I have been told that a prominent engineer in the industry has confirmed that this write-up is 99% correct about the reasons detectors should not be run together. Not quite perfect, I must admit ;)

I have since found even more reasons why this should not be done: as above, some of the detectors will see the interference and "park" on the frequency in order to get a better look, even if it determines that it isn't polcie radar and doesn't alert. This will have the effect of slowing down the overall sweep, reducing their effectiveness to real radar (especially POP) as long as they are in the vicinity of the other detector.

BTW (shameless plug) if you use any Yaesu HTs check out my webpage at http://www.kc8unj.com

Jim

[compu44]

Hey Jimbonzzz - You ever heard of these?

http://www.policeradar.com/SpeedTrak_Radar.htm

You think they'd be on one of the standard three frequencies?

[jimbonzzz]

Yeah, they're on the IACP approval list. I've looked into them before, but could never find much info. As far as what frequency, I don't know about that for sure either, I didn't find anything on McCoy's on the FCC database. But I suspect that they might be manufactured by Decatur...

Jim

[compu44]

Yeah, they're on the IACP approval list. I've looked into them before, but could never find much info. As far as what frequency, I don't know about that for sure either, I didn't find anything on McCoy's on the FCC database. But I suspect that they might be manufactured by Decatur...

Jim

I tried searching for patents and couldn't find anything either.

[PHILBERT]

compu44,

Thanks for the welcome. :) This might be impossible to check. I would need two RX65's running at the same time...One in USA and one in International. As Jim pointed out, they will most likely interfere with each other, so this most likely would not work. The real problem is that you can't tell when one of these guys has the radar on or not, so you think you missed something when maybe you didn't. Doing a "turn-around" after switching modes would be hard, as the exits on "the I" are far apart.

I'll think about it a bit. Maybe I can come up with an idea. Until then, I plan on writing down the frequencies I encounter. :wink:

Jim,

That is ALL solid stuff! Only one thing I question. Are the detectors really looking for harmonics? Transmitters generate harmonics, but receivers generate mixed images. Maybe the detectors are looking for harmonics to validate REAL radar sources. ???

I believe the two detectors were really messing with each other. Now that you pointed it out, I can see how one would cause the other to possibly divert attention elsewhere even though it did not go into alarm. (like watching false signals to see if they are real) The intelligence software used to screen falses must be somewhat complex in the high-end units. Makes sense.

How about that "Autoscan" mode? I tried it. It blocked some X band door openers up to the point of being almost on top of them. I had no indication at all up to that point. At least in city mode you get a signal indication before you get a strong enough signal to trigger the alarm. Maybe that is why Roy suggests Highway or City modes.

I also understand the KISS mode for the average user. I have done enough beta testing to know that complaints go up dramatically when you give users too much rope to hang themselves. USA mode may be a small example of that. No company wants to increase it's customer service call rate by confusing customers. I would like to see things a little more flexible though. Personally, I would like to see the ability to set thresholds on each band and see the signal on threat mode prior to sounding a full alert. Better yet, I would like to hear a voice announcement when the signal appears under the threshold(s). You can always have the "default" settings that the manufacturer recommends.

I have to run now, but thanks for all the information! It's good stuff and very interesting. I can now understand the difference between the low-end units and high-end gear. My RS 22-1699 is not bad at range. POP? Too many falses. VG2? It goes off in certain spots. I can't say why yet, but I think it's picking up some garbage like computer EMI. Being a ham, I'm well aware of what a mess the spectrum is these days with all of the "Part 15" radiators out there. The FCC has let the spectrum become a cesspool!

Phil

[jimbonzzz]

That is ALL solid stuff! Only one thing I question. Are the detectors really looking for harmonics? Transmitters generate harmonics, but receivers generate mixed images. Maybe the detectors are looking for harmonics to validate REAL radar sources. ???

Yeah...the harmonics come from the leaking local oscillators in some of the detectors, which can generate false alerts on Ka band. These will end up leaking out the antenna through the first mixer. The biggest culprit is the first LO, but mixer products (like you mentioned) can and do end up leaking and doing the same thing. Some units leak much more than others This is also how the Spectre RDD detects the units, and so far there aren't any detectors that are 100% leak free.

Probably the oldest example is the 11.558 Ghz LO. The third harmonic is in the Ka band: 11.558 x 3 = 34.674 GHz. So, the detectors will look for the second harmonic at 23.116 GHz. If it sees that, it knows the Ka radar was produced from the leaking oscillator of another detector and not real police radar, and will suppress the alert.

Notice that the second harmonic is just below the K Band at 23.116 GHz. The reason this is sometimes not detected immediately is that the bandpass filtering for K-Band in the leaking detector will attenuate this some.

That is but one example, there are countless oscillator schemes used by different manufacturers that will generate harmonic falses in the Ka band, and the detectors must take those into account to suppress those alerts. Some will generically look to see if there is a signal with a harmonic relationship to the detected signal, for example it might look at 1/3 or 2/3 of the interfering signal. None of the detectors use harmonics to validate real police radar sources that I know of.

Jim

[compu44]

I little new info on the guardband question:

Apparently the PNI radar detectors run in a mode similar to Bel's USA mode all the time. They scan

33.7 to 33.9 - MPH products
34.2 to 34.4 - TMT-6F photo radar
34.6 to 35.0 - Stalker products (center @ 34.700), PR-100 photo radar (center @ 34.600), Kustom Eagle AU model (34.9)
35.4 to 35.6 GHz - Decatur/Kustom products

They are running the +/- 100MHz thing, all the time, so apparently they feel safe with it.

[PHILBERT]

"They feel safe with it"

With that many windows I might feel safe. After doing some tests with my RX65 in USA mode, I'm convinced it only scans THREE areas and nothing else. I base this on the number of legit hits AND many many false hits (some self generated).

USA mode falses more (don't need that). The real question is will it detect much further to make it beneficial. :?:

GOL - Can you test this?

PS - Thanks for sharing!

[RensoreK]

A GoL test about this would be very beneficial. Maybe someone can generate the frequencies to test them out :?:

[ES13Raven]

USA Mode patent?

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/netahtml/search-bool.html&r=33&f=G&l=50&co1=AND&d=ptxt&s1=5305007&OS=5305007&RS=5305007

[jimbonzzz]

USA Mode patent?

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/netahtml/search-bool.html&r=33&f=G&l=50&co1=AND&d=ptxt&s1=5305007&OS=5305007&RS=5305007

I am a curious: what would make you think that?

[ES13Raven]

I skimmed through it real quick. I saw something about scanning the wide-band Ka and the narrow-band Ka. Am I way off?

[compu44]

Jim - question in regards to the 985 GOL test. I know that the RX65 was run in USA mode for your last test. Was the 985 run in AccuSweep?

[jimbonzzz]

Jim - question in regards to the 985 GOL test. I know that the RX65 was run in USA mode for your last test. Was the 985 run in AccuSweep?

Good question...
I'm not sure, the person to ask I think would be Boomerman.

Jim

[boomerman]

I think the Bel 985 that was at the test was Outrun's.
It was not mine. so I can not answer that.

[jimbonzzz]

Oh sorry man :oops:

[outrun]

To be honest I am not sure if that feature was on or not. I was going to go back and see what was set but I am sure I have reset it since then.