Peak and Tune Radar Detector?

[o2bad455]

Knowing all too well that radar detectors are mass production, what can be done to optimize a modern detector if one has the time and patience, and is willing to track down the right tools? Since most of the operation is defined by firmware, I'll start by ignoring that and considering just the horn. Can anything be done to improve the horn's efficiency, such as smoothing and blending the top to bottom seam, for example? Polishing the inside? Camfering the lip? Or is any change more likely to hurt than help?

[languy99]

I always though that if the horn was bigger the sensitivity would go up. I'm not sure if this is true or not because I'm not an expert. Maybe someone who does know can answer my question.

[jerry540i]

Not much you can do with today's modern detectors. I highly doubt polishing the horn will do anything.

I remember detectors back in the 80's that had a small fine tuning screw located at the back of the horn. If you knew what you were doing, you could "adjust" your own detector.

As for today, as mentioned previously, most of the changes are software driven.

J/

[MEM-TEK]

Polishing the horn or smoothing its seams will not have any effect since radar waves are absolutely huge compared to light waves. Smoothing the edges on the ridge wave guide will cause performance to plummet. In other words, there is nothing you can do the horn itself since it is already an optimal design which is matched to the LO chamber.

Bel and Escort hold patents on using circuitry which automatically calibrates the radar detector for optimal performance every time it is powered up and periodically thereafter.

:)

[Stealth Stalker]

LOL@"polishing the horn"

Is that what you crazy kids are calling it these days? :lol:

[corkguykev]

LOL@"polishing the horn"

Is that what you crazy kids are calling it these days? :lol:


:lol: :lol: :lol: :D

[AirMoore]

To the original poster I will try to help clarify something for you since no one else mentioned it.


Peak and tune is used in CB talk for a specific reason: A RD for Escort/Bel/VR etc etc comes with the highest sensitivity possible, there is 'no limit' placed on them by any governing body (as far as how sensitive their RD's can be on the given police-radar frequencies)... not that I am aware of at least. In other words... it would not be beneficial for them for any reason (other then cost savings... which the highest end RD's aren't concerned with) to make an RD less sensitive then it 'could' be in the same price range: If doing the things you mentioned would help... they would do it, take 15 more dollars on the RD for their 'labor' and call it a day.


With CB's why you see a 'peak and tune' is because the FCC limits the output to 4 watts... if a company goes past 4 watts on this from the factory: They get VERY stiff penalties... so even though most of the radios these days that the companies make can 'put-out' 2,3,4,5x the legal limit when peaked and tuned, the companies cannot do this in fear of the penalties from big brother. Most actually come with just over 3 watts, to allow for manufacturers variance.

[o2bad455]

Thanks for all the replies so far. I think we've all either seen or heard of particular examples that are just a little bit hotter on particular frequencies than other examples of the same model (and revision). Assuming that the firmware is identical, what's most likely to make those units hotter? Minor variations or reduced mis-matches in electronic components, or differences in the horn antenna?

[jdong]

Mainly manufacturing variance that's characteristic of any mass-manufactured device -- how closely each one of its components match the advertised values on the spec sheets.

[MEM-TEK]

Identical Bel/Escort products generally perform within a 2dBm variance from what I can gather. Thats a 2dBm total variance, not +/-2dBm of variance, which is pretty amazing.

[Whistler1]

Mem-tek,

A 2 dbm variation is pretty amazing on a superheterodyne receiver thats capable of producing sesntivity figures between -110 and -120 dbm values.


Whistler1:D:D

[MetalFlame]

Knowing all too well that radar detectors are mass production, what can be done to optimize a modern detector if one has the time and patience, and is willing to track down the right tools? Since most of the operation is defined by firmware, I'll start by ignoring that and considering just the horn. Can anything be done to improve the horn's efficiency, such as smoothing and blending the top to bottom seam, for example? Polishing the inside? Camfering the lip? Or is any change more likely to hurt than help?

You can build a horn extension for your RD.Here in Europe Horn extensions are quite popular and VERY effective.Most of this horn extensions are for M4/S7 remote RDs,but it will work with any dash RD that uses M4 or S7 platform.
There's even an official Beltronics/Target horn extension available for EU market.

[languy99]

You can build a horn extension for your RD.Here in Europe Horn extensions are quite popular and VERY effective.Most of this horn extensions are for M4/S7 remote RDs,but it will work with any dash RD that uses M4 or S7 platform.
There's even an official Beltronics/Target horn extension available for EU market.


do you have a link maybe?

[languy99]

I found this if anyone is interested.....

http://portalvasco.com/blog/ficheros/filtros/enerbydiseno.jpg (http://portalvasco.com/blog/ficheros/filtros/enerbydiseno.jpg)

This is where I found it, its translated form a Spanish site I think. LINK (http://translate.google.com/translate?hl=en&sl=es&u=http://portalvasco.com/blog/%3Fp%3D598&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3Dhttp://portalvasco.com/blog/%253Fp%253D598%26hl%3Den%26rlz%3D1B3GGGL_enUS249US 249)


I also foudn this, its called a cone amplifier ( they have videos) Translated version of http://www.euroradares.com/b2c/index.php (http://translate.google.com/translate?hl=en&sl=es&u=http://www.euroradares.com/b2c/index.php&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3Dhttp://euroradares.com/b2c/index.php%253Fidaf%253D5%26hl%3Den%26rlz%3D1B3GGGL _enUS249US249)

[o2bad455]

Interesting. The horn extensions that neck down before the detector are primarily used to block the LO emissions from the RD (to avoid Spectre RDD). The Enerby version seems to make the RD equally sensitive to horizontal or vertical polarization, which is more of a problem in Europe than North America (where most guns are now circular polarized). As I understand it, the sensitivity "gain" is only versus the RD when mismatched (e.g., horizontal polarized RD to vertical polarized gun, or vise-versa). The horn extensions with neck-downs actually seem to cause a loss of roughly 4 dB sensitivity for horizontal to horizontal or vertical to vertical.

That said, I don't see why a new horn extension without a necked-down section couldn't be made to increase sensitivity simply by catching more signal. I wonder if it could simply be placed in front if the RD was positively located, or if it would need to be attached metal to metal.

[languy99]

check these out

http://euroradares.com/data/productos/cono1-f.jpg

http://euroradares.com/data/productos/cono2-f.jpg

http://euroradares.com/data/productos/cono3-f.jpg

check out these videos of that same setup running:

without the horn:

YouTube - 975R HHE - Sin cono (http://www.youtube.com/watch?v=c7k51B60s6s)

with the horn:

YouTube - 975R HHE - Con cono (http://www.youtube.com/watch?v=pz2FJllvkrw)

[o2bad455]

Sweet! My initial guess is that that level of increase must actually be due to crossed polarization, though. Note that the extension has an increased width and height, which might help with the polarization issue. I wonder if there would still be a noticeable improvement if the polarization was matched to begin with. I wish I understood antennas better.

[languy99]

yeah I have no clue about antennas, you know more than I do. who knows how much better a v1 would be with something like that. I should try to build a mackup one and test it. I wonder, can I just use cardboard and line it with aluminum foil on the inside for testing?

[o2bad455]

yeah I have no clue about antennas, you know more than I do. who knows how much better a v1 would be with something like that. I should try to build a mackup one and test it. I wonder, can I just use cardboard and line it with aluminum foil on the inside for testing?

I'd like to try with my V1 too. Aluminum foil over cardboard sounds reasonable to me, but I'm really just guessing. It seems like it would have to be electrically connected to the existing antenna, so I don't see how that slip on extension shown above could really work. But, then again, maybe a disconnected passive (versus connected active) extension could do something useful.

I'm trying to learn more, and just had a look at one of VR's older antenna patents. US Patent No. 4878061 makes me think that actually shortening the antenna a tiny bit might help Ka at the expense of X by better compensating for phase delay in Ka. Here's a quiote from that patent:
An analysis of the wavefronts in the horn antenna 100 from the launching waveguide at the back of the antenna 100 to the vanishing point or plane 108 of the ridges 106, 106A shows that the wavefronts develop smoothly from planar surfaces at the back (although with highly nonuniform amplitude cross sections typical of ridged waveguides), to distorted curved surfaces in the body of the antenna 100, and finally to a slightly distorted concave surface at the plane in which the ridges vanish. Extension of the antenna 100 beyond the plane 108 with the same flare but with no ridges, introduces a distortion of the wavefronts which reduces their concavity. At one extension length, the wavefronts become very nearly planar. This extension length is optimum for the antenna and results in the highest possible aperture efficiency and directivity. Any further extension of the length of the antenna will cause the wavefronts to become convex again resulting in increased phase errors.

[languy99]

Well I just did a test with a ghetto horn setup on a k-band door. No improvement whatsoever.

[o2bad455]

Well I just did a test with a ghetto horn setup on a k-band door. No improvement whatsoever.

If you just slipped it over the detector, you might next try adding a grounding wire from the extension (foil?) to the V1 (perhaps at one of the torx fasteners) to see if that makes any difference. Also, try to make sure that the foil makes a sharp 90 degree angle at the corners, which might be harder with the foil on the inside of the cardboard.

[MetalFlame]

languy99,that picture you first posted is a RDD filter with -18dB/cm2 gain for M4 platform,but it will not work in USA, because it's a dual-bandpass ONLY,that means it only detects 24,125GHz and 34,3GHz.

The other two pics are not RDD filters,they are horn extensions with -23dB/cm2 gain.

This is the official Beltronics/Target horn extension:
TARGET ANTENNA BOOSTER|BELTRONICS|COMERCIAL CHAMEN - los precios mas bajos en electronica Andorra - FOTO DIGITAL, VIDEOCÁMARAS, ANTIRADARES, PDA'S, CAR-AUDIO los mejores precios con 25 años de experiencia como tienda real . (http://www.comercchamen.com/tienda/index.php?page=pp_producto.php&md=0&codp=1232)