Why did Bel replace the S7 antenna with the M4?

Discussion in 'Beltronics' started by warnerwh, Apr 27, 2012.

  1. warnerwh

    warnerwh Premium Member Intermediate User Premium Member

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    I keep reading about how the S7 antenna is superior in off axis sensitivity. Why would Bel go to a less sensitive antenna? Also how much difference is there between the two antennas? TIA
     
  2. CJR238

    CJR238 -CMS Article Admin- Administrator Premium Member

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    S7 = good off axis not so good reliability and more costly to make.

    M4 = Better long range, not as good off axis, better reliability, and more cost effective to make.

    I found the M4 though not as hot off axis as the S7, the decrease in bogus falses is a blessing, and the long range was more than sufficient.
     
  3. fire65

    fire65 PSL +15 Advanced User

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    Wasn't the S7 a welded antenna? That is why is was more expensive and less reliable.
     
  4. Rocky2

    Rocky2 PSL +15 Advanced User

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    The S7 platform did not like being subjected to high heat. I gave my wife my 8500x50 and she never took it down and it cooked and froze for a year and starting giving self cal errors. I got the 8500x50 repaired, but she never gave me the 9500i back and as much as she abuses that unit it still works really well.
     
    Last edited: Apr 27, 2012
  5. CJR238

    CJR238 -CMS Article Admin- Administrator Premium Member

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  6. warnerwh

    warnerwh Premium Member Intermediate User Premium Member

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    Less falses is a very worthy improvement as long as sensitivity hasn't changed. Thank you guys for the info and pics.
     
  7. Z1NONLY

    Z1NONLY PSL +15 Advanced User

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    I have an S7 I purchased in 04. It has needed service once, and it lives on my wife's windshield...in SW FL, outside. (No garage space for that car) I have not experienced better range with my 9500ix than my S7. On-axis, they are comparable. Off, axis the S7 is more sensitive than the M4.

    My guess regarding motivations for switching to the M4 platform would be false alarm reduction, and money.


    And I really wish they had worked out the ramp-up before they committed to the platform.
     
  8. Cusp

    Cusp PSL +5 Intermediate User

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    Noticed that the s7 antenna has a full horn and so is level when the RD is level. The M4 is 3/4 of a horn using the circuit board as the "missing" surface. The M3 horn is simular. This means that when the detector is level the horn will be pointed a few degrees up or down depending on if the circuit board makes the upper or lower horn surface.
     
  9. zr1

    zr1 Premium Member Advanced User Premium Member

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    Interesting.

    Now you made it so people will be up at night either:
    a) trying to figure out if the RD should be level or pointed slightly down
    b) trying to figure out if there's enough logistics to fit this into the ECCGT test

    Not to scale:
     
  10. CJR238

    CJR238 -CMS Article Admin- Administrator Premium Member

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    With the M4 design and depending on the model a slight angle up or down can assist performance ever so slightly. MEM-TEK and i discussed this quite a bit. Its also why we beveled the M4 in the 9500I did better than the M4 in the X50's since the antenna is upside down in the 9500I/IX. Basically allowing it to pick up reflections off the road/hood better.

    This picture is of a 9500I:


    I like this antenna set up because you can block the top half of the 9500I/IX with out loosing performance.

    9500I/IX can be tilted ever so slightly up with no issues. .
    Other M4's can be tilted ever so slightly down with no issues.
     
  11. PointerCone

    PointerCone M3 Kng Advanced User Premium Member

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    FWIW, my S7 RX65 often beats BOTH my V1 and Redline in off-axis alerts on K and Ka (and the start up tone on the S7 sounds like the 3 stooges) :)
     
  12. 4ringz4life

    4ringz4life PSL +5 Intermediate User

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    If the V1 has guard on then this is to be expected. Guard off i think off axis they are about equal. Redline I have no personal experience with but from the experience Xedus has had running it solo it's not too amazing in general.
     
  13. CJR238

    CJR238 -CMS Article Admin- Administrator Premium Member

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    Keep in mind there are some units within a design where some may be less or more sensitive than others. I have gotten a hot 9500IX that seemed similar in sensitivity to my V1 and 9500CI.
     
  14. SLOSHO

    SLOSHO PSL +15 Advanced User

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    My IX was only a hair less sensitive than my 3.819 on Ka.
     
  15. Xedus129

    Xedus129 Red Alert, Shields Up Advanced User

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    It varies day to day, some days its hot.. others not so much :confused:
     
  16. Nine_C1

    Nine_C1 Premium Member Advanced User Premium Member

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    This is another big advantage the S7 enjoys over the M4 that is often overlooked.........a superior Ka rampup.

    Insidercw3 debunked that theory years ago in this post. Strong reflections off the hood of the car would be out of phase with the direct beam which would actually decrease the overall gain realized by the horn.

    Is X50 more sensitive than 9500i ?

    Keep in mind that the 9500i/iX had the advantage of the microwave condensor lens where the other M4s did not.;)
     
    Last edited: Apr 28, 2012
  17. CJR238

    CJR238 -CMS Article Admin- Administrator Premium Member

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    lol, I miss MEM-TEK's very open and logical reasoning. However everyone overlooked my post/logic, reflected radar is an important factor in some encounters.

    In any case I still liked the upside down antenna, much easier to mount so it could peak out from below the tint/headliner with the top half of it obstructed.
     
  18. SLOSHO

    SLOSHO PSL +15 Advanced User

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    So I've been slightly angling my IX up.
    Should I continue or is this just a myth?
     
  19. CJR238

    CJR238 -CMS Article Admin- Administrator Premium Member

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    Its better than down.
     
  20. yellowtibby

    yellowtibby Shifter ZR4's number one fan. Intermediate User

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    I think part of it had to do with marketing reasons. The vector series used to be the top of the line model. It even had "accusweep" which was similar to RX 65 usa mode. Then they made the S7 RX 65 which had USA mode (similar to accusweep) and it was the top of the line and therefore they charged more money. The vector lost "accusweep" was the mid level performer and the bel express series was the budget level. Then they made the vector and RX65 M4 series (which essentially made them crappier) and then made a new top of the line STI Driver with the M3 horn. If they had kept the RX 65 S7 with USA mode, it would be too much of a similarity in performance to the STI driver to justify the massive increase in price. So they eliminated S7, and made M3 and M4 to add greater disparity between the vector, rx65, M3 models.