Radar information Pages

MPH industries / K 15 - 2, Handheld K band radar unit.

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K band radar 24.150 Ghz

This device works well with large reflective surfaces such as cars & trucks.

It has "read through lock" where the operator squeezes the trigger and a speed

captured is then held in the lower bar while the operator can continue to read speeds.


How it works

Example start up for the testing shown here:

Plug unit in to cigarette lighter or regulated power supply 12 volts.

Power up (left switch up) unit in Standby mode (2nd left switch down)

Point unit out window (to minimize strong return reflections) flip transmitter to "run".

( To check the calibration of the unit we strike* a K band tuning

fork which produces a 65 MPH reading in front of the antenna. )

Strike* tuning fork and obtain a 65 MPH reading....

This should be done each shift / day if not at each reading.

Each state has rules about the length of time between certifications.  6 mo./1 yr

Right switch (mode) checks all LED segments/digits & displays sample reading.

 

Unit is ready for readings / clocking / speed monitoring.

Point head-on (parallel) to oncoming traffic or in direction of car travel.

Here are two reflection readings from driving down the interstate

 

These show "Our" speed from the reflection of the signal off trees and signs.

In order for the operator to "lock" in that reading, they have to press the trigger

to display the reading in the lower window

Here the top reading (by read through lock) is a current reflection or vehicle speed.

Below is the "locked" in speed 74, previous to the 72 in the top reading.


Audio:

There is an audio "doppler" sound from the units speaker (right dial) on the unit.

It puts out a tone which changes when a car or reflection is returned to the

antenna from the K band signal sent out.

Operator needs to listen to this (annoying) while clocking to verify a valid reading / target.


Field Report.

This gun has a somewhat limited range and may be due to the age of the unit.

Its handle is ergonomically comfortable.  The K 15 - 2 is a longer version of the K 15.

All the pictures below are of the K 15 - 2

The operation of this unit is a two hand operation if being handheld.

Therefore, it took quite a calculated effort to flip the transmit switch

(white box below) to obtain reading independent of squeezing the trigger.

Don't be fooled by ease of operation with this unit unless you left it "on",

transmitting all the time, which is bad for the electronics inside (mixer diode)

Range was approximated at 1/8 mile or ~1200 feet. Dependant on Target.


Surprisingly, this unit was very susceptible to interference from the defroster fan.

Here is a 1999 Audi A4

It was also similar in a 1999 Audi A6 Avant and a 1993 Ford F150 truck

The above photo is at highway speeds and the fan reflection

 is stronger than the trees alongside the road.

Notice the left red light on "run"  Fan speeds gave readings from 12 - ~36 MPH

Here, I "locked in" (below) the vehicle speed during a strong reflection.

Still the fan interference is obvious here. 

No traffic ahead, so this 13 is NOT a closing rate to traffic ahead.

Here are two reflection readings from driving down the interstate.

 

These show "Our" speed.  Here the defroster has been turned off.

This gun seemed less sensitive to reflections in comparison to a CMI Speedgun X - band.

There is a range dial (left) on the unit.  It was turned right to Max.


During Internal unit calibration (ICT reading of 32) units RF light

 

would sometimes flash signaling Radio Frequency interference.


Below are ghost readings when audio is left on a while in 'Standby" mode.

 

  

All these are related to the Doppler Audio Volume Dial/Knob turned up and the ICT reading.


Cross Readings or Interference:

High power radios, transmitters, power lines are all documented sources of interference.

Both the X band 10.525 Ghz and the K band 24.150 Ghz frequencies are so close,

I always suspected interference or the ability to receive another's signal as a speed reading.

So I tested them against each other at about 120 feet.  This MPH K 15-2 would only ghost a reading as described above.

It also didn't register a speed when a X band gun was aimed at it from 1 - 100 feet.

While the  MPH K 15-2 gun wouldn't register a speed from the CMI Speedgun,

the Speedgun would register 29,30,31 or 32 MPH when picking up the K band transmission.

 

Like listed above this gun would pick up fan interference in 1999 Audis often.

It was such a strong signal, it would take a large reflection to obtain a vehicle reading.


Tuning Forks.

I cross referenced these five forks:

80 MPH X - gives ~34/5 MPH on the K band gun

65 MPH X - gives ~28 MPH on the K band gun

60 MPH X - gives ~26 MPH on the K band gun

30 MPH X - give ~13/14 MPH on the K band gun

65 MPH K - gives ~149 MPH on the X band gun.

This table means each X and K frequency band will overlap into the other

in determining the speed of a target.  Direction of the target (towards or away from) will

determine if there is a frequency overlap or not.


Glossary & Reference:

Strike * :  Some manufacturers claim to strike the metallic tuning fork on a non-metallic surface to produce an accurate tone.

Striking a tuning fork on a metal surface can dent the fork, damage it, or create false

overtones which will affect readings obtained by the unit.

These units have 6 digits in their serial number.  This unit was purchased on Ebay.

Red Lights:

 Run:  Transmitting Radar K band signal.

Standby (Stby):  Unit powered on but not transmitting radar.

RF:  Radio Frequency Interference, lights up when other signals are around

LV:  Low Voltage.  Unit may Malfunction or not work correctly.

Sample rate:  is how often a new reading is taken and displayed.

K band radar is 24.150 Ghz frequency.

Operators Manual


K 15 Handheld Gun reference: