A Good Voice SWS detector at a reasonable price?
It appears that even the radar detector manufacturers don’t know the difference between SA and SWS.
I received this email reply from my question to Cobra.
Subject: RE: Cobra 9400 SWS messages
I have another question. Do you know the bit codes for the three messages in the Cobra 9400?
The three messages you have are:
Emergency Vehicle Approaching which might be 61 Train Approaching which might be 14 Road Hazard Ahead which I can't find on the website I went to http://www.copradar.com/preview/chapt7/mess64.html
The reason I would like to know the bit code is so that I can have the ST-2000 SWS transmitter we have programmed with the correct codes that should trigger the Cobra 9400.
This was their reply:
We do not use bit codes. Your question leads me to believe that the ST-2000 sends a digital signal. Our Safety Alert system is not digital.
It works using K-band radar signals.
And this was my reply:
Thanks but you have me even more confused. My understanding is that the safety alert system should be triggered off a 10 or 14 Hz Infrared transmitter around 700 - 1000 nanometers.
The system I'm talking about is SWS and is indeed K band but uses a digitally encoded signal. The signal design is identified in US patent 5,917,430 and I've been discussing this with the Patent holder's author Gene Greneker.
The patent is available for free at
http://patft.uspto.gov/netacgi/nph-P...&RS=PN/5917430
The system uses a 32 bit message format that repeats and is about 16 milliseconds long.
From the patent documentation it states:
Bit pattern "1" in the 7th data bit position (MSB) of Field 2 represent that the previous 6 bit "word" is a fixed-text message or index number. The detector logic, upon detecting a logic level '1' in the MSB position decodes the previous 6 bits and display the fixed text message that is indicated as further herein. A value of decimal "1" is added in detector logic of a receiver to the binary count so that the message reference number is between the values of 1 and 64, inclusive. Bit pattern '0' in the 7th data bit position (MSB) of Field 3 instructs the detector logic that there is a second fixed-text message to be appended to the first fixed-text after transmission of the first-fixed message.
So my understanding of this is that a bit code is transmitted and when the Cobra detects one it uses the code to sound a coded message for that number. In the patent it says "Train approaching a crossing" is message code 4 and message code 5 is for "Emergency vehicle" while the website had different numbers and thus my confusion.
If your safety warning system isn't digital then how could it differentiate between three different signals in the same K band?
Thanks
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So does anyone know of a good Voice SWS radar detector? I’m going to try to get a Whistler in a couple of weeks but I am definitely thinking of going with Bel.