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Old 05-14-2008, 11:28 AM   #1
skip_168
Registered User
 
Join Date: Jul 2007
Location: florida
Posts: 111
Haha.. RF engineer 1, Porsche dealer 0

I love being an engineer.. check this out:

I have a 2000 boxster, and of course the remotes quit working...

So, I bring the keys into the Lab where I work, mostly RF(radio frequency) stuff, and check them out...

I used a Rhode & Scwartz Real Time Spectrum Analyzer,($175,000 piece of test equipment), and characterize the transmitter in the key. The keys transmit a digital code on an individual carrier frequency.. pretty weak though, I got almost 40 db above the noise floor 1 foot away, and 15-20 db three feet away.. basically what this means is that our remotes' range SUCKS! pretty week for a transmitter.. ya gotta be almost to the vehicle before the signal will get through doors, glass, seats, bla bla bla... But basically, my keys work fine.

So I call the dealer and it goes like this:

Porsche dealer: service, can I help you?

Skip: Yeah, I have a 2000 boxster and my remotes don't open the doors any more..

Porsche: does the red light in the key work?

skip: yep, and they have new batteries...

Porsche: well, you need new keys, and reprograming, Parts & labor for 2 keys and programming, $450

Skip: Are you sure? what if the keys work fine?

Porsche: no, the keys don't work, they stop transmitting... its always the keys..

skip (in my best engineering voice):
well, I'm a RF engineer and I used a Rhode & Scwartz Real Time Spectrum Analyzer and characterize the transmitter in the key. The keys transmit a digital code, which I demodulated and have written down, on an individual carrier frequency. I got almost 40 db above the noise floor 1 foot away, and 15-20 db three feet away,so my keys are transmitting....

Porsche dealer: uh... oh..... mmmm.. ok, well then your car needs to be reprogramed for the keys...

skip: how much is that?

Porsche: 60 bux...

skip: Ok, I'll bring the car down friday & we can try that... thanx...

Porsche: uh... ok...(click)



Now as fun as this was, I might need new keys, but I need to do more research, on the forum...

They did say I needed a bar code for the keys, but all that has is the code the keys transmit, which I have.. I can tell you one thing, I wont spend $187ea. for keys..

so I'm off! as any engineer, I love a challenge!
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