I have also learned about self cal the hard way. My older VW's battery was very weak and as a result would throw self cals on perfectly good detectors.
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I have also learned about self cal the hard way. My older VW's battery was very weak and as a result would throw self cals on perfectly good detectors.
I was hoping that this would work. If you don't get any self cal messages after a week or two of use, then you might want to dip the tip of each screw, each one removed one at a time, in contact cement and then reinstall each screw. This should permanently resolve the self cal problems since the screws won't be able to easily work loose in the future. Unfortunately contact cement dries much more quickly than ThreeBond, so you will likely have to create several puddles of contact cement while you proceed to dip each screw in the contact cement. You can use some isopropyl alcohol to slow the contact cement's drying process though!Originally Posted by Smith1000
Not one self calibration message today all of the way to work and back. Does the loose connection cause the self calibration? I presumed the detector would automatically self calibrate following a certain number of start-ups as part of its regular processing. My thought was, if the self calibration failed, it would again try to self calibrate another 1 or 2 restarts.
I am curious about the self calibration process. Is it an internal calibration or does the detector communicate externally (doubtful)? From what I recall, when I first started receiving the self calibration message, it would complete the calibration and resume normal operation. At some point later on, it would fail and the service required message would result. I would restart the detector and it may or may not work properly. Very soon, it would again get the service required message.
Would loc-tite work on those screws? Thanks.
My theory is that the slightly loose screws cause a flaky ground connection for the horn, and that this somehow interferes with the self calibration process.
Belscort radar detector models self calibrate upon every power-up and then periodically thereafter while powered on in order to correct for temperature induced frequency drift. The self calibration process is an internal one which basically involves a process of precisely adjusting the voltage to the local oscillators to make the local oscillators produce the correct frequencies relative to a single on-board crystal reference frequency. The circuitry for the on-board crystal is temperature compensated.
Anyway, it sounds like your self calibration and service required issues are resolved. Use your RD for several days more and if all is good, then open it back up again and secure the screws with contact cement.
I would NOT use loc-tite on the screws! The screws are tiny and loc-tite is extremely strong stuff! You probably will never be able to get the screws out again without completely stripping the heads. Contact cement, once cured for a day or two, has more than enough holding power yet will allow the screws to be removed if need be for servicing in the future. Just get a small amount of contact cement on the bottom third of each screw. That will be more than enough to prevent the screws from working loose in the future. You could dab some contact cement atop each screw head and onto the surrounding circuit board to secure each screw, but that would look really tacky and could pull off the silicone overcoat on the circuit board. Again, a bit of contact cement on the bottom part of each screw would be the best method and will do the needed job of preventing these screws from working loose.
How does that work?
Maybe I should have said , "The circuitry for the on-board crystal is very stable with regards to ambient temperature."How does that work?
Heck, I am not really sure if Belscort is using additional circuitry in conjunction with the crystal to assure a very accurate reference frequency regardless of ambient temperature. It may be that the reference frequency from the crystal is stable enough throughout the specified operating temperature range of their radar detectors that an additional temperature compensation circuit is not needed. This really is a question for Jimbonzzz, the Professor, since he has delved into the operation of radar detectors in general considerably more deeply than I have.
A crystal oscillator by nature is very stable over temperature changes. In the X50, the 1st LO is calibrated by examining mixer products which result from mixing the first LO with the 2nd LO. Since the 2nd LO is crystal referenced, the 1st LO can be accurately calibrated.
Interesting, thanks for your inputs. How do police dash units maintain accuracy after baking in the sun? Similiar techniques?
Hi Smith1000,
How is your X50 doing now after a few days? I am dying to know whether or not it is still giving you self calibration error messages!
--Michael
Michael,
It's doing great. Not one self-calibration failure since tightening the screws and resetting. It starts up normally and has been remarkably quiet all week. It only alerted a few times this week, KA and K. The highway patrol around here uses KA and the county is K. There has been a lot of rain here this past week which translates into fewer to none running radar.
I believe it is working fine now, similar to its behavior when new. It is in highway mode and is detecing about a mile. The county will run his K constantly, so it is easy to tell as the signal becomes stronger. Many thanks!
If and when the problem occurs again, I will put some contact cement on the screws.
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