A Solution For Gpsmap60/76 C(s)x Not Regaining Fix

[Kenjobi]

I recently posted a topic regarding the fact that my GPSMAP60CSx does not always regain fixes after completely losing sight of the GPS satellites. For example, after travelling through tunnels. From other posts it appears that all the SirfStar III based Garmins are affected by this bug.

 

The post can be read at:

 

http://forums.Groundspeak.com/GC/index.php?showtopic=125226

 

I'm pleased to say that I've found a 'solution' for this and it simply involves disabling WAAS/EGNOS on the system setup screen. After doing this, I cannot get the problem to occur.

 

If you want to test this for yourselves, you could do the same thing that I did which was to enable WAAS/EGNOS, select the satellite screen and get a fix. The fix does not need to include a WAAS/EGNOS satellite (in fact, I was unable to get a WAAS/EGNOS fix during my tests). Next, cover the unit completely with aluminium foil, thereby totally blocking the GPS signals. After about 30 seconds, remove the aluminium foil. The unit should be displaying the Lost Satellite Signal message. 4 out of 5 times on my unit, the fix does not return. Instead, the satellites that were included in the previous fix briefly appear then disappear. Sometimes this behaviour repeats itself every 5 seconds or so, other times, they just disappear from the screen and never return. The only solution at this point is to reboot or disable/enable the GPS receiver with menu options.

 

Repeating the test with WAAS/EGNOS disabled I could never get the problem to occur. I tried about 20 times.

 

My conclusion is that the problem lies somewhere within the Sirfstar III chipset/firmware which may explain why Garmin have not been very forthcoming with information regarding this problem. I imagine that discussions are taking place between the two companies to find a resolution.

 

It would be interesting to know if anyone trying the above can not get the problem to occur. This could indicate that there are different hardware versions out there.

 

I hope the above is helpful to other owners of the x model Garmins that have experienced this problem. It was really causing me some difficulties and the device is so sensitive and accurate without WAAS/EGNOS that I don't really need it for the most part.

Edited March 4, 2006 by Kenjobi

[+GOT GPS?]

Thanks for the info.

 

Seems like there is a waas bug with the SiRF chips, and they need to update the SiRF firmware in the receiver chipset.