[time-nuts] Getting my Rockwell D200 GPS to work

[Hal Murray]

dlewis6767 at austin.rr.com said:
> The antenna is currently on a shelf above my workbench, ....there is a
> ceiling and an upstairs above it. Then the roof.  

> Is it very critical to be outside in order to 'see' the sky?  

> I did take it out once and set the antenna on my car roof, ....but still no
> satellites. 

How long did you leave it on your car?

There are two problems in this area.

One is being able to hear the satellites.  There may not be enough signal at 
your workbench.  It depends upon how sensitive your receiver is.  Most of my 
newer GPS receivers work in my house.  Older ones work less well.

The other problem is what frequency to listen to.  The satellites broadcast 
the orbit parameters.  That lets a receiver calculate the frequency to listen 
on.  (The Doppler correction is important.)  In order to do that, you have to 
know the time.  That's why there is a pin for the backup power to the clock.  
Without knowing the time, the receiver has to do a brute force search which 
takes a while.

I would put it in the best location you can easily get to and wait a while.  
It may take 15 minutes or longer.  I wouldn't get upset if it takes a half 
hour.

Once you get it working outside, you can take it inside and see if it still 
works.

If you unplug it without the backup battery you will have to start over again.

You can also just let it run overnight and see if that works.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.