Suppport Thread for the TND 500, TND 700 or future Rand McNally products.

when I was in school for land survey, we went to Trimble and downloaded software that would tell us WHEN we could expect blackouts with GNSS satellites.
http://www.trimble.com/planningsoftware.shtml

GPS is now a misnomer. GNSS has replaced it, but current marketing still holds onto GPS.
http://www.trimble.com/survey/GNSS-Surveying-Systems.aspx

Satellite links depend on location in the sky and how many satellites your receiver is seeing. The more there are and the more over head they are, the better things will be.

Granted, we worked with systems that mattered down to 0.02' over a mile. Yes, that is 2/100 of a foot for allowable error over a mile distance. The TND's we use for navigation are a lot more forgiving for us thankfully, but the technology that both rely on are similar and focus on the same basic needs. Downloads from a satellite above.

 

Just a quick FYI- GNSS is a function of the GPS constellation. The letters stand for Global Navigation Satellite System of which I believe we are into the second generation of-GNSS 2-.which is designed for the civilian market and includes WAAS which is Wide Area Agumentation System. This simply makes for tighter more reliable GPS fixes. Don't know if the TND line of PNDs have this capability or not. They probably do.

Mark

 

Mark

I found the problem and noy sure why. You said something could be interfering with the signal. Knew nothing had been added to truck in the time had the 720. But still thought its possible. Kept disconnecting things and came across the source. My dash cam. Don't understand why. It doesn't use satellites or the fm frequencies. But when remove it I get signals.

 

The satellite receiver indeed can be affected by various other electronics, including dash cams. We did some experiments with several GPS and several cams and the Garmin 465 and 560 were very much affected when they were within about 3 feet of several dash cams. The Rand and PC Miler could also be affected at times as well.

 

http://m.eyeonthehighway.com/images/720p.jpg

had it about 18 inches away. It has been there in same spot since got the GPS guess something is changed with it.

 

I had the same issue. The GPS won and the camera went bye bye. My Top Dawg camera was a Top piece of crap. With the limited dash space, got to be carefully what we are plugging in and mounting. IF can be a daunting and frustrating issue to overcome.

Mark

 

http://www.eyeonthehighway.com/?products=eye-on-the-highway

 

link still doesn't work for me. In either Chrome or IE.