GT-730F doesn't work
I have had a GPS GT-730F, built by Canmore, also known as Gisteq GR110, I believe. It works great, plug it in anywhere in the house and it finds satellites.

I bought two more and see two things. First the green LED is much dimmer, not that it matters in itself, actually it's better. Second, no data even next to a window, not a single satellite.

I have seen reference to drivers but I assume that is the USB to serial and anyway, the original unit works fine although it shows a prolific serial drive on COM3 whereas the two new ones are USB serial port COM4.

Anyone any ideas?

I tried the firmware update but that seems unlikely since my original unit is older and the update process would not work.
Ken in Regina
How long did you have them plugged in? All new units need to go through a "cold start" routine before acquiring their first fix. If their location of manufacture is a very long distance from your location or/and if they have been sitting in the box for a long time, this cold start period could be quite long. I have had cold starts from brand new devices manufactured in Asia take as long as 20 minutes or more to get their first fix.

In one case the new device simply refused to get a first fix indoors. I had to take it outside and put it on a table in the back yard for 20 minutes before it would lock on.

Something else to be aware of, although it may not apply in this specific instance ... putting a receiver in front of a window may not do anything useful. Most modern house windows are no longer just glass. The more energy efficient windows that have been installed for the past 20 or 30 years have a film in them to help block infrared and ultraviolet. Many of the formulations used also block radio and TV and GPS signals quite effectively.

The picture windows in my living room were installed about 25 years ago. They were about mid-class for energy efficiency at the time. If I want good GPS signals inside the house I get better performance in the middle of the living room so the signals only need to come through wood and drywall. Actually, my best reception in the house is at the kitchen table which is nearly smack in the middle of the house.


Thanks for the thoughts and the benefit of your experience. They sat in computers overnight although indoors. My older unit, with the previous chipset gets a signal in the house without a problem but perhaps a cold start would take even longer in the house.

I have one of those units that can recharge a phone, I'll attach one of the GPS modules to it and put it outside overnight.

Once one of the units has an opportunity to establish a cold start outside, you might want to plug it into the same USB port as the working one (not at the same time, of course). Then you could test it under the same conditions on the same Com port as the original.

Generally the Prolific driver will install and establish a different Com port output for each of the USB ports you connect the device to.

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