Cannot get a fix or a find any satellites with GNSS Multi-Band L1/L2 Surveying Antenna - TNC

GPS/GNSS Development Boards
1

Hi,

I’ve paired https://www.sparkfun.com/products/17751 with https://www.sparkfun.com/products/22693 - and not able to find any satellites.

I’ve tried another antenna https://www.sparkfun.com/products/15192 - and everything works as expected.

I’m not sure if I’m dealing with defective product, or I’m doing something wildly wrong. Would I need to configure anything differently for the TNC antenna?

I’ve used this 10m cable https://www.sparkfun.com/products/21740 - using such a long cable would I need to inject power additionally? If so, how do I do that?

Thanks!

2

10m is NOT a long cable

Make sure your SMA to uFL is working that the uFL is suitably mated to the board.

You should be able to measure a DC voltage between the center pin and the ground.

Probably 3 to 3.3V

Check also at the end of the TNC

Check the antenna spec’s for expected / workable voltage ranges.

To inject power you’d look at a Bias-T or powered GPS/GNSS splitter

3

My apologies, I provided the wrong product link https://www.sparkfun.com/products/22660

I have the F9R with SMA connector.

I’ve checked voltage at the end of the TNC and it’s within the 3 - 3.3 range, and this should work with this antenna. It was also featured in one of the tutorials.

Thanks!

4

If you’re measuring ~3.3V at the end of your SMA+TNC cable I suspect it’s a faulty antenna. The TOP106 antennas are good but not without its failures. I recommend starting a issue with Tech Support for a replacement: https://www.sparkfun.com/returns

5

Could check also DC voltage at receiver with the antenna attached. If significant load presented by antenna the voltage will drop.

Powering the antenna via a bench supply, say 3.3V with a 75mA current limit, you could see the draw from the antenna. Shield ground, center core DC

Spec implies around 45mA at 3.0V, but would surprise me if it’s that high