Hi Charlie,
many thanks for providing the info, which is very helpful. I wonder what’s the difference between the two copper panels you used in the first place and this one. I felt a bit confusing about the performance, one better and one inferior than the aluminum panel, I really think there would be no much difference for a pure copper disc and one laminated with copper tape? thanks,
The first ground plane I made was too small and not symmetric on the antenna - also the ground plane for the base antenna was a large steel baking tray, so not very similar. As the size of the ground plane attects the antenna tuning I think it is probably advisable to have identical ground planes to try to ensure the same signal strength on the same sats for bot base and rover unit.
The second set of grouns planes were 2 disks of approx 200mm diameter and one of 110mm ish. Again hand cut from some 1mm aluminium sheet that was lying around, so not perfectly circular or identical. These worked OK but the plane for the airborne unit was rather large and heavy.
The cds laminated with copper tape are lightweight, more or less identical, and seem to perform as well as the pair of 200mm aluminium disks I was using. As a bonus you can cut a slot from the central hole out to the edge of the antenna and get a very neatly hidden antenna wire, which might help as well.
All the above is pretty subjective, I’m afraid I haven’t had the time to compare the differences in controlled experiments or anything like that. More research is needed 
Many thanks for the thorough explanation, really much appreciated. It’s very different than what I thought previously- I was thinking the better performance was resulted from different material of ground panels for copper obviously having much better conductivity! I guess I will try with both large aluminum panel (200mm) and copper panel (100mm) by laser cut and see what the difference is Also, I would assume a thicker one (2mm) probably will yield good result since it’s less likely to deformation.
Hi Larry,
thanks for the info about the tw2405, the long duration of fix is just amazing! however, I found it was really difficult to understand the reason behind the huge gap, because I really can’t find much difference purely from the tech specs…
I felt really confusing about better alternatives of antenna, especially the tw2405 and tw3710, which one would be better in your opinion? thanks,
Ha! Brilliant!
May I just ask what kind of copper tape you used, conductive or non-conductive? Sorry if it’s a dumb question…
sure, it was some of this stuff:
Brilliant, thanks!
Leo
In general, the bigger the ceramic portion of the GNSS antenna is, the stronger the signal you will receive. The TW2405 and the TW3710 have the same size ceramic area, 50mm round or 1963mm^2.
The Reach kit antenna, a Tallysman TW4721 has a 25mm square ceramic area or 625mm^2.
When the Galileo satellites are all in place in a few years I would think that an antenna for GPS and Galileo would be the best. For now, the TW2405 GPS and Glonass antenna works for me but the Reach guys are working at getting the 14 satellite Galileo system to work with the Reach. In two years the Galileo system is likely to have all 30 satellites in orbit.
Larry
