[time-nuts] ground plane for cheap helix antennas?

[Alan Ambrose]

Hi, is there any benefit in adding a ground plane to these simple timing antennas? e.g. GPS-TMG-26N

http://www.antenna.com/apg_products.cgi?id_num=11740

In which case, how big? And I'm imagining immediately underneath the antenna? This ublox note suggests probably not?

http://www.u-blox.com/images/downloads/Product_Docs/GPS_Antennas_ApplicationNote%28GPS-X-08014%29.pdf

The 58503A sitting on this atm gets '4.3us/initial 24 hours' prediction although I have seen it around 2.2us. Also max ~110 'SS'.

Also is it helpful to increase the elevation mask?

TIA, Alan