Jim, You may not have to have an amplified antenna but it will work best by providing stronger signals thus allowing more SV to be tracked at any given time. This would be especially true during heavy rain periods. The primary difference between a timing antenna and anything otherwise is a design that limits reception path length differences at all elevations and azimuths. The physical appearance of a timing antenna is usually a bullet shape or small dome compared to a big square. The precise point in the antenna that provides the highest SNR to all of the currently received SVs at any elevation and azimuth is where the timing phase differences are determined. Any difference in this being a single precise point vs. multiple points that move around within the antenna’s gain pattern would define the antenna’s phase error. Don J. True-Cal Services ----- Original Message ---- From: Jim Miller <jim@jtmiller.com> To: time-nuts <time-nuts@febo.com> Sent: Thursday, June 14, 2007 11:11:43 AM Subject: [time-nuts] Antenna recommendation for Timing Amateur I'm planning on getting a M12M and would like a recommendation for an antenna for timing purposes. I'm just an amateur looking to discipline an oscillator. No scientific uses planned. My antenna coax is likely to be 30ft or more so I suspect I'll need an amplified antenna. The M12M outputs 3v so the "timing" antennas offered by Synergy don't directly apply. What is the real difference between a "timing" antenna and one meant for mobile use? Synergy offers several amplified mobile antennas that would work with 3v. tia jim ab3cv _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts