Tuesday evening I set up a Whopper antenna on a 15' rod, connected a data splitter, a Z-12 and an M-12.
The Z-12 latched on to 9 satellites in a hurry and hung on to them for most of a 1hr 25min session. The M-12 was slower catching all 9, lost one for a while regained it and finished a 1hr 20min session with 7. After shutting down the M-12 I hooked up a ProMark 2, but it refused to recognize the antenna.

When I downloaded the receivers GNSS Solutions using raw data said the M-12 was 0.22' West, 0.06' North and 0.10' higher than the Z-12. After solving the 1 second epoch files I ended up with an adjusted vector between them of 0.006'. Close enough for me.

I created 2 RINEX files and in looking at the numbers at comparable times for the same satellites, I can see no correlation between the L1, C1 & D1 values of the M-12 and the L1, C1 & D1 values of the Z-12. I guess I have to study some more. Next time I run 2 Z-12s and see iif I have an L2 antenna the PM2 likes.

Paul in PA
Modified By Lawrence Paul Lopresti on 3/6/2007 at 11:50 PM

700700c or novatel GPS600

I again tried the 700718 I used last night, a 701008-01 and a Leica AT502. The Promark 2 kept saying "No External Antenna". The 700718 and the 701008-01 have the same gain as the 700700C.

But, I found out that the PM-2 with a 4 AA battery pack will drive the AT502. So I switched my data splitter, the PM2 is seeing the AT502 through the data splitter. The Z-12 is only seeing half the satellites as the PM-2. I assume some signal loss through the DC blocker. I tried an 8 pack of AA rechargeable 1.2V batteries and the Z-12 seems a little happier. Will give it a try tonight.

Paul in PA

voltage, voltage—that’s about what I figured. Thus the 7000mah battery that sits on top of the tripod. I made a "snap" connector on one end of a cig. plug cord and applies "sustainable 12 volts” to the voltage regulator on the PM2 external power.
Cheers