Ashtech Z12 GPS Receiver


&

Z Reference

&

Ranger


© Brooke Clarke 2009 - 2022
Z12
   Photos
   Background
   Getting Started
   Factory Defaults
L1/L2 Antenna
Connectors
   Z12
   Z Ref
  Post Processing
Z Reference
   Photos
   Disassembly
   Operation
Ranger
  Photos
Related
Links

Z12

Photos

PAstech Z12 Reference Station Front
Astech Z12 Reference Station Back
Ashtech Z-12-R Reference Station
                GPS receiver top removed
The top is held on by three screws on the left panel and three on the right panel.
Ashtech Z-12R Searching for SVs
The GMT shown: 21:49:14 is correct.
SVs 25, 26, 30, 23, 13 & 16 are carrier locked but not phase locked.
Data Port 12mm ID Fischer Connectors
Some Z12R receivers have DB-9 connectors and some have Fischer Push-Pull connectors.
These are NOT 7 pin Fischer connectors like on the small box Z12.
Ashtech
                Z12R Data Port Connectors
12 VDC Input 9 mm ID Fischer 3 pin Connector
Ashtech
                Z12R 12 VDC Input Connector

Background

Ashtech developed a better way to use the encrypted L2 signal.  The prior art was to square L2 and the Ashtech method has a better signal to noise ratio making it superior.  Also this is the receiver you want for carrier phase timing, which as of 2009 is still an experimental development.  So I've wanted one for some time.

Getting Started

Antenna Drive Voltage

The output voltage is 9.7 VDC positive on the center conductor of the Type-N male connector.  This will smoke a 5 Volt antenna like my roof top unit.
Some options:
The Trimble 4000ST L1 Geodetic, Model 14177.00 antenna runs on 10 Volts, but is an L1  only antenna.

Front Panel Keys

Pressing any one key or pressing the Red C or Red e key and any other key has no effect.  i.e. none of the key presses does anything.  This may be a fault or just some arcane way they figured out to prevent the unknowledgeable from doing harm.

Factory Defaults

Hold down the ^ (up arrow) while powering up.  Enter YES (the number 8 key) when asked if this is what you want to do.
It now ends up searching for SVs.

Setting External Ref Freq

When the EXT FREQ is set to 0.0 the internal frequency standard is used, i.e. it's not a requirement to use an external standard.
Press 4, then e, then use arrow keys to highlight EXT FREQ, press e, set to 10 MHz, then press 3, Wait for screen to change to Locked, then press e.
If the external reference GPSDO is not locked then the Z12 does not acquire satellites.  Something happened to the Thunderbolt when there was a power glitch.

L1/L2 Antenna

AeroAntenna Technology AT2775-42 with the Choke Ring comprises the  AT2775-42+CR which has known phase centers for L1 and L2.
Antenna is L1 and L2 runs from 5 to 18 VDC.
AeroAntenna
                Technology AT2775-42 with the Choke Ring
AeroAntenna
                Technology AT2775-42 with the Choke Ring
For info about the pole and bi-pod see the DAGR page

NGS NOAA - GPS Antenna Calibration
ANTENNA ID        DESCRIPTION                  DATA SOURCE (# OF TESTS) YR/MO/DY

[north] [ east] [ up ] | L1 Offset (mm)
[90] [85] [80] [75] [70] [65] [60] [55] [50] [45] | L1 Phase at
[40] [35] [30] [25] [20] [15] [10] [ 5] [ 0] | Elevation (mm)
[north] [ east] [ up ] | L2 Offset (mm)
[90] [85] [80] [75] [70] [65] [60] [55] [50] [45] | L2 Phase at
[40] [35] [30] [25] [20] [15] [10] [ 5] [ 0] | Elevation (mm)
AERAT2775_42+CR      Marine III +CR adaptor                   NGS (  4) 05/05/31
-0.1 -2.6 65.7
0.0 1.2 2.0 2.6 3.0 3.2 3.2 3.1 3.0 2.8
2.7 2.5 2.5 2.4 2.4 2.5 2.6 0.0 0.0
-0.1 -0.4 93.6
0.0 -0.3 -0.4 -0.5 -0.4 -0.4 -0.3 -0.3 -0.3 -0.4
-0.4 -0.5 -0.6 -0.6 -0.6 -0.5 -0.2 0.0 0.0\

Results

On Page 0 in the linse for STAT, PL1 & PL2 the letters LK (Lock) appear under all the SVs that are visible. 

Connectors

Z12

They are fischer A086, 104 series.   (Plastic)  (Metal)
# of
contacts
Contact
pin
Config
Interface
Metal
Plug
Contact
Block
Top
Shell
Bottom
Sheell
Ferrule
3
A040
U1 504-A
S 103 A040+



11
A056
U1 504-A S 104 A056+



16
A086
U1 504-A S 104 A086+ E21 504-A086-J (solder)
E21 504-A086-K (crimp)
U31 504-A03 (blu)
U31 504-A04 (vio)
U31 504-A09 (trq)
U32 504-A03 (blu)
U32 504-A04 (vio)
U32 504-A09 (trq)
U33 504/5.0

        Z Reference

Post Processing

By recording precision data on the actual orbits of the GPS satellites and using that data along with time stamped data from a precision GPS receiver the data can be reduced to determine the precise location of the GPS antenna used.  This is a version of Differential GPS (Wiki).

0. Find mating connectors.
1. Record receiver data and convert to RINEX format.
TEQC — The Toolkit for GPS/GLONASS/Galileo/SBAS Data -

2. Submit RINEX file to Online Positioning User Service - which uses three CORS sites to reduce data.
--------------------
http://www.ngs.noaa.gov/OPUS/
IGS Station Quincy, California (Wiki)- 39°56′11″N 120°56′53″W

http://www.movable-type.co.uk/scripts/latlong.html

Enter the co-ordinates into the text boxes to try out the calculations. A variety of formats are accepted, principally:

  • deg-min-sec suffixed with N/S/E/W (e.g. 40°44′55″N, 73 59 11W), or
  • signed decimal degrees without compass direction, where negative indicates west/south (e.g. 40.7486, -73.9864):
Point 1: ,
Point 2: ,
Distance: 207.3 km
Initial bearing: 247°06′23″
Final bearing: 245°41′41″
Midpoint: 39°34′06″N, 122°03′43″W

And you can see it on a map (aren’t those Google guys wonderful!)

Z Reference

This GPS receiver includes an input for an external frequency reference, unlike the Z12 above.  This might better lend it to precision GPS work.

Photos


ZR Fig 1
Ashtech Z
                  Referrence GPS receiver
ZR Fig 2
Ashtech Z
                  Referrence GPS receiver
ZR Fig 3
Ashtech Z Referrence GPS receiver
ZR Fig 4 Inside
Compact Flash drive: SanDisk 90 MB
Battery: TL-5/86   3.6V (unknown condition)
Ashtech Z
                  Referrence GPS receiver

Disassembly

Remove front panel (+) screws and hinge down the panel.
NOTE:  Be very gentle pulling off the connectors after noting which goes where (mine were marked I, II,X and O, but the X socket came off the PCB and needs to be soldered back down.
O: switch
X: circle light
II: Satellite light
I: Drive light
Remove the three hex head screws using a 3/32" ball end hex wrench.
Remove the back panel (+) screws and slide the PCB and rear panel assembly out the back.

Operation

Ranger

This GPS receiver has the look and feel of the rack mount Z12, but much smaller.  If you compare this receiver to the one at the top of the page, it's the same size as the main part and has an identical front panel.  But the rear panel uses different connectors than the above receiver and different from the field version Z12 shown in the Z12.pdf manual.

8 Feb 2017 - added

Photos

Fig 1 Carry BagAshtech
                  Z12 Ranger GPS Reveiver
Fig 2 Front panel with Z12 look and feel
Ashtech
                  Z12 Ranger GPS Reveiver
Fig 3 Field connectors different than rack unit.
Power In dust cap: Amphenol 97-60-10
Power Cable connector:  3106A10SL-3S
Power Voltage: TBD
Ashtech
                  Z12 Ranger GPS Reveiver



Power Connectors

To make power cable use: 3106A10SL-3S.
The two power connectors both have pin-B as chassis ground, but pins A and C are not interconnected on them.
This implies that the idea is to have two independent power sources so that one can be changed while the other provides continuous power.  For that to work there needs to be diode isolation so the dead battery does not drain the good battery.  The ZY-12 supplemental manual has the pin out table.

Pin
Function
A
+10 to 32 VDC
B
Chassis Gnd
C
-10 to 32 VDC

Guess input as 9 to 32 VDC.

Operation

Modes:
Z mode: A - receiver reverts to Z mode when A/S is detected, Y - always in Z mode, N - never Z mode.
Ranger mode: 0 - geodetic mode: stores phase data in B-files for post processing, 1- Stores phase data in B-files for post processing in code phase only, 2 - stores smoothed positions in C-files only, used for real time differential corrections (no post processing).

This receiver can be used to receive Y code if it is keyed.  The manual describes how to do this with a KYK-13 and unspecified "interface box".

Screens:

Screen

0
Sky Search
1
Orbits
2
Navigation
3
Tracking
4
Mode
5
Differential
6
Waypoint
7
Satellite Selection
8
System Control
9
Site & Session Control
10
All-in-View
11
Visibility
12
Bar Code Control


Related

Ashtech GPS receivers
4GPS 4 Way power splitter for GPS
CSI LGBX Pro DGPS Receiver
GPSpat GPS & Satellite Navigation Patents
HNV600 Rockwell Trooper GPS HNV-600 & HNV-960
HP Z3805A Time & Frequency GPS Receiver
Jackson Labs - LTE-Lite GPSDO Evaluation Kit
KS-24361 (Lucent ) HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO System
Magellan GPS Commander
Magnavox MX7221 GPS Receiver
Motorola GPS Receivers
MX4102 MX 4102 Transit Satellite Navigator & MX 4200 Differential GPS receiver
Northern Telecon GPS Satellite Simulator STR2760 -
PLGR PLGR GPS Family
PLGR-II Rockwell HNV-2000 PLGR II SPGR GPS Receiver
PSN-6 R-1897/PSN-6 Loran Receiver
PSN-8 PSN-8 GPS receiver
PSN-9 GPS receiver
PSN-10 SLGR GPS receiver
PSN-11 PLGR GPS receiver
PSN-13 DAGR GPS receiver
Q5200 Quantic Q-5200/SM Timing GPS Receiver
Rockwell Trooper GPS HNV-600
Rockwell HNV-2000 PLGR II SPGR GPS Receiver
5001A Stanford Telecom 5001A Navstar Test Transmitter
ThunderBolt Trimble GPS Timing receiver
Trimpack Trimble Trimpack Family of GPS receivers
URN502 URN-502 Vehicle Mount GPS Receiver System
Z3805A Time & Frequency GPS Receiver

Links

Back to Brooke's Products for Sale, Navigation, GPS, Military Information, Home
page created 19 May 2009