Larry Dodd K4LED / AAR4IV
The charts on this page are from a surplus HP Z3801A GPS 6 channel satellite receiver with a highly stable oscillator locked to multiple (up to six at one time) rubidium NIST standard GPS satellite clocks. This receiver is located at my station. The extremely stable GPS locked 10 MHz oscillator output is used as an external frequency standard for external clocking of station frequency counters and signal generators. Highly accurate frequency control is therefore available to the station.
Transceivers like the Kenwood TS-2000 for example are easily
tuned with their front panel controls to the exact desired frequency within +-
.01 of a hertz using a GPS locked frequency counter. That takes a very careful and light touch of the XIT
control but it
can be done in less than a minute or two. Using the XIT function is the only
way to see a read out in cycles on the transceiver and only then if the rig
fine tuning function is turned on. You must use the external GPS locked frequency
counter to read the frequency down to .01 HZ. The limit is quickly
reached at that point because of the limits of stability of the rigs
oscillator and the coarseness of the XIT control. Under everyday circumstances an accuracy
of +- .1 HZ is easily obtainable and maintainable using this method.
Even this level of accuracy is well beyond current amateur radio and MARS
operational requirements.
To learn more about the software which generates this data, please visit K8CU at: www.realhamradio.com |
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HEWLETT-PACKARD,Z3801A,3542A05626,3543-A. Life count: 9132 ------------------------------- Receiver Status ------------------------------- SYNCHRONIZATION ............................................. [ Outputs Valid ] SmartClock Mode ___________________________ Reference Outputs _______________ >> Locked to GPS TFOM 3 FFOM 0 Recovery 1PPS TI -4.1 ns relative to GPS Holdover HOLD THR 1.000 us Power-up Holdover Uncertainty ____________ Predict 3.1 us/initial 24 hrs ACQUISITION ............................................ [ GPS 1PPS CLK Valid ] Satellite Status __________________________ Time _____ +1 leap second pending Tracking: 4 Not Tracking: 4 LOCAL 18:13:01 31 Aug 2005 PRN El Az SS PRN El Az 1PPS CLK Synchronized to UTC 8 24 313 62 * 3 40 48 ANT DLY 0 ns 19 70 77 31 11 19 158 Position ________________________ 23 29 187 45 *13 Acq . MODE Hold 27 56 323 58 28 13 267 LAT N 33:47:00.632 LON W 84:06:17.662 ELEV MASK 10 deg *attempting to track HGT +292.55 m (MSL) HEALTH MONITOR ......................................................... [ OK ] Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK |