This HP Z3801A is located in Waushara County, Wisconsin USA. It is powered by a Gordon Kapes Model 733 Telecom 48 Volt UPS. GPS timing signals are received by a Model 58532A HP GPS LNA amplified timing antenna. The HP Z3801A's frequency accuracy is better then 1 X 10 -9 (better then 1 hz in 10 GHz) and has been measured to 1 X 10 -11 (you do the math). It is comparable to or better than a Rubidium frequency standard ! The standards were originally utilized in CDMA sites for synchronization of the various cell site towers and transmitters as well as in E911 dispatch sites. They make a great laboratory standard and their frequency and timing accuracy can be traced to NIST. The standard has a handy 10 MHz BNC output on the rear, several other 10 MHz oututs as well as a 1 PPS timing output. The best web site available with understandable information for the amateur radio operator and others interested in the HP Z3801A is Bill Jones's, K8CU Real Ham Radio Site. Bill authored an article published in QEX regarding the utilization of the Z3801A for weak signal VHF work... an idea which has also caught on with owners of high end HF receivers and transceivers as well as test equipment.
To learn more about the software which generates this data, and the HP Z3801 receivers, please visit K8CU at:
www.realhamradio.com
Power-on time
Days Hrs Mins Secs
Days Hrs Mins Secs
HEWLETT-PACKARD,Z3801A,3542A01175,3543-A. Life count: 61019
SYNCHRONIZATION ............................................. [ Outputs Valid ]
SmartClock Mode ___________________________ Reference Outputs _______________
>> Locked to GPS TFOM 3 FFOM 0
Recovery 1PPS TI -9.8 ns relative to GPS
Holdover HOLD THR 1.000 us
Power-up Holdover Uncertainty ____________
Predict 300 ns/initial 24 hrs
ACQUISITION ............................................ [ GPS 1PPS CLK Valid ]
Satellite Status __________________________ Time ____________________________
Tracking: 5 Not Tracking: 3 LOCAL 17:17:02 21 Jun 2025
PRN El Az SS PRN El Az 1PPS CLK Synchronized to UTC
10 61 314 189 8 12 300 ANT DLY 0 ns
18 33 165 85 15 16 63 Position ________________________
23 64 80 77 *27 Acq . MODE Hold
24 46 73 107
32 43 244 135 LAT N 44:07:25.542
LON W 89:04:09.085
ELEV MASK 10 deg *attempting to track HGT +267.35 m (MSL)
HEALTH MONITOR ......................................................... [ OK ]
Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK