Notebook of Time and Frequency Experiments
Now that I have my GPS antennas permanently mounted on my tower, I've done a first set of measurements to determine the precise antenna location. I collected data for 48 hours on three receivers (Trimble NetRS, Ashtech ZREF, and Ashtech…
I've been looking for an antenna switching solution to use in my new ham station. I have several antennas for HF and 6M that all connect to the same amplifier in the shack, which has only a single output connector.…
I've recently become interested in dual frequency GPS receivers - the kind the are used for land surveying and geodetic research. More on that in another post. But along the way I've collected a whole bunch of antennas for these…
I'm posting this mainly because Google didn't turn up any help when I queried about using the USR-IOT serial port to ethernet converters (also known as terminal servers) with Linux. They make several low-cost devices that are really handy if…
I couldn't find a nice graph showing the timing performance of a single-frequency, sawtooth-corrected, pulse-per-second output from a GPS. So I measured a CNS-II GPS Clock and a surplus telecom HP Z3805A GPS Disciplined Oscillator (GPSDO) against a high-performance Cesium…
Each year at the Dayton Hamvention, the folks at Mini-Circuits have a bunch of odds and ends they sell very inexpensively. Over the years I've gotten tons of SMA attenuators and jumper cables, and a few amplifier blocks. I'd never…
It's well known that just about all oscillators drift, or "age", in frequency with time. In crystal oscillators, the most drift occurs when the oscillator is young, and over time the aging rate decreases. Power-cycling the oscillator results in a…
One of my Gnuradio projects is a tool that records IQ data covering 375 kHz -- which is enough to capture an entire HF ham band (except for 80/75M). A neat trick is to retransmit such a recording to allow…
My faithful HP 5065A Rubidium standard, which had been converted to a "Super" model, developed an intermittent sickness and back it went to Corby Dawson for him to perform his magic. After a realignment and fixing an intermittent connector ground,…
I've noticed that my SDR setup, an Apache Labs Anan-7000DLE transceiver used with the PowerSDR software, seems to rest the S-Meter at a quite high level when there is no signal present. This is unnerving when I try to compare…