HackRF One covers many licensed and unlicensed ham radio bands.

It processes Digital Signals to Radio waveforms allowing the integration of large-scale communication networks.

HackRF One has an injection-molded plastic enclosure and ships with a micro USB cable.

HackRF One is a test equipment for RF systems.

It has not been tested for compliance with regulations governing the transmission of radio signals.

The Siglent provided many kinds of signals I used to validate and improve PLSDR.

This sort of project is much easier and less expensive than it would have been during my prime years in electrical engineeering (decades ago, before I got into computer science).

After about five minutes of warmup time its very stable, reliable and cost under US40.00 (not counting the junk-box parts that tie it all together).

I originally intended to acquire a TCXO (Temperature Controlled Crystal Oscillator), which has the advantage of using very little power and not requiring any warm-up time, but is less accurate than an OCXO (Oven-controlled Crystal Oscillator), which forces its quartz crystal oscillator to a fixed temperature within a few minutes of activation, after which its very stable.

A normal USB connection should easily provide this amount of current.

This is a classic remedy for ground loops, and the result of the above remedial steps is a nearly complete absence of 10 MHz leakage in a room where sensitive shortwave receivers are operating.

The best comparison reference for everyday use is WWV, the U.S.

Fort Collins, Colorado and Hawaii and that broadcasts at 2.5, 5, 10, 15 and 20 MHz.

Adjusting the frequency standard against an on-air radio signal is a bit tricky, but after adjusting for equal signal levels (using the Siglents level controls), a zero-beat is easy to hear without special equipment.

Its even easier if you use an SDR like PLSDR with a spectrum display for equal signal strengths, when approaching a frequency differential of zero Hz one cannot hear the beat any more, but the spectral peak rises and falls in an unmistakable pattern that allows adjustment to substantially less than one Hz.

The frequency standard uses the Siglent front-panel USB connector for power, and its output (Figure 3, right) is connected to the 10 MHz external clock BNC connector at the back of the generator.

I drilled a hole in the top of the project box so I could adjust calibration potentiometer R1 without having to disassemble the device.

Hackrf One Schematic