On 1/26/2016 11:52 AM, walter shawlee 2 wrote:
I have been working on a compact portable 10Mhz bench standard using both an FE FE5680A Rb oscillator and an Oscilloquartz ovenized
It is important for a 10 MHz source to launch a pure sine wave and also to have an accurate 50 ohm impedance at 10 MHz and its harmonics. This is because a sine wave is the only waveform having the property that it is immune from distortion due to reflections from poorly matched loads. IE, sine wave with multipath resolves again to a sine wave. It is important to have a broadband 50 ohm output impedance to absorb reflections from loads, especially load-generated harmonics. You didn't ask, but you also want a lot of reverse isolation to avoid pulling the OCXO. All of these were addressed in the design of the output section of the 5071A cesium standard. It was really quite non-trivial. Specifically, the harmonics are down over 80 dB. Rick Karlquist N6RK _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.