[time-nuts] Advice on 10 MHz isolation/distribution (Clay)
life_speed at yahoo.com
Sat Feb 20 20:01:04 UTC 2010
From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] Advice on 10 MHz isolation/distribution
The calculation is useful to help eliminate amplifiers that will not
meet the phase noise floor specs.
The amplifiers that remain will then need to be tested/measured for
their actual phase noise.
I have been thinking about how to make the measurement. I don't normally measure OCXO phase noise. I buy them to spec and lock my synthesizer to them, measuring phase noise at microwave frequencies using an older Agilent E5500 system with an 8254 (?) signal generator reference, which is an older version of their 8257.
I was thinking I could split an OCXO signal, run one path thru the amp, and then mix them together and put the IF output into the E5500. I think I would need a phase shifter to ensure the signals are in quadrature at the mixer. I guess if I had two OCXOs I could let the E5500 control the EFC port on one, it would then use it's internal PLL to lock the 'reference' OCXO to the 'DUT' OCXO/amp.
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