[time-nuts] Advice on 10 MHz isolation/distribution (Clay)

[life speed]

Message: 6
Date: Fri, 19 Feb 2010 15:17:44 -0000
From: "Garry Thorp" <GThorp at pascall.co.uk>
Subject: Re: [time-nuts] Advice on 10 MHz isolation/distribution

Hello Clay,

Joining in this discussion at a rather late stage  -  have you
considered using 74AC series gates as buffers? They provide reasonable
isolation and have surprisingly low phase noise.

<snip>

Hi Gary,

That's funny!  I have already done everything you describe, and shipped synthesizers with such circuits in them.  I like Fairchild UHS inverters for the logic gates.  And yes, I've done the low-noise regulators constructed from voltage references, heavy filtering, and an opamp driving a BJT pass transistor (I like the NZT560A/660A).

I will mention that for some applications, the Burr-Brown Reg104A is one of the few IC regulators that has suitably low noise for frequency synthesis.

However, at the very limits of phase noise performance, the squaring technique is inferior to a sine wave.  Not by alot, but enough that I need to stick with a sinusoid.  Not to mention the other modules in the system are expecting a sine wave.

Thanks,

Clay