[time-nuts] Zeeman Audio Source?

[Poul-Henning Kamp]

In message <41E59FFE.9080903 at pacific.net>, Brooke Clarke writes:
>Hi:
>
>I tried to use my HP 204B audio source for the Zeeman test, but
>although it puts out over 5 volts RMS into an open circuit, the
>voltage across the 50 Ohm FTS4060 Zeeman input is only 0.33 Volts,
>not the 1 Volt needed.  Can someone recommend an audio generator,
>hopefully available for a reasonable
>price somewhere?

I broke down and bought a HP33120A, they go for a fair price on
eBay these days.

If you have one, an interesting experiment is to set it to generate
a 1Hz squarewave and then measure the jitter:  It's terrible.

In the squarewave setting they generate a sine and runs it through
a schmit-trigger.

To get good slow square-waves, define a custom curvefrom as a square
and it will be rock solid.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.