[time-nuts] "The Penultimate HP5065 A15"

[Poul-Henning Kamp]

--------
Magnus Danielson writes:

> If that is the range you aim to improve, then I strongly recommend you
> do re-read the postings I did about phase noise in detector range, as I
> have showed that phase-noise get's mixed down to DC and increase the
> noise there. With very ugly and hand-wavey hack I was able to
> significantly reduce that noise essentially by cleaning up the
> phase-noise.

Ohh, absolutely.

My plan is to put a modulated DDS synth in to get a much more modern
detector system.

But right now the zener on my a15 is better at measuring temperature
than holding voltage stable, so I'm addressing that first.

See the 3rd graph here:

	http://phk.freebsd.dk/hacks/HP5065A/20150908_a15/

> > > I would go for the LTZ1000 if you can. The LM399 has gone out of
> >> fashion for a reason: [...]
> > Yes, I know, being also a volt-nut :-)
>
> I have not yet jumped down that rabbit-hole as I am by far not done with
> the current one. :)
>
> I've been looking at the LTZ1000 and one day I may get some.

You *really* want the version of it which is packaged in the attractive
and *incredibly* useful "HP3458A" cabinet :-)

-- 
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.