[time-nuts] Input voltage for Zeeman on 5061A

Tom Van Baak tvb at leapsecond.com
Sat Jan 22 17:35:39 UTC 2005


John,

Can you quantify that? How many minor divisions
on the C-field dial and what meter levels do you get
for the 3 peaks and 2 valleys between the peaks?

Also try recording to 9 or 10 digits the 5 MHz output
at each peak/valley.

I want to clarify something mentioned a while back.
The peak(s) and valleys you see when performing a
Zeeman calibration are the narrow ~500 Hz wide
center peak. See:
http://www.leapsecond.com/pages/cspeak/image003.gif
and
http://www.leapsecond.com/pages/cspeak/image004.gif

These are not the broad ~40 kHz separated 7 peaks as in:
http://www.leapsecond.com/pages/cspeak/image001.gif

/tvb

----- Original Message -----
From: "John Ackermann N8UR" <jra at febo.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Saturday, January 22, 2005 08:57
Subject: Re: [time-nuts] Input voltage for Zeeman on 5061A


> I tried the 42.82kHz frequency and wasn't able to see any peaks or dips
> at all.  53.53 gives peaks and dips, but not very pronounced.
>
> John
> ----
>
> Chuck Harris wrote:
>
> > The Zeeman frequency is a characteristic of the tube.  Most FTS tubes
> > have their main Zeeman peak at 42.820kHz, and the two peaks on either
> > side are at 41.800kHz, and 43.800kHz.
> >
> > 1 Vrms is what the 5061 wants to see (The Zeeman input is a 50 ohm load
> > IIRC).
> >
> > -Chuck
> >
> > John Ackermann N8UR wrote:
> >
> >> Anyone know how much voltage you need to drive the Zeeman input on
> >> the 5061A?  I just tried to set mine and found that the maximum
> >> output from my 3325A (3V RMS) was barely enough to see any wiggling
> >> at all on the beam current meter  I have another generator that goes
> >> up to 6V and that got me a bit more, but even then only a few meter
> >> divisions between peak and dip.
> >>
> >> Either I need a heftier generator (or maybe an impedance step-up), or
> >> we're back to the question of what is the right Zeeman frequency for
> >> an FTS tube in an HP chassis.
> >>
> >> Thanks,
> >>
> >> John







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