[time-nuts] Zeeman Audio Source?

[Chuck Harris]

Hi Brooke,

It shouldn't be that hard for you to get 1 Vrms into 50 ohms, it is only
20mW.  Your HP204 is designed to drive 600 ohms, so it would like a tiny
little transformer to match it down to 50 ohms, or even close.

Or, you could make yourself an emitter follower using most any small
NPN transistor.  Or any modern opamp...  Amplitude accuracy isn't important
here.  (frequency is, though)  I use an HP3336B synthesizer's 75 ohm
output to drive mine.

-Chuck Harris

Brooke Clarke wrote:
> 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?
> 
> The HP manual says the frequency should be 42.82 kHz for zero offset.  
> There is a table listing a number of other frequencies that give 
> different offsets.  This was back in the days when a second got a new 
> definition each year, hence the different offsets, but today zero offset 
> is the standard.
> 
> Have Fun,
> 
> Brooke Clarke, N6GCE