[time-nuts] 60 Hz measurement party

[Mark Spencer]

At the suggestion of another member of the list I added a low pass filter to the 

input of the HP5370B and I also connected the door bell transformer to an un 
shared branch circuit.   After making these changes noise in the readings seems 
to have gone away.




----- Original Message ----
From: Jim Lux <jimlux at earthlink.net>
To: time-nuts at febo.com
Sent: Mon, June 27, 2011 9:34:36 PM
Subject: Re: [time-nuts] 60 Hz measurement party

On 6/27/11 9:43 AM, Mark Spencer wrote:

> I'm not sure if the results I am seeing are  valid or not.    My signal source
> is a 16 volt doorbell transformer that feeds a voltage divider which in turn
> feeds my 5370B with an approx 2 volt sine wave.  Setting the trigger point on
> the 5370B to 0 volts appears to provide the best results and the sine wave 
from
> the voltage divider looks to be clean on my scope.  But I'm wondering if 
>changes
> in line voltage could be confusing things.
> 

That's sort of why I was thinking of the sound card approach.. you sample it, 
fit a sinusoid, and get the zero crossing time from the parametric fit.

Doorbell transformers have a lot of leakage inductance to limit the current (so 
that shorting the output doesn't burn it up)

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.