Re: Scoping of Secondaries

On this subject, Steve writes...
> 1. You should turn all your equipment on and let it warm up for at least 
> 1/2 to 1 hour before using it.  I was sitting there watching my frequency 
> generator change frequency by a few Hz every couple seconds for 
> quite a while after I turned it on.

> 2. Series resistance does make a difference.   I have a 0-10 mHz 
> Hewlett Packard signal generator that has 75 ohm and 600 ohm 
> outputs.  When I used either the 600 ohm output from the signal 
> generator or the cable that has the 1K resistor wired in series , I 
> measured Q's in the neighborhood of 30-50.  When I used the 75 ohm 
> output with a regular RG59 coax cable and no series resistor, I got a Q 
> of 200.
You'll shortly see some data measured using a near voltage source.

> This raises some other questions.  I'm assuming that a signal 
> generator with an even lower impedence would give an even more 
> accurate value for Q, but since I have what I have, is there any way to 
> compensate for this resistance?  Also, rather than just believing the 
> label that says 75 ohms by the output jack, what can I do to confirm or 
> compute the actual impedence of my signal generator?  Would I be 
> able to measure the open circuit voltage and the short circuit current (at 
> say, 60Hz) and use these values to calculate the internal resistance, or 
> is there something more complicated involved?
(a) Add a buffer amp (I've outlined my generator design in the post.
(b) Measure drops into various impedances (L,C, and R) at different