Date: Tue, 22 Apr 2003 09:07:24 -0500 (CDT)
From: Giles Novak 
To: "Calisse, Paolo (South Pole)"
Subject: Re: driving the chopper (fwd)

Hi Paolo,

I found the old notes on how to set up the 33120A in the mode we want.

I send then just in case you should need them (but i hope you don't)

my memory is that they didn't quite work, but Bob L. had to change them
a little to get them to work properly.  I will look through the logs and
see if Bob L. made any notes about how his procedure differed from what is
in these notes.

i will also post this stuff to the web page.  

- Giles

---------- Forwarded message ----------
Date: Mon, 20 Dec 1999 17:37:09 -0800 (PST)
From: Darren Dowell
To: Giles Novak
Subject: Re: driving the chopper


Here are the notes about using the HP 33120A from Walter, an undergraduate
in our group.  The notes look correct.  I would only add the general
comment about the unit that it powers up in "50 ohm" output termination
mode.  If you are driving something with high input impedance, the
voltages will be off by a factor of 2.  Change to "high z" mode under
the "sys" menu.

Good luck.




1.) Plug the TTL source into the burst modulation input on the back of the
function generator.
2.) Generate an arbitrary wave form.
3.) Set the generator into external gated burst mode.
4.) Set the DC offset to whatever value you want for low TTL signal.
5.) Set the arbitrary waveform amplitude to (desired high TTL signal level
- DC
offset) * 2.
In depth

Follow the instructions in Chapter 3 of the function generator manual on
arbitrary waveforms.
The waveform should have 8192 points. Using line edit, the starting point
should be 0 with value +1. The ending point should 
be 8191 with value +1. After these are entered and the waveform is
go to the point edit feature and change the
value for point 8191 to -1. (Note that you may want to save this waveform
you plan on using it often.)

Set the waveform used to arbitrary. (Push the arbitrary button)
Set burst count to 5. (In the menu system)
Set freq to 5MHz.
Set the burst source to external gated. (In the menu system)