Date: Sun, 9 May 2010 15:29:50 -

Author: Rachel Melogno

Subject: Re: Frequency Generator

Post:

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I apologize for asking you this, but I need help.

I would like to unsubscribe from this listserve, but I have been unable to
navigate to the page where I can. Can you please send me the link? Thank
you very much!

-Melogno


On Sun, May 9, 2010 at 2:13 PM, Bernard Cleyet
wrote:

> That is a variation of the original model that created the HP "brothers'"
> company. The oscillator is a negative feed back twin T notch filter w/ a
> tungsten positive feed back amplitude control. GR made a more sophisticated
> (transistorized) model.
>
> I presume your oscillator has a big dial w/ a small one as a reducing drive
> (friction not gear).
>
> bc has several plus a non-working GR one
>
> p.s. the output should be a trasnformer. On some models one may vary from
> the 600 Ohms by changing the taps, IIRC. For one lab exercise I introduced
> an audi matching transformer to obtain a Z of a few ohms.
>
>
> On 2010, May 09, , at 11:27, Marc Zeke Kossover wrote:
>
> >
> > One person suggested (and I lost the name in an email crash) the HP 240C
> Oscillator for $99 used on Ebay. I bought that, and it has worked like a
> dream. It doesn't have a digital display but has dial which doesn't seem to
> be right on, but is close, and a cheap frequency counter seems to work fine
> with it.
> >
> > It has a nice control knob that lets you adjust the frequency very slowly
> and precisely.
> >
> > It is has quite a bit of amplitude but only a high impedance output.
>
>
>

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I apologize for asking you this, but I need help.I would like to un=
subscribe from this listserve, but I have been unable to navigate to the pa=
ge where I can.=A0 Can you please send me the link?=A0 Thank you very much!=

-MelognoOn Sun, May 9, 2010 at 2=
:13 PM, Bernard Cleyet wrote:
That is a variation of the original model that created =A0the HP "brot=
hers'" company. =A0 The oscillator is a negative feed back twin T =
notch filter w/ a tungsten positive feed back amplitude control. =A0GR made=
a more sophisticated (transistorized) model.


I presume your oscillator has a big dial w/ a small one as a reducing drive=
(friction not gear).

bc has several plus a non-working GR one

p.s. the output should be a trasnformer. =A0On some models one may vary fro=
m the 600 Ohms by changing the taps, IIRC. =A0 For one lab exercise I intro=
duced an audi matching transformer to obtain a Z of a few ohms.


On 2010, May 09, , at 11:27, Marc Zeke Kossover wrote:

>
> One person suggested (and I lost the name in an email crash) the HP 24=
0C Oscillator for $99 used on Ebay. I bought that, and it has worked like a=
dream. It doesn't have a digital display but has dial which doesn'=
t seem to be right on, but is close, and a cheap frequency counter seems to=
work fine with it.

>
> It has a nice control knob that lets you adjust the frequency very slo=
wly and precisely.
>
> It is has quite a bit of amplitude but only a high impedance output.




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