[Elecraft] NZ7C: Setting up a "lab" (off-topic)

[Don Brown]

Hi

I downloaded the spec on the 33120A to refresh my memory. =20

Problem #13 - 15 MHz upper limit of generator won't go to 28 mHz
problem #34 - this is 2 micro volts into 50 ohms the minimum out of the g=
enerator is 50 mVpp you could use a step attenuator to reduce the level b=
ut good ones with low leakage are very expensive and I can guarantee the =
generator will have more leakage than this. Function generators are not u=
sually designed with low leakage RF outputs because they are used a high =
levels. You need a good RF generator with a well shielded output and atte=
nuator to get to the microvolt level.

My point was not say the generator would not do most of the requirements =
just that a cheap one would do much less. As this is a teaching situation=
 by changing the requirements to fit what ever equipment is available sea=
ms the thing to do rather spending a lot of money on equipment that may n=
ot get used after the class work. =20

However there is a lot of good old used equipment out there if you can ma=
ke it work. I bought a 1.2 GHz HP spectrum analyzer that sold for over $2=
0,000 new in 1985 on ebay for $800 a few months ago and it is in mint con=
dition. Makes a nice addition to my RF bench.


Don
----- Original Message -----
From: Lyle Johnson
Sent: Sunday, April 07, 2002 3:03 PM
To: Don Brown
Subject: RE: [Elecraft] NZ7C: Setting up a "lab" (off-topic)

Hello Don!

I checked all these functions and I don't see one that the specified HP
33120A won't do.  Which function(s) do you think is(are) beyond its
capabilities?

Just curious,

>
> The study also requires a frequency generator and mentions the HP 33120=
A
> 15MHz function generator. Well, this little baby is $1700 new. Dah, I
> don't THINK so folks - I'm more interested in something like $50 used.
> I've summarized the typical uses the "lab work"  demands of the functio=
n
> generator by the book's Problem Numbers.
>
> Knowing that this is what is required, can anyone suggest a piece of
> equipment that would meet my needs and could be had very cheaply? Thank=
s
> again.
>
> Problem 3A: set for 20Hz, 1Vpp square wave
> Problem 4: 1MHz, 5Vpp sine wave with modulation depth of 70% - need a
> synch output connected to the oscilloscope.
>
> Problem 5: 1kHz, 5Vpp square wave    vary 100kHz to 30kHz and 100mVpp
> Problem 10: set for %V pulses with 5ns width that repeat at a feq of
> 20kHz
> Problem 13: 7MHz to 28MHz,10Vpp
> Problem 14: Set to 4,913,500 Hz sine wave with .5Vpp amplitude. Must be
> able to change feq in 1Hz steps
>
> Problem 15: 7MHz sine wave, 5Vpp
> Problem 17: 600Hz sine wave, 25mVrms
> Problem 19: 1kHz square wave (50 ohm function generator set to 4Vpp wit=
h
> DC offset of 2V)
> Problem 20: 20Hz square wave; 5Vpp
> Problem 21: 7MHz sine wave, 2V with .5V offset
> Problem 34 input power of 100fW at freq between 7020 - 7030kHz and
> ability to create noise (-30dBm in this case
>
>
> Thanks folks - 73/Tim Logan NZ7C


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