Re: Help with Mosfet mixer


David wrote:
Andy,

Does this all sound reasonable ?

Thanks heaps

Regards

David


Andy writes:

Sounds to me like you are well along the road to being the
world's best receiver designer....

One trick that I used myself when using a scope or spectrum
analyzer to probe volltage to check gain :

I would put about a 0.2 ( yes 2/10 ) of a pf capacitor in series
with my probe, whether highz scope or 50 ohm spect analyzer...
This almost completely "unloads" the circuit when the probe touches
it. There is a great signal loss of course, but since the frequency
is the
same for both input and output measurements, the loss is the same
for each measurement. Relative readings are pretty accurate......
I liked using a spect analyzer cause I could turn the sensitivity
way the hell up, and my measurements would be in db.....

Worked well for me... Maybe others here have some favorite
tricks they can share, too....

Andy W4OAH in Eureka, Texas


( If you mowed your yard and found your missing car, you might
live in Eureka, Texas )

.

Relevant Pages

  • Re: MOSFET switching of DC motor at 50V makes isolated 5V ground unstable...
    ... measurements you reported were reasonably accurate. ... > gator clip on the probe, I use a separate cable that plugs into the ... hookup leads soldered directly to the circuit board. ... Please describe how the signals physically get from the optos on ...
    (sci.electronics.design)
  • Re: Measuring the noise floor
    ... > I've been making my noise floor measurements with a rented HP3588 ... > spectrum analyzer and a differrential probe. ... The HP4195A doesn't have the best noise floor. ... The differential probe helps with ground loop problems. ...
    (sci.electronics.design)
  • Re: Andrew Haas
    ... Hell michigan ... probe not the same andy as Phillip from canada said. ...
    (rec.running)
  • Re: galvanic isolation of sensors
    ... measurements of different probes aren't interfering with each other. ... about 0.5" x 1.5" per probe PCB... ... isolation of the inputs, is the CMV really so high that you need it? ... power and can run on batteries. ...
    (comp.arch.embedded)
  • Re: One for the bottleheads
    ... listeners observe and what measurements show, ... Andy ... As ever, you try to blow smoke by dragging in 'measurements', when the ...
    (uk.rec.audio)