Re: "Sampler??"

On Tue, 30 Jul 2024 19:21:28 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:

On Tue, 30 Jul 2024 10:39:37 -0700, john larkin wrote:
>

On Tue, 30 Jul 2024 08:58:35 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
 

On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote:
>

On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john
larkin <jlarkin_highland_tech> wrote in
<72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>:
 

On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
>

On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened
Cursitor Doom <cd999666@notformail.com> wrote in
<v86dsp$3n74$1@dont-email.me>:
>
>

I still can't see where the 'sampling' bit comes into it.
AFAICT, there's are two signals into this thing and one signal out.
The signal from the LHS is passed through a very fast diode which
generates harmonics from that fundamental. The signal from the RHS
is unmodified and mixed with the desired harmonic to give the
necessary output signal which is then filtered to get rid of the
unwanted mixing products. If that's all correct, as I believe it is,
where does any *sampling* come into it?

>
A 'sampler' is fact a non-linear mixer.

>
In the audio world, a "mixer" is a linear summer.
>
In RF, a mixer is usually a multiplier, typically a 4-quadrant diode
thing or a Gilbert cell type circuit. Or a 2-quadrant thing like a
pentode. Or even a single diode. All do some flavor of multiplying.
>
Some mixers inherently multiply a signal by a square wave, which
resembles other multiplier-type things once you lowpass filter the
output. That's a "synchronous detector", which we usually do in an
FPGA.
>
A sampler is a signal multiplier too.
>
These are all variations on the basic idea of multiplying two signals.

 
A the word 'mixer' in RF is not the same as a multiplier,,
Multipliers are like harmonic generating stages say you have a 1 MHz
distorted sine wave and then a second stage tuned at 3 MHz,.. turned
to third harmonic.
 
mamamatical speaking RF mixing is indeed multiplication.
 
Like Shakepierce once said:
 "What's in a name..." CocaCola wihout coke

>
I think in this context, HP is using the term "sampler" to mean
something which 'sniffs' a small amount of a signal for testing
purposes. Like a few turns of wire around a transmission line will
'sniff' a small sample of what's going on in the line.
Where I went wrong was rigidly thinking HP meant 'sampling' in the
manner a sampling oscilloscope works. That's what threw me. I tend to
interpret things very literally. :(

 
The sampler in the SA schematic is precisely the sort of sampler used in
a sampling scope. It contains a step-recovery diode impulse generator
and no doubt some sampling diodes.

>
How can you say that when you haven't seen the schematic? If you've been
able to find it online somewhere then kindly post a link to it here.

You posted an excerpt from the HP manual where the sampler is
described.