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Help Needed- Distortion display using HP334 or equiv.

 

Hi All: a bit off topic, but saw some mention of display of distortion components by John-Paul (in thread about tube scope probes). This was done at Marsntz, and Sequerra back in the day by their analog guy.
In the HP 334 manual, there are tantalizing mentions of this ability, and a diagram showing distortion products from a CRT I suspect. However, there is no hookup diagram, nor instructions on how to accomplish this display feat.
?
Hoping someone has information to connect the proverbial dots here.
?
Thanks in advance!
?
Randy
?
Tek 555, 7834, 7633,7623, HP, Fluke, and others.
 

On Mon, Jan 13, 2025 at 07:47 PM, Randy Newman wrote:
Hi All: a bit off topic, but saw some mention of display of distortion components by John-Paul (in thread about tube scope probes). This was done at Marsntz, and Sequerra back in the day by their analog guy.
In the HP 334 manual, there are tantalizing mentions of this ability, and a diagram showing distortion products from a CRT I suspect. However, there is no hookup diagram, nor instructions on how to accomplish this display feat.
?
Hoping someone has information to connect the proverbial dots here.
?
Thanks in advance!
?
Randy
?
Tek 555, 7834, 7633,7623, HP, Fluke, and others.
?
?
Randy,
It's very simple.? The distortion products are available at the Output jacks at the lower right corner of your 334 meter.? Just use a coax/jumper wires/scope probe to connect the Output from the 334 to your scope vertical input.? The scope will display all of the noise and distortion present in the input signal (after the 334 has been properly tuned, of course).
?
Cheers,
DaveM
 

Hello again,


Sid used the same HP 336, but modified it for improved noise floor, hum and THD.

The generator is also critical, I think he had an HP204 also modified

See Jim Williams Linear Technology note (43?) on low distortion audio generator

HP or Tektronix or other DA all have distortion product output, it is the signal fundamental nulled out of the input.

Scope X- input to DUT

Scope Y- distortion output.

See Tek, AP and HP app notes on audio distortion measurement

Beware of amplifer output overload, use appropriate load and Attenuator

Amicalement

Jon
 

Excellent!
Thanks.

I happen to have a 200CD, stock, so not modified for the low distortion mode.
?

Re: Jim Williams, one of my favorite app note authors.
I used to read them from end to end gleaning lots of good info.
Also Bob Pease!!

Btw: I’m primarily an analog guy. My day job is in a lab where we have all sorts of data buses, as well as some analogs. Lots of integration work, as well as interface design. Keeps my brain functional, and is great fun.

In reality, it’s all analog anyway when you get down to signal propagation anyway.
Also have read Signal propagation books by Dr.Howard Johnson. Great stuff!

Thanks again for the info - I’ll go dredge for Tek & HP App notes - another old favorite. Am familiar with w140 for Tek stuff. Need to brush up on source for HP app notes. Agilent used to host them, but not sure anymore.

Randy

Tek 555, 7834,7633,7623, Data Precision D6100 Waveform Analyzer (M6800 CPU!!), HP, Fluke, and others.

On Tue, Jan 14, 2025 at 9:33?AM Froggie the Gremlin via <jonpaul=[email protected]> wrote:
Hello again,


Sid used the same HP 336, but modified it for improved noise floor, hum and THD.

The generator is also critical, I think he had an HP204 also modified

See Jim Williams Linear Technology note (43?) on low distortion audio generator

HP or Tektronix or other DA all have distortion product output, it is the signal fundamental nulled out of the input.

Scope X- input to DUT

Scope Y- distortion output.

See Tek, AP and HP app notes on audio distortion measurement

Beware of amplifer output overload, use appropriate load and Attenuator

Amicalement

Jon
 

On Tue, Jan 14, 2025 at 04:45 PM, Randy Newman wrote:
Excellent!
Thanks.
?
Thanks again for the info - I’ll go dredge for Tek & HP App notes - another old favorite. Am familiar with w140 for Tek stuff. Need to brush up on source for HP app notes. Agilent used to host them, but not sure anymore.
?
Randy
?
Randy,
Surf over to .? There, you'll find bunches of App Notes, Bench Briefs, manuals for lots of the OLD equipment, catalogs, and a lot of history.
Cheers,
DaveM
 

Thanks! I’ll head over there when I get time .
Those old app notes contain a wealth of information, and were intended to teach users, unlike what we get today.

Just like the the theory of operation sections of the old ( circa 60’s / 70’s) service manuals.
The current ones have little or no info, as “there are no user serviceable parts inside “….

The new scopes are nice , but not something you’d be able to repair like the older ones.

I’ve used some of the high end DSA types (DSA 70804, ?GHz BW) for serial differential data investigations, and it was great, just not repairable. And not small- almost the size of my 555!!!

Thanks again-!

Randy


On Tue, Jan 14, 2025 at 8:04?PM David M via <dgminala=[email protected]> wrote:
On Tue, Jan 14, 2025 at 04:45 PM, Randy Newman wrote:
Excellent!
Thanks.
?
Thanks again for the info - I’ll go dredge for Tek & HP App notes - another old favorite. Am familiar with w140 for Tek stuff. Need to brush up on source for HP app notes. Agilent used to host them, but not sure anymore.
?
Randy
?
Randy,
Surf over to .? There, you'll find bunches of App Notes, Bench Briefs, manuals for lots of the OLD equipment, catalogs, and a lot of history.
Cheers,
DaveM
 

There's the HPWiki here:

Be sure to the HP pix here:
beautiful work


Thanks again for the info - I’ll go dredge for Tek & HP App notes -
another old favorite. Am familiar with w140 for Tek stuff. Need to
brush up on source for HP app notes. Agilent used to host them, but
not sure anymore.
Randy
Randy,

Bill @ PEARL in BC
 

My work with Dick and Sid the ex Marantz tube HiFi designers,



Enjoy


Jon
 

Here’s a video you may enjoy on the topic:
https://youtu.be/EjV-sAW8Ylg?si=OS5NuiZatemu2AGM
 

I remember the Sequerra 1. A tour de force.
II’m still using a Dynaco FM-5 SS tuner from the late 70’s.
Plus, I have a couple of the higher end Yamaha tuners that get more airtime these days.

On Thu, Jan 16, 2025 at 5:38?AM pac1085 via <pac1085=[email protected]> wrote:
Here’s a video you may enjoy on the topic:

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