Cartridge dynamic behaviour

[gpapag]

Hi all

Tarnished contacts cleaning is the first thing I did.
I haven’t tried putting the HD in the freezer. I read somewhere that this may damage the heads if some ice forms inside.
Today I bought a used HD (for 25Euros) same P/N as mine, same firmware.
I tested it and it was OK.
Then I took out the logic board and installed it on mine. The disk remained unlisted under Windows. The bootup menu was listing this HD as failed.
The irony is that the Seagate diagnostic tools for Windows list the HD and all tests show it as healthy.
Then I installed on this logicboard the ROM IC that I removed from mine.
Now the HD is temporary listed under Windows but any action on it is denied due to I/O error as the message says. (the same message that was initially displayed before I started doing anything. The spinning sound is still click free.
I don’t think I can do something more with this (except for the freezer trick as the last one).
>obituary end.

Yesterday I found an old dump of my technical data from this HD (a mere 56GB from Dec 2014).

Time to start collecting new data.🙂

George

 

[Hans Polak]

Hi all

I don’t think I can do something more with this (except for the freezer trick as the last one).
>obituary end.

Yesterday I found an old dump of my technical data from this HD (a mere 56GB from Dec 2014).
Time to start collecting new data.🙂

George

This means a farewell to many years of blood, sweat and tears.
I feel sorry for you.


Hans

 

[gpapag]

No blood in that bloody data.😀
I feel sorry for myself too but then I always do
🙂

George

 

[luckythedog]

I don’t think I can do something more with this (except for the freezer trick as the last one).
>obituary end.

HDDs have inbuilt diagnostics called SMART, and if the interface is working it's perhaps worth putting the drive back to its original configuration and reading the smart data via freeware SW which runs on the PC?

In some drives, part of the firmware is written to the disc, and it has to boot. Also PCBs can't necessarily be swapped between drives of the same type, serial number checks, servo params and defect maps are hard written to the platters factory build time.

Whilst there's even a small chance, I'd still encouraget trying to read SMART data to see what's going on, you never know it still might be file system corruption? And, if you can boot to DOS on the internal drive, and the external drive hardware will mount for DOS, run chkdsk on the external drive to report/fix file system errors? It's all still DOS under the shiny clothes.


LD

 

[gpapag]

Back to the subject of the thread.
Measurements done with REW sw.
One set of measurements with the cartridge as shown on schematic.
Another set of measurements with a short in place of the cartridge coil.
Both measurement sets exported as txt files and imported into MS Excel. No smoothing applied.
At the diagrams you see the result of [cartridge set] – [short set].
This subtraction removes any jig’s freq response and phase influence from the result.

George

 

[DF96]

It's all still DOS under the shiny clothes.

Windows ME was the last version which was based on DOS. Since then the base has been Windows NT, which was a complete rewrite allegedly based somewhat on VAX/VMS concepts.

 

[scottjoplin]

I have tried any remedy trick I found on youtube.
Next action is hammer it, then pour some alcohol over the remains, throw a match and watch the scene

YouTube

 

[Hans Polak]

Back to the subject of the thread.
Measurements done with REW sw.
One set of measurements with the cartridge as shown on schematic.
Another set of measurements with a short in place of the cartridge coil.
Both measurement sets exported as txt files and imported into MS Excel. No smoothing applied.
At the diagrams you see the result of [cartridge set] – [short set].
This subtraction removes any jig’s freq response and phase influence from the result.

George

George,

Great set of measurements.
What are your conclusions and how should this information be used in relation to dynamic cartridge behaviour.

Hans

 

[gpapag]

Next, Stanton MK V Impedance measurement.
Again, measurements done with REW sw. Measurement sets exported as txt files and imported into MS Excel. 1/6 oct smoothing applied.
First three attachments is result of measurement jig’s characterization with calibration resistors. Not very bad for using a single reference resistor across so wide an impedance range.

George

 

[gpapag]

George,

Great set of measurements.
What are your conclusions and how should this information be used in relation to dynamic cartridge behaviour.

Thank you Hans

The excitation signal was from –14dB to +41dB ref 5mV, enough to cover the dynamics of a musical crescendo from p to fff
Within this signal range these measurements don’t show any change in behavior. Maybe there might be something at an even lower excitation level due to the core permeability nonlinearity at very low flux levels (initial permeability).
A secondary observation is that the moving parts of the motor don’t affect the measurements almost at all, another indication of very weak reciprocity.
Yet, the metal shielding of this cartridge affect the performance above 1kHz quite a lot.

George

 

[gpapag]

Continuation of post #189
I extracted the real and imaginary parts of the Z modulus.
It is good that there is close match between the measurements obtained from the LCR meter and those from the soundcard+active jig
Note: The 100kHz data for the soundcard is nonvalid. It is only an estimation through visually extending the curves from 20kHz to 100kHz)

George

 

[gpapag]

What is the measurement level, LCR meters tend to test at far higher levels than normal operation?

David I measured it. It’s a sinewave with amplitude varying depending on the DUT’s impedance.

George

 

[davidsrsb]

Looks like a 600mV RMS source with 1k series resistor

 

[gpapag]

Shure M97xE response

George

 

[gpapag]

Shure M97xE impedance

George

 

[gpapag]

Pickering 950EE MK II response

George

 

[gpapag]

Pickering 950EE MK II impedance

George

 

[gpapag]

Audio-technica AT110E response

George

 

[gpapag]

Audio-technica AT110E impedance

George

 

[gpapag]

AKG P8ES response

George