FW version 0.10.19b using sark plots bad data displayed

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william gravett

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Apr 30, 2020, 10:27:48 AM4/30/20
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I am trying to measure parameters on my 160M vertical. I tried the osl calibration and all seemed to go well....however, when I connected to antenna
and used SARK plots and computer control on the device, I get two horizontal parallel lines which I know are incorrect. (measuring vswr and z)
I tried measuring my GAP vertical and also my hex beam and got bogus indications again. 

I had similar indications some years ago and the tech at steppIR said sounds you need a osl cal, which I performed and all worked fine.

I use the 160m preset frequencies on sark plots.

Any suggestions much appreciated.

Bill, W5PGZ

Melchor Varela

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May 1, 2020, 2:39:09 AM5/1/20
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Hello Bill,

Do you obtain the same readings when measuring from the device directly?
Could you please capture a screenshot of the SARK Plots screen and from the device as well, if possible?

Thank you,
Melchor EA4FRB

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william gravett

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May 1, 2020, 7:12:21 AM5/1/20
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I get the same indications on the sark 110 as sark plots. Sometimes , I get a trace where the vswr and z lines are superimposed on top of each other. Before I did the latest OSL cal, the device gave reasonable results (using an older osl cal info).I will try to get screen shots and send to you...have never gotten screen shots before before.
Bill, W5PGZ

On Friday, May 1, 2020 at 1:39:09 AM UTC-5, EA4FRB wrote:
Hello Bill,

Do you obtain the same readings when measuring from the device directly?
Could you please capture a screenshot of the SARK Plots screen and from the device as well, if possible?

Thank you,
Melchor EA4FRB

El jue., 30 abr. 2020 a las 16:27, william gravett (<wgrav...@gmail.com>) escribió:
I am trying to measure parameters on my 160M vertical. I tried the osl calibration and all seemed to go well....however, when I connected to antenna
and used SARK plots and computer control on the device, I get two horizontal parallel lines which I know are incorrect. (measuring vswr and z)
I tried measuring my GAP vertical and also my hex beam and got bogus indications again. 

I had similar indications some years ago and the tech at steppIR said sounds you need a osl cal, which I performed and all worked fine.

I use the 160m preset frequencies on sark plots.

Any suggestions much appreciated.

Bill, W5PGZ

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william gravett

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May 1, 2020, 9:28:56 AM5/1/20
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sark__02.bmp

william gravett

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May 1, 2020, 9:32:49 AM5/1/20
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I am having trouble getting a proper screen shot of sark plots.I get only a partial picture of the plot.sorry.
it matches this bmp from the device
Bill, W5PGZ

william gravett

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May 1, 2020, 9:59:19 AM5/1/20
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I get the same trace on the device with nothing connected to it.
Bill, W5PGZ

william gravett

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May 1, 2020, 10:01:16 AM5/1/20
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Also, if I wiggle the input connector, I get no indication of noise on the display.
Bill, W5PGZ

melchor...@gmail.com

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May 1, 2020, 10:43:40 AM5/1/20
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Please follow the troubleshooting instructions described at: http://www.sark110.com/resources/repairs/input-stage

This will allow to determine if there is a hardware issue in your unit.

 

If results are ok, try to repair the internal drive of the sark110 using the Windows “scan and repair drive” tool (see http://www.sark110.com/resources/repairs/formatting-the-internal-drive). It may happen that there is an error in the drive and the calibration files not read correctly.

 

It will also help if you make a copy of the files in the drive of your unit and send to me for analysis.

 

Thank you,

Melchor EA4FRB

william gravett

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May 1, 2020, 2:23:47 PM5/1/20
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Hardware tests all good...formatted internal drive. Unfortunately, lost files. Can you please send me a set. Thanks
Bill, W5PGZ

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melchor...@gmail.com

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May 1, 2020, 2:53:24 PM5/1/20
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I can provide a set, but the calibration files have coefficients adjusted for the specific unit and connector arrangement, so they would not work properly on your unit. Anyway, you can solve this problem by performing the Detector Calibration and then the OSL calibration; from your previous emails I understand that you have a OSL cal set. Please let me know if the problem is solved after calibration.

Melchor, EA4FRB

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william gravett

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May 2, 2020, 9:00:10 AM5/2/20
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Have tried everything I know to do including osl/detector cals. The cals all went as expected. No change in performance...swr and Zs traces are horizontal and superimposed from 1.8 to 2.0 mhz.
Suggestions ? (my mfj 259 gives reasonable readings )
73,
Bill, W5PGZ

melchor...@gmail.com

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May 2, 2020, 1:42:15 PM5/2/20
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Could you send me the files of the internal drive of your device to check if the contents of the calibration files and settings are ok?

 

Thanks,

william gravett

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May 3, 2020, 8:49:24 AM5/3/20
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detcalib.dat
oslcalib.dat
oslcalib.dat

melchor...@gmail.com

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May 3, 2020, 12:10:19 PM5/3/20
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Hello Bill,

 

Thank you for the files. I’ve observed that the OSL calibration file (oslcalib.dat) has wrong coefficients. I don’t know why, but it looks like the load used for the open condition has a short; at least, I was able to reproduce a similar effect using a short load as the open load during OSL cal. Is it possible that you have a defective open load? But in this case I wonder why the load indicator did not show a bad condition.

 

As an immediate workaround just for test, you could replace the calibration file by the attached one that I’ve prepared (this is calibrated in the same freq range from 1.8 to 2MHz). The readings will not be fully accurate, but at least the indications should not be stuck to VSWR:1.0 and |Z|:50.

 

Best regards,

oslcalib.dat

John G3PQA

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May 4, 2020, 6:15:08 AM5/4/20
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Bill,
Maybe a silly question and I am sure you have done this, but have you checked your test cable and calibration loads with a test meter in case of faults?
John

william gravett

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May 4, 2020, 8:11:30 AM5/4/20
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Thanks, John
All cables/connectors good. Melchior has been great sticking with me and happy to say, unit is now working with a  ocd cal file he sent to me.
73,
Bill, W5PGZ

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