�

Hi all,

I have reverse-engineered the HP BASIC Code for the HP 4195A adjustment program, 04195-65009. I translated it to Python, using a Prologix GPIB/USB adapter.
The program can be downloaded here:

https://hb9fsx.ch/wordpress/wp-content/uploads/2017/11/Cal_4195A.zip

It is not yet perfect, but it works (at least it did so for me), and I used it to calibrate my 4195A. It would be great if some group members could help me cross-checking it with the original HP BASIC code, but I am unsure whether I can upload that code to the group.

By the way, my 4195A calibrates nicely with this program, but I found out two things:
a) the source output flatness is not perfect (+/-1 dB approx.)
b) there is a sudden step of -1dB in the source output power between 9.999MHz and 10.000MHz.

Required for the calibration:
- a signal generator like the 8662A, 8663A or similar (can be easily extended in the Python code)
- a power meter like the 436A, 437A or 438A

Comments welcome. I know the program is not yet perfect, but I saw that some group members asked for the adjustment program some time ago, and probably others are interested as well, so I thought I could share it.

Best
Tobias HB9FSX

On 11/03/2017 08:37 AM, Tobias Pluess tobias.pluess@...
[hp_agilent_equipment] wrote:

it would be interesting if you could measure your signal source's flatness.
Go to SPECTRUM mode and connect a cable between S1 output and R1 input,
set R1 attenuator to 20 dB and then enable the source on output S1. Then
AUTOSCALE.
It would be interesting to see what the flatness on your unit is. I will
measure it also such that we can compare. I have the gut feeling that my
source is quite bumpy, about +/- 1 dB....

I will try this on my 4195A, if you're interested.

Also, I've downloaded and will take a look at your Python code.

-Dave

�

Hi Tam
it would be interesting if you could measure your signal source's flatness.
Go to SPECTRUM mode and connect a cable between S1 output and R1 input, set R1 attenuator to 20 dB and then enable the source on output S1. Then AUTOSCALE.
It would be interesting to see what the flatness on your unit is. I will measure it also such that we can compare. I have the gut feeling that my source is quite bumpy, about +/- 1 dB....

Tobias

---

From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Friday, November 03, 2017 11:28
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP 4195A adjustment program

�

Hello,

having neither SigGen nor Power Meter, but owning a 4195A, I wanted to offer to help if I can in any way.

Tam

With best regards
Tam Hanna
---

NEW: Enjoy electronics? Like seeing oscilloscopes get repaired? Please subscribe to my new YouTube channel -> http://www.youtube.com/user/MrTamhan

On 03.11.2017 08:47, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:

�

Hi all,

I have reverse-engineered the HP BASIC Code for the HP 4195A adjustment program, 04195-65009. I translated it to Python, using a Prologix GPIB/USB adapter.
The program can be downloaded here:

https://hb9fsx.ch/wordpress/wp-content/uploads/2017/11/Cal_4195A.zip

It is not yet perfect, but it works (at least it did so for me), and I used it to calibrate my 4195A. It would be great if some group members could help me cross-checking it with the original HP BASIC code, but I am unsure whether I can upload that code to the group.

By the way, my 4195A calibrates nicely with this program, but I found out two things:
a) the source output flatness is not perfect (+/-1 dB approx.)
b) there is a sudden step of -1dB in the source output power between 9.999MHz and 10.000MHz.

Required for the calibration:
- a signal generator like the 8662A, 8663A or similar (can be easily extended in the Python code)
- a power meter like the 436A, 437A or 438A

Comments welcome. I know the program is not yet perfect, but I saw that some group members asked for the adjustment program some time ago, and probably others are interested as well, so I thought I could share it.

Best
Tobias HB9FSX

�

Hello Gang,

please have mercy with an old pharte - but I can not, for the life of myself, find the autoscale button.

I set the source of my 4195A to 0DB, and first checked it on my trusty old Iwatsu...which gave me really odd waveforms. When connected R1->S1 with a cable, all I got was an occasional complaint about input overload.

Tam

With best regards
Tam Hanna
---

NEW: Enjoy electronics? Like seeing oscilloscopes get repaired? Please subscribe to my new YouTube channel -> http://www.youtube.com/user/MrTamhan

On 03.11.2017 13:37, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:

�

Hi Tam
it would be interesting if you could measure your signal source's flatness.
Go to SPECTRUM mode and connect a cable between S1 output and R1 input, set R1 attenuator to 20 dB and then enable the source on output S1. Then AUTOSCALE.
It would be interesting to see what the flatness on your unit is. I will measure it also such that we can compare. I have the gut feeling that my source is quite bumpy, about +/- 1 dB....

Tobias

---

From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Friday, November 03, 2017 11:28
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP 4195A adjustment program

�

Hello,

having neither SigGen nor Power Meter, but owning a 4195A, I wanted to offer to help if I can in any way.

Tam

With best regards
Tam Hanna
---

NEW: Enjoy electronics? Like seeing oscilloscopes get repaired? Please subscribe to my new YouTube channel -> http://www.youtube.com/user/MrTamhan

On 03.11.2017 08:47, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:

�

Hi all,

I have reverse-engineered the HP BASIC Code for the HP 4195A adjustment program, 04195-65009. I translated it to Python, using a Prologix GPIB/USB adapter.
The program can be downloaded here:

https://hb9fsx.ch/wordpress/wp-content/uploads/2017/11/Cal_4195A.zip

It is not yet perfect, but it works (at least it did so for me), and I used it to calibrate my 4195A. It would be great if some group members could help me cross-checking it with the original HP BASIC code, but I am unsure whether I can upload that code to the group.

By the way, my 4195A calibrates nicely with this program, but I found out two things:
a) the source output flatness is not perfect (+/-1 dB approx.)
b) there is a sudden step of -1dB in the source output power between 9.999MHz and 10.000MHz.

Required for the calibration:
- a signal generator like the 8662A, 8663A or similar (can be easily extended in the Python code)
- a power meter like the 436A, 437A or 438A

Comments welcome. I know the program is not yet perfect, but I saw that some group members asked for the adjustment program some time ago, and probably others are interested as well, so I thought I could share it.

Best
Tobias HB9FSX

�

Hi Tam

I'm sorry for my late reply. I was a bit busy these days.
I have made two screen dumps of my 4195A, one with the full span 0 to 500 MHz, and one narrow span with 10 MHz center. One can clearly see that there is a significant dip at 10 MHz, and the flatness is not very very good.

https://hb9fsx.ch/wordpress/wp-content/uploads/2017/11/fullspan.png

https://hb9fsx.ch/wordpress/wp-content/uploads/2017/11/smallspan.png

I tried really hard to properly calibrate my unit, but I cannot get rid of that dip at 10 MHz, and I cannot improve the flatness. :-(

Best
Tobias HB9FSX

---

From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Sunday, November 05, 2017 23:15
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP 4195A adjustment program

�

Hello,

found it. The waveforms look interesting to say the least.

Tobias and gang: can I simply email you a zip with the JPEGs? Or should I put them on my Instagram?

Tam

With best regards
Tam Hanna
---

NEW: Enjoy electronics? Like seeing oscilloscopes get repaired? Please subscribe to my new YouTube channel -> http://www.youtube.com/user/MrTamhan

On 05.11.2017 23:09, Tam Hanna tamhan@... [hp_agilent_equipment] wrote:

�

Hello Gang,

please have mercy with an old pharte - but I can not, for the life of myself, find the autoscale button.

I set the source of my 4195A to 0DB, and first checked it on my trusty old Iwatsu...which gave me really odd waveforms. When connected R1->S1 with a cable, all I got was an occasional complaint about input overload.

Tam

With best regards
Tam Hanna
---

NEW: Enjoy electronics? Like seeing oscilloscopes get repaired? Please subscribe to my new YouTube channel -> http://www.youtube.com/user/MrTamhan

On 03.11.2017 13:37, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:

�

Hi Tam
it would be interesting if you could measure your signal source's flatness.
Go to SPECTRUM mode and connect a cable between S1 output and R1 input, set R1 attenuator to 20 dB and then enable the source on output S1. Then AUTOSCALE.
It would be interesting to see what the flatness on your unit is. I will measure it also such that we can compare. I have the gut feeling that my source is quite bumpy, about +/- 1 dB....

Tobias

---

From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Friday, November 03, 2017 11:28
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP 4195A adjustment program

�

Hello,

having neither SigGen nor Power Meter, but owning a 4195A, I wanted to offer to help if I can in any way.

Tam

With best regards
Tam Hanna
---

NEW: Enjoy electronics? Like seeing oscilloscopes get repaired? Please subscribe to my new YouTube channel -> http://www.youtube.com/user/MrTamhan

On 03.11.2017 08:47, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] wrote:

�

Hi all,

I have reverse-engineered the HP BASIC Code for the HP 4195A adjustment program, 04195-65009. I translated it to Python, using a Prologix GPIB/USB adapter.
The program can be downloaded here:

https://hb9fsx.ch/wordpress/wp-content/uploads/2017/11/Cal_4195A.zip

It is not yet perfect, but it works (at least it did so for me), and I used it to calibrate my 4195A. It would be great if some group members could help me cross-checking it with the original HP BASIC code, but I am unsure whether I can upload that code to the group.

By the way, my 4195A calibrates nicely with this program, but I found out two things:
a) the source output flatness is not perfect (+/-1 dB approx.)
b) there is a sudden step of -1dB in the source output power between 9.999MHz and 10.000MHz.

Required for the calibration:
- a signal generator like the 8662A, 8663A or similar (can be easily extended in the Python code)
- a power meter like the 436A, 437A or 438A

Comments welcome. I know the program is not yet perfect, but I saw that some group members asked for the adjustment program some time ago, and probably others are interested as well, so I thought I could share it.

Best
Tobias HB9FSX