Re: HP 8920A spectrum analyser amplitude calibration
Ah! Got it. I shall remember if I should need it.
Rgds
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Show quoted text
On 13 Apr 2020, at 13:13, george edmonds via groups.io <G6HIG@...> wrote:
?
Hi Colin
CLIP stands for Component Layout Information Package, HP speak for circuit diagrams and board layouts. When you get a service manual for later HP kit it is the text only, the interesting stuff is in the CLIP.
Kind regards
George G6HIG
On Monday, 13 April 2020, 11:28:34 BST, Colin Smithers <colin@...> wrote:
Hi George,
?
Now were motoring! I was unaware of Amtronix, thanks. Clearly they must know and perhaps might help.
?
You will have to inlighten me as to what the CLIP is, please?
?
Kind regards
?
Colin
?
From: [email protected] [mailto:[email protected]]On Behalf Of
george edmonds via groups.io
Sent: 13 April 2020 10:32
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration
?
Hi Colin
I do not understand the posting about making manual adjustments, I can see that using the suggested approach for fault finding is valid, but not for adjusting the calibration given that the 8920A is software calibrated only. The calibration constants are held
in none volatile memory in each module which are read into main ram on power up.
As far as I remember the Cal switch just enables and disables the ability to carry out a calibration via the GPIB port.
Prior to 1999 all 8920A's had a mechanical attenuator, which your appears to have. It then became option 055 with the PIN diode attenuator as option 009.
The only remaining commercial support for the 8920A is provided by Amtronix in the US, who do provide full repair and calibration facilities for them.
Are you aware of the information at Amtronix.com/diagnostic/htm?
Do you have the CLIP for the 8920A, I do if you need it.
Regards
George G6HIG
On Monday, 13 April 2020, 07:25:14 BST, Colin Smithers <colin@...> wrote:
Hi George,
?
Just measured, the unit is substantially flat (+/-0.2dB) across the range from 1MHz -500MHz, but with the Main input around -2.2dB and Ant input -2.6dB. But these back my point that for a subsidiary
function this Spec An is very good indeed.
?
The Main input shows >-25dB return loss, I am yet to measure the Ant input.
?
Looking at the Spec An block diagram two things stick out:-
?
-?????????A signal switch near the front with a Cal setting
-?????????A 4-in-1 DAC which seems to control variable gain amp as well as IF filters
?
So I remain thinking that ?I¡¯m on the hunt for a deeply buried Cal routine. Fiddling with loss internally is clearly possible (from another rreply), but only finding the routine would be future
proof.
?
Thanks for info about that HP IEEE 488 program. My Win95 machine does still boot up¡??J
Gonna have to find an IEEE488 card though. Or info on what the code drives.
?
Rgds
?
Colin
?
From: [email protected] [mailto:[email protected]]On Behalf Of
george edmonds via groups.io
Sent: 13 April 2020 00:37
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration
?
Hi Colin
I have also seen your posting on the HP8924 group which has additional information in it.
First it is very important to say at what frequencies you are experiencing the errors, the main reason for this is that the front panel on a HP8920A gives the operating range as 400KHz to 1GHz. This is ONLY true for the original electromechanical attenuator
version, all the ones that I have seen in the UK have had the PIN diode attenuator fitted which in my experience cannot be trusted below 50MHz. HP claimed 10MHz in their dreams.
Most of these test sets were purchased in the UK for analogue cellular use so the use of a PIN diode attenuator was not an issue.
I would first check to see if the input load measures 50 ohms at the N port, if it does then check and re torque the internal hard line SMA's using a torque spanner, this is very important to avoid damage to the SMA's. There were a number of optimal power handling
input loads available, it is not unknown for excess RF power to damage them.
I have not had to work on a 8920A for some years, but as I recall the calibration/adjustment was carried out via the GPIB port using dedicated HP software that would not run on anything later than Windows 95 or possibly 98.
Hope that this helps
George G6HIG
On Sunday, 12 April 2020, 22:18:40 BST, Colin Smithers <colin@...> wrote:
Hi all,
I have an 8920A and the spectrum analyser amplitude level is 3dB out. I have read enough to understand that calibrating this is a bit of a secret. Does anyone know it please?
Similarly for calibrating the power meter.
I have asked the same question on the 8924-series group.
Kind regards
Colin Smithers G4CWH
|
Re: HP 8920A spectrum analyser amplitude calibration
Hi Colin
CLIP stands for Component Layout Information Package, HP speak for circuit diagrams and board layouts. When you get a service manual for later HP kit it is the text only, the interesting stuff is in the CLIP.
Kind regards
George G6HIG On Monday, 13 April 2020, 11:28:34 BST, Colin Smithers <colin@...> wrote:
Hi George, ? Now were motoring! I was unaware of Amtronix, thanks. Clearly they must know and perhaps might help. ? You will have to inlighten me as to what the CLIP is, please? ? Kind regards ? Colin ?
From: [email protected] [mailto:[email protected]]On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 10:32
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration ? Hi Colin
I do not understand the posting about making manual adjustments, I can see that using the suggested approach for fault finding is valid, but not for adjusting the calibration given that the 8920A is software calibrated only. The calibration constants are held in none volatile memory in each module which are read into main ram on power up.
As far as I remember the Cal switch just enables and disables the ability to carry out a calibration via the GPIB port.
Prior to 1999 all 8920A's had a mechanical attenuator, which your appears to have. It then became option 055 with the PIN diode attenuator as option 009.
The only remaining commercial support for the 8920A is provided by Amtronix in the US, who do provide full repair and calibration facilities for them.
Are you aware of the information at Amtronix.com/diagnostic/htm?
Do you have the CLIP for the 8920A, I do if you need it.
Regards
George G6HIG On Monday, 13 April 2020, 07:25:14 BST, Colin Smithers <colin@...> wrote: Hi George, ? Just measured, the unit is substantially flat (+/-0.2dB) across the range from 1MHz -500MHz, but with the Main input around -2.2dB and Ant input -2.6dB. But these back my point that for a subsidiary function this Spec An is very good indeed. ? The Main input shows >-25dB return loss, I am yet to measure the Ant input. ? Looking at the Spec An block diagram two things stick out:- ? -?????????A signal switch near the front with a Cal setting -?????????A 4-in-1 DAC which seems to control variable gain amp as well as IF filters ? So I remain thinking that ?I¡¯m on the hunt for a deeply buried Cal routine. Fiddling with loss internally is clearly possible (from another rreply), but only finding the routine would be future proof. ? Thanks for info about that HP IEEE 488 program. My Win95 machine does still boot up¡??J Gonna have to find an IEEE488 card though. Or info on what the code drives. ? Rgds ? Colin ? From: [email protected] [mailto:[email protected]]On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 00:37
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration ? Hi Colin
I have also seen your posting on the HP8924 group which has additional information in it.
First it is very important to say at what frequencies you are experiencing the errors, the main reason for this is that the front panel on a HP8920A gives the operating range as 400KHz to 1GHz. This is ONLY true for the original electromechanical attenuator version, all the ones that I have seen in the UK have had the PIN diode attenuator fitted which in my experience cannot be trusted below 50MHz. HP claimed 10MHz in their dreams.
Most of these test sets were purchased in the UK for analogue cellular use so the use of a PIN diode attenuator was not an issue.
I would first check to see if the input load measures 50 ohms at the N port, if it does then check and re torque the internal hard line SMA's using a torque spanner, this is very important to avoid damage to the SMA's. There were a number of optimal power handling input loads available, it is not unknown for excess RF power to damage them.
I have not had to work on a 8920A for some years, but as I recall the calibration/adjustment was carried out via the GPIB port using dedicated HP software that would not run on anything later than Windows 95 or possibly 98.
Hope that this helps
George G6HIG On Sunday, 12 April 2020, 22:18:40 BST, Colin Smithers <colin@...> wrote: Hi all,
I have an 8920A and the spectrum analyser amplitude level is 3dB out. I have read enough to understand that calibrating this is a bit of a secret. Does anyone know it please?
Similarly for calibrating the power meter.
I have asked the same question on the 8924-series group.
Kind regards
Colin Smithers G4CWH
|
Re: GPSDO connected to external ref inputs
I have a GPSDO going to a 4 port distribution amp which is connected to a HP 8920A, HP 8594E, 8656B, and HP 53131A. The Ref signal is never turned off but the equipment is turned off daily. Never had a problem
|
Re: HP 8920A spectrum analyser amplitude calibration
CLIP == Component Level Information Pack == Schematics and Parts Lists (no sorry no Theory of Operation sections) ? David ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Colin Smithers
Sent: 13 April 2020 11:28
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration? Hi George, ? Now were motoring! I was unaware of Amtronix, thanks. Clearly they must know and perhaps might help. ? You will have to inlighten me as to what the CLIP is, please? ? Kind regards ? Colin ? From: [email protected] [mailto:[email protected]] On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 10:32
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration ? Hi Colin
I do not understand the posting about making manual adjustments, I can see that using the suggested approach for fault finding is valid, but not for adjusting the calibration given that the 8920A is software calibrated only. The calibration constants are held in none volatile memory in each module which are read into main ram on power up.
As far as I remember the Cal switch just enables and disables the ability to carry out a calibration via the GPIB port.
Prior to 1999 all 8920A's had a mechanical attenuator, which your appears to have. It then became option 055 with the PIN diode attenuator as option 009.
The only remaining commercial support for the 8920A is provided by Amtronix in the US, who do provide full repair and calibration facilities for them.
Are you aware of the information at Amtronix.com/diagnostic/htm?
Do you have the CLIP for the 8920A, I do if you need it.
Regards
George G6HIG On Monday, 13 April 2020, 07:25:14 BST, Colin Smithers <colin@...> wrote: Hi George, ? Just measured, the unit is substantially flat (+/-0.2dB) across the range from 1MHz -500MHz, but with the Main input around -2.2dB and Ant input -2.6dB. But these back my point that for a subsidiary function this Spec An is very good indeed. ? The Main input shows >-25dB return loss, I am yet to measure the Ant input. ? Looking at the Spec An block diagram two things stick out:- ? -?????????A signal switch near the front with a Cal setting -?????????A 4-in-1 DAC which seems to control variable gain amp as well as IF filters ? So I remain thinking that ?I¡¯m on the hunt for a deeply buried Cal routine. Fiddling with loss internally is clearly possible (from another rreply), but only finding the routine would be future proof. ? Thanks for info about that HP IEEE 488 program. My Win95 machine does still boot up¡??J Gonna have to find an IEEE488 card though. Or info on what the code drives. ? Rgds ? Colin ? From: [email protected] [mailto:[email protected]]On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 00:37
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration ? Hi Colin
I have also seen your posting on the HP8924 group which has additional information in it.
First it is very important to say at what frequencies you are experiencing the errors, the main reason for this is that the front panel on a HP8920A gives the operating range as 400KHz to 1GHz. This is ONLY true for the original electromechanical attenuator version, all the ones that I have seen in the UK have had the PIN diode attenuator fitted which in my experience cannot be trusted below 50MHz. HP claimed 10MHz in their dreams.
Most of these test sets were purchased in the UK for analogue cellular use so the use of a PIN diode attenuator was not an issue.
I would first check to see if the input load measures 50 ohms at the N port, if it does then check and re torque the internal hard line SMA's using a torque spanner, this is very important to avoid damage to the SMA's. There were a number of optimal power handling input loads available, it is not unknown for excess RF power to damage them.
I have not had to work on a 8920A for some years, but as I recall the calibration/adjustment was carried out via the GPIB port using dedicated HP software that would not run on anything later than Windows 95 or possibly 98.
Hope that this helps
George G6HIG On Sunday, 12 April 2020, 22:18:40 BST, Colin Smithers <colin@...> wrote: Hi all,
I have an 8920A and the spectrum analyser amplitude level is 3dB out. I have read enough to understand that calibrating this is a bit of a secret. Does anyone know it please?
Similarly for calibrating the power meter.
I have asked the same question on the 8924-series group.
Kind regards
Colin Smithers G4CWH
|
Re: HP 8920A spectrum analyser amplitude calibration
Hi George,
?
Now were motoring! I was unaware of Amtronix, thanks. Clearly they must know and perhaps might help.
?
You will have to inlighten me as to what the CLIP is, please?
?
Kind regards
?
Colin
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]]
On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 10:32
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration
?
Hi Colin
I do not understand the posting about making manual adjustments, I can see that using the suggested approach for fault finding is valid, but not for adjusting the calibration given that the 8920A is software calibrated only. The calibration constants are held
in none volatile memory in each module which are read into main ram on power up.
As far as I remember the Cal switch just enables and disables the ability to carry out a calibration via the GPIB port.
Prior to 1999 all 8920A's had a mechanical attenuator, which your appears to have. It then became option 055 with the PIN diode attenuator as option 009.
The only remaining commercial support for the 8920A is provided by Amtronix in the US, who do provide full repair and calibration facilities for them.
Are you aware of the information at Amtronix.com/diagnostic/htm?
Do you have the CLIP for the 8920A, I do if you need it.
Regards
George G6HIG
On Monday, 13 April 2020, 07:25:14 BST, Colin Smithers <colin@...> wrote:
Hi George,
?
Just measured, the unit is substantially flat (+/-0.2dB) across the range from 1MHz -500MHz, but with the Main input around -2.2dB and Ant input
-2.6dB. But these back my point that for a subsidiary function this Spec An is very good indeed.
?
The Main input shows >-25dB return loss, I am yet to measure the Ant input.
?
Looking at the Spec An block diagram two things stick out:-
?
-?????????A
signal switch near the front with a Cal setting
-?????????A
4-in-1 DAC which seems to control variable gain amp as well as IF filters
?
So I remain thinking that ?I¡¯m on the hunt for a deeply buried Cal routine. Fiddling with loss internally is clearly possible (from another rreply),
but only finding the routine would be future proof.
?
Thanks for info about that HP IEEE 488 program. My Win95 machine does still boot up¡??J
Gonna have to find an IEEE488 card though. Or info on what the code drives.
?
Rgds
?
Colin
?
From: [email protected]
[mailto:[email protected]]On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 00:37
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration
?
Hi Colin
I have also seen your posting on the HP8924 group which has additional information in it.
First it is very important to say at what frequencies you are experiencing the errors, the main reason for this is that the front panel on a HP8920A gives the operating range as 400KHz to 1GHz. This is ONLY true for the original electromechanical attenuator
version, all the ones that I have seen in the UK have had the PIN diode attenuator fitted which in my experience cannot be trusted below 50MHz. HP claimed 10MHz in their dreams.
Most of these test sets were purchased in the UK for analogue cellular use so the use of a PIN diode attenuator was not an issue.
I would first check to see if the input load measures 50 ohms at the N port, if it does then check and re torque the internal hard line SMA's using a torque spanner, this is very important to avoid damage to the SMA's. There were a number of optimal power handling
input loads available, it is not unknown for excess RF power to damage them.
I have not had to work on a 8920A for some years, but as I recall the calibration/adjustment was carried out via the GPIB port using dedicated HP software that would not run on anything later than Windows 95 or possibly 98.
Hope that this helps
George G6HIG
On Sunday, 12 April 2020, 22:18:40 BST, Colin Smithers <colin@...> wrote:
Hi all,
I have an 8920A and the spectrum analyser amplitude level is 3dB out. I have read enough to understand that calibrating this is a bit of a secret. Does anyone know it please?
Similarly for calibrating the power meter.
I have asked the same question on the 8924-series group.
Kind regards
Colin Smithers G4CWH
|
Re: HP 8920A spectrum analyser amplitude calibration
Hi Colin
I do not understand the posting about making manual adjustments, I can see that using the suggested approach for fault finding is valid, but not for adjusting the calibration given that the 8920A is software calibrated only. The calibration constants are held in none volatile memory in each module which are read into main ram on power up.
As far as I remember the Cal switch just enables and disables the ability to carry out a calibration via the GPIB port.
Prior to 1999 all 8920A's had a mechanical attenuator, which your appears to have. It then became option 055 with the PIN diode attenuator as option 009.
The only remaining commercial support for the 8920A is provided by Amtronix in the US, who do provide full repair and calibration facilities for them.
Are you aware of the information at Amtronix.com/diagnostic/htm?
Do you have the CLIP for the 8920A, I do if you need it.
Regards
George G6HIG
On Monday, 13 April 2020, 07:25:14 BST, Colin Smithers <colin@...> wrote:
Hi George, ? Just measured, the unit is substantially flat (+/-0.2dB) across the range from 1MHz -500MHz, but with the Main input around -2.2dB and Ant input -2.6dB. But these back my point that for a subsidiary function this Spec An is very good indeed. ? The Main input shows >-25dB return loss, I am yet to measure the Ant input. ? Looking at the Spec An block diagram two things stick out:- ? -?????????A signal switch near the front with a Cal setting -?????????A 4-in-1 DAC which seems to control variable gain amp as well as IF filters ? So I remain thinking that ?I¡¯m on the hunt for a deeply buried Cal routine. Fiddling with loss internally is clearly possible (from another rreply), but only finding the routine would be future proof. ? Thanks for info about that HP IEEE 488 program. My Win95 machine does still boot up¡??J Gonna have to find an IEEE488 card though. Or info on what the code drives. ? Rgds ? Colin ?
From: [email protected] [mailto:[email protected]]On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 00:37
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration ? Hi Colin
I have also seen your posting on the HP8924 group which has additional information in it.
First it is very important to say at what frequencies you are experiencing the errors, the main reason for this is that the front panel on a HP8920A gives the operating range as 400KHz to 1GHz. This is ONLY true for the original electromechanical attenuator version, all the ones that I have seen in the UK have had the PIN diode attenuator fitted which in my experience cannot be trusted below 50MHz. HP claimed 10MHz in their dreams.
Most of these test sets were purchased in the UK for analogue cellular use so the use of a PIN diode attenuator was not an issue.
I would first check to see if the input load measures 50 ohms at the N port, if it does then check and re torque the internal hard line SMA's using a torque spanner, this is very important to avoid damage to the SMA's. There were a number of optimal power handling input loads available, it is not unknown for excess RF power to damage them.
I have not had to work on a 8920A for some years, but as I recall the calibration/adjustment was carried out via the GPIB port using dedicated HP software that would not run on anything later than Windows 95 or possibly 98.
Hope that this helps
George G6HIG On Sunday, 12 April 2020, 22:18:40 BST, Colin Smithers <colin@...> wrote: Hi all,
I have an 8920A and the spectrum analyser amplitude level is 3dB out. I have read enough to understand that calibrating this is a bit of a secret. Does anyone know it please?
Similarly for calibrating the power meter.
I have asked the same question on the 8924-series group.
Kind regards
Colin Smithers G4CWH
|
Re: Opens and shorts for 4285A LCR meter owners
I found them. :)
Thanks for that! Custom test jigs are now on the to-do list. :D
Jared
On Mon, Apr 13, 2020 at 02:22 PM, Dr. David Kirkby, Kirkby Microwave Ltd wrote:
Hi David.
?
Where did you get the BNC connectors for your open and short?
Were they taken from test fixtures or can they be purchased separately?
Thanks!
?
You can get them on eBay. Search for BNC levers or BNC handles. One does need to cut some BNC plugs up to make these, as you only want the inner part of the plug. I use a grinder and hacksaw.?
?
HP do make some fixtures with 4 levers, and some with none. Two is a compromise.
?
I want to make a fixture that allows one to apply a DC offset of up to 30 kV. That will be a challenge. I will probably restrict its use to a lower specification LCR meter I have, as I wrote not want to risk damaging these. At 30 kV, some precautions will be necessary.?
--
Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@...Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
|
Re: WTB: 3467A Printer module.
I saw that one! :)
I sent a message asking if they'll send to Japan already, just waiting for a reply.
|
Re: WTB: 3467A Printer module.
Jared,
If you hurry, there is one on eBay: item?303533154695
--John Gord
toggle quoted message
Show quoted text
On Sun, Apr 12, 2020 at 07:31 PM, Jared Cabot wrote:
I have a 3567A Logging Multimeter here that I picked up cheap but it is missing the printer module.
Does anyone have a printer module they are willing to sell and send to Japan?
?
Thanks!
|
Re: HP 8920A spectrum analyser amplitude calibration
Hi George,
?
Just measured, the unit is substantially flat (+/-0.2dB) across the range from 1MHz -500MHz, but with the Main input around -2.2dB and Ant input -2.6dB. But
these back my point that for a subsidiary function this Spec An is very good indeed.
?
The Main input shows >-25dB return loss, I am yet to measure the Ant input.
?
Looking at the Spec An block diagram two things stick out:-
?
-?????????
A signal switch near the front with a Cal setting
-?????????
A 4-in-1 DAC which seems to control variable gain amp as well as IF filters
?
So I remain thinking that ?I¡¯m on the hunt for a deeply buried Cal routine. Fiddling with loss internally is clearly possible (from another rreply), but only
finding the routine would be future proof.
?
Thanks for info about that HP IEEE 488 program. My Win95 machine does still boot up¡??
J Gonna have to find an IEEE488 card though. Or info on what the code drives.
?
Rgds
?
Colin
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]]
On Behalf Of george edmonds via groups.io
Sent: 13 April 2020 00:37
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8920A spectrum analyser amplitude calibration
?
Hi Colin
I have also seen your posting on the HP8924 group which has additional information in it.
First it is very important to say at what frequencies you are experiencing the errors, the main reason for this is that the front panel on a HP8920A gives the operating range as 400KHz to 1GHz. This is ONLY true for the original electromechanical attenuator
version, all the ones that I have seen in the UK have had the PIN diode attenuator fitted which in my experience cannot be trusted below 50MHz. HP claimed 10MHz in their dreams.
Most of these test sets were purchased in the UK for analogue cellular use so the use of a PIN diode attenuator was not an issue.
I would first check to see if the input load measures 50 ohms at the N port, if it does then check and re torque the internal hard line SMA's using a torque spanner, this is very important to avoid damage to the SMA's. There were a number of optimal power handling
input loads available, it is not unknown for excess RF power to damage them.
I have not had to work on a 8920A for some years, but as I recall the calibration/adjustment was carried out via the GPIB port using dedicated HP software that would not run on anything later than Windows 95 or possibly 98.
Hope that this helps
George G6HIG
On Sunday, 12 April 2020, 22:18:40 BST, Colin Smithers <colin@...> wrote:
Hi all,
I have an 8920A and the spectrum analyser amplitude level is 3dB out. I have read enough to understand that calibrating this is a bit of a secret. Does anyone know it please?
Similarly for calibrating the power meter.
I have asked the same question on the 8924-series group.
Kind regards
Colin Smithers G4CWH
|
Re: Opens and shorts for 4285A LCR meter owners
Hi David.
?
Where did you get the BNC connectors for your open and short?
Were they taken from test fixtures or can they be purchased separately?
Thanks!
You can get them on eBay. Search for BNC levers or BNC handles. One does need to cut some BNC plugs up to make these, as you only want the inner part of the plug. I use a grinder and hacksaw.?
HP do make some fixtures with 4 levers, and some with none. Two is a compromise.
I want to make a fixture that allows one to apply a DC offset of up to 30 kV. That will be a challenge. I will probably restrict its use to a lower specification LCR meter I have, as I wrote not want to risk damaging these. At 30 kV, some precautions will be necessary.? -- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@...Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
|
Re: Bill West keytop puller
On Sun, Apr 12, 2020 at 02:05 PM, Maurice Smulders wrote:
What is the safest way to pull the keytops of a Bill West keyboard? I have a 3325A and 8131A with sticky keys I want to fix...
AT https://www.youtube.com/watch?v=kYV7oWQTfVI From 3:10 to 5:08... Curious Mark pulls the caps off a 3325A Bill West keyboard... and shows cleaning and lubing (with DeoxiT... which I think, DeoxiT is mostly bunkum). There is a shot of the tool he is using (looks like a small nail puller) at exactly 4.03/15:18. Seems a bit brutal... He tore the plunger out of the 7 key's frame! (...you can see that if you watch closely.) If you look in the comments you'll see? Raymond Domp Frank's? recommendations (...same as he has posted in this thread.) Best regards and wishes. Roy
|
Re: GPSDO connected to external ref inputs
Thanks, Bruce and Lou.
I figured as long as the units were powered up everything should be OK.? Just paranoid I guess.
Jim
Sent from my Verizon, Samsung Galaxy smartphone
toggle quoted message
Show quoted text
-------- Original message -------- From: Lou Blasco <vk3alb@...> Date: 4/12/20 9:02 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] GPSDO connected to external ref inputs
Agree with Bruce, Been running my 10 MHz 24x7 into a HP-5342A, HP-8901B and Fluke 6060A/AN for years with no ill effects. Regards Lou VK3ALB
|
Re: GPSDO connected to external ref inputs
Agree with Bruce,
Been running my 10 MHz 24x7 into a HP-5342A, HP-8901B and Fluke 6060A/AN for years with no ill effects.
Regards
Lou
VK3ALB
|
Re: Opens and shorts for 4285A LCR meter owners
Hi David.
?
Where did you get the BNC connectors for your open and short?
Were they taken from test fixtures or can they be purchased separately?
Thanks!
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Re: GPSDO connected to external ref inputs
I've had a lab" with several 8566s, two 8510c,and (probably) 5 5345As + numerous HP equipment with the distributio amp feeding everything all the time. Don't believe my amp puts out quite 4v (think it is more like 1.5 - 2.0, but I've never had a problem.
Quoting Jim Ford <james.ford@...>:
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Hi, everybody.
I keep my (Leo Bodnar) GPS-disciplined oscillator running continuously, and I have its output going to a BG7TBL distribution amp (yes, I could have designed and built my own distribution amp easily, but for <$100, it's not worth the time, since I'm not retired yet) . So far, the only instruments I own that can use the 10 MHz from the GPSDO are an 8566A spectrum analyzer and a 5343A frequency counter. Now the distribution amp puts out 4 Vp-p unterminated and 2 Vp-p = +10 dBm into 50 ohms, and I'm wondering if I should keep the outputs of the distrib amp running continuously into the spec an and freq counter.
Maybe I'm just extra cautious, but ISTR blowing something up early in my career by putting hot signals into something not powered up. I keep the 8566A and 5343A powered up and in Standby mode at all times. Perhaps we have the designers of said HP equipments in the group? Or at least somebody familiar with the innards of one and/or the other piece of gear. Magnificent stuff, BTW!
Thanks.
Jim Ford
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Re: Are HP3325 A and B version parts interchangeable?
BTW, there are a few possibilities to explain instability of the output amplitude. One of the causes is worn out relays even with the newer Aromat relays. I ended up building a daughterboard using currently available Omron relays to replace the obsolete Aromat brand.
Other causes for instability are bad grounds and lossy coaxial cables downstream of the relays. Bad ribbon cables between the A21/A03/A14 and controller boards is another common cause. This is caused by high resistance contacts within the ribbon cable crimps. I have resorted to building my own replacement ribbon cables because the original cables are no longer manufactured. When replacing a ribbon cable, it is usually necessary to realign the 3325A/B because it is almost always too high on the DC Offset and function pp voltages
Joe
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WTB: 3467A Printer module.
I have a 3567A Logging Multimeter here that I picked up cheap but it is missing the printer module.
Does anyone have a printer module they are willing to sell and send to Japan?
?
Thanks!
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Re: Are HP3325 A and B version parts interchangeable?
Hi Ed,
I work on restoring both models and have run into these issue on occasion. The controller board, power supply, and front panel/display are not interchangeable between the A&B models, but the A3, A14, A21, and attenuator boards are interchangeable. Be careful not to use older revision boards in the B model (i.e. A14C, A21D, and A3C should be the only boards used in the B model). Additionally, both 001 and 002 options are interchangeable. Theoretically, the older Ovenaire OCXO used in the A model should work in the B Model, but newer the Nihon Dempa assemblies are more stable and warm up quicker.
IIRC, one of the service notes addresses older versions of A04 / A14 being applied to newer units due to a possibility of catching fire.
Regards,
Joe, KN5U
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Hi, everybody.
I'm looking for a?85660-20101, the piece of hardline or semi-rigid coax that connects the IF input to the IF output on the front of the synthesizer section of an 8566A spectrum analyzer.? I can't find it on eBay.
My 8566A came with a piece of semi-flexible cable, so it works, but I keep bumping it because it's right about at knee level (I keep that 112 lb monster on the bottom shelf of my bench to keep the center of gravity low).? Sure would be nice to have the real thing!? Anybody have a parts mule that could spare an?85660-20101?
I'm in Southern California, USA.
Thanks.
Jim Ford
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David C. Partridge
Jared Cabot
Dr. David Kirkby, Kirkby Microwave Ltd