Re: N5230A Network analyzer power supply
What a helpful message, dear Caesar; thank you so much!
I only replaced the 33uF/25V with a 33uF/50V. The 47uF/50V is OK. It's not necessary to solder out the small vertical board. I only removed the two large rectifier caps to have enough space for repair.
Best regards
Hansjoerg HB9EWH
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Re: HP YIG replacement 3-7GHz
may be some forum ?member lives in HK and could check (?)
adri
?
?
?
?
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Show quoted text
----- Messaggio originale -----
Inviato: 23/03/2022 12:05:48
Oggetto: Re: [HP-Agilent-Keysight-equipment] HP YIG replacement 3-7GHz
problem is most of those brokers do actually not have them they Scam you in sending money
best regards Peter
just for infomation : it looks like Micro-Semiconductor.com from HK have a stock of 5621 of Avago AT-42000-GP4 available
Might be the device we are talking about in a different packaging (?)
adri
?
?
?
----- Messaggio originale -----
Inviato: 22/03/2022 19:11:42
Oggetto: Re: [HP-Agilent-Keysight-equipment] HP YIG replacement 3-7GHz
Hello Lothar the device is AT41000 or AT42000 of course obsolete. I am sure if we could find a reliable source it maybe would get CT1DMK to use his bonder for repairs again. I know he is out of parts but has repaired them in the past.
I love impossible challenges. People always told me the Rythm tower from HP8563E would be impossible to adjust. But none of the less I can do that on daily basis if needed. It was a long road but now possible. In this case a Scalar netwoek analyzers 26.5Ghz comes in handy as the detektor is broadband so i look at the downconverted IF signal. I use that for adjustments at all frequencies
73 Peter OZ1LPR
The first challenge is to figure out the transistor they used , HP had their own foundry and not all parts they made were sold as products on the open market.
Given the frequency range of the yig it was likely to be a HBT rather than a GaAs Fet but HP semiconductor became Avago and then broadcom and to my knowledge they don’t sell die level parts!
The next challenge then is to remove the old transistor and mount a new one, usually devices are mounted using eutectic solder preforms , the stage is heated until the solder melts and the part is then “scrubbed “ in as gold from the back metalization diffuses into the solder the melting point increases and the solder solidifies , in order to remove the part you would have to heat up the solder past the new melting point without imposing thermal stress on the other parts used or dislocating them !
To mount a new part you need a die attach as well as preforms, you could of course use conductive epoxy but the heat transfer generally is not as good as with eutectic die attach so you might run into issues with reliability!
As far as wirebonders concerns there are plenty on ebay , expect to pay between $5000 and $16000 for a refurbished one , for this type of work you need a wedge/wire bonder , if you plan on rebuilding modules plan on getting a deep access bonder or a convertible machine that can be used for different processes .
The biggest challenge with bonding is to figure out the right settings though, usually in a production environment the supplier of the semiconductor devices used provides bond samples which in essence are parts that are not working ok those samples are then bonded in a dummy circuit and a pull tester is used to check the strength of the bond?
Also make sure you have someone with a steady hand and young eyes to threat the bonder ? and also invest in a vibration isolation table or platform to set your bonder on?
On Mar 22, 2022, at 02:28, Peter Hansen via groups.io <oz1lpr@...> wrote:
?
I have succeded to integrate a YO84 YIG faily simple and you can use +/-15 for 30V for heater it is ok and shunting the Sense resistors in the Maincoil driver means it can span the 3-7Ghz. I have made changes to the Loop so it is yield low Phase noise. Output from the YIG it self is good also. Mechanical implementation is done by using the original mechanic shell and make a hole for the YIG. It can be jammed in there when I mount the YIG in the unit. A PCB "still prototype" is mounted with a 10pin pinheader so the orignal cable can be used. BUT BUT now the challenge. The original YIG does not get hot due to the sensitve coils meaning less drift. If the Loop is opened by placing the jumper in the TEST position I observe a drift of the YIG of around 5Mhz from cold to warm. The Avantek YIG drift around 30-40Mhz. The Loop is build to compensate for 10Mhz drift. This means you can either have a unlock condition ERR301 during warm up or you will get it during use.
Playing around in the Loop is not a things for the average guy to do. The Frequency Lock? circuit is quite hard to work with. Changes to the loop will also challenge your phasenoise performance. I am sure this is why HP deviated from the standard sensitivity on the maincoil to keep drift down. The avantek YIG gets hot the HP ones do not.
More fruitfull would be to find a replacement for the Bonded Transistor and get someone with a Wirebonder to service them.
I do currently not have a wirebonder but as I am repairing alot of advanced HP equipment I am considering it. But where to source components for tryouts.
best regards Peter OZ1LPR
Hi Peter, Et al,
Sorry for the delayed response to all the positive comments. I have been away camping, soaking up what is left of the good weather in autumn, trying my new HF radio set up.
No doubt, there will be many challenges ahead, but I am determined to find a solution. I am waiting on a mail from Micro Lambda to see if they have ever made a replacement, the chap is going to ask the question for me, they have been so helpful to date. There are other Micro Lambda models to suit Tek and R&S, so they have made replacement models for branded SA and Sign Gens. No harm asking.?
Peter, I think the original HP data sheet is right, this does represent a challenge at? or around 40MHz/mA, the hardware and software is tightly integrated, thus a YIG with similar spec or the development of an interface driver is needed. I haven't thought that far ahead yet.
Like yourself, and I am sure others on the forum have purchased a YIG in the past to adapt, I purchased a Avantek Y084-1215 about 10 years ago, I recently tried to adapt via a crude interface driver, but this did not work out to well. Although the Avantek YIG works extremely well for it's vintage, it's main coil spec is way out at ~22.4 MHZ/mA. In addition, getting the juice to run the heater from an internal supply is a challenge.
I am prepared to lay out the cash up to a point to develop a solution.
I hope I do not have to eat my words in time.
Stay tuned.
Regards
Gerald
VK3GM
?
|
Re: HP YIG replacement 3-7GHz
problem is most of those brokers do actually not have them they Scam you in sending money
best regards Peter
just for infomation : it looks like Micro-Semiconductor.com from HK have a stock of 5621 of Avago AT-42000-GP4 available
Might be the device we are talking about in a different packaging (?)
adri
?
?
?
toggle quoted message
Show quoted text
----- Messaggio originale -----
Inviato: 22/03/2022 19:11:42
Oggetto: Re: [HP-Agilent-Keysight-equipment] HP YIG replacement 3-7GHz
Hello Lothar the device is AT41000 or AT42000 of course obsolete. I am sure if we could find a reliable source it maybe would get CT1DMK to use his bonder for repairs again. I know he is out of parts but has repaired them in the past.
I love impossible challenges. People always told me the Rythm tower from HP8563E would be impossible to adjust. But none of the less I can do that on daily basis if needed. It was a long road but now possible. In this case a Scalar netwoek analyzers 26.5Ghz
comes in handy as the detektor is broadband so i look at the downconverted IF signal. I use that for adjustments at all frequencies
73 Peter OZ1LPR
The first challenge is to figure out the transistor they used , HP had their own foundry and not all parts they made were sold as products on the open market.
Given the frequency range of the yig it was likely to be a HBT rather than a GaAs Fet but HP semiconductor became Avago and then broadcom and to my knowledge they don’t sell die level parts!
The next challenge then is to remove the old transistor and mount a new one, usually devices are mounted using eutectic solder preforms , the stage is heated until the solder melts and the part is then “scrubbed “ in as gold from the back metalization
diffuses into the solder the melting point increases and the solder solidifies , in order to remove the part you would have to heat up the solder past the new melting point without imposing thermal stress on the other parts used or dislocating them !
To mount a new part you need a die attach as well as preforms, you could of course use conductive epoxy but the heat transfer generally is not as good as with eutectic die attach so you might run into issues with reliability!
As far as wirebonders concerns there are plenty on ebay , expect to pay between $5000 and $16000 for a refurbished one , for this type of work you need a wedge/wire bonder , if you plan on rebuilding modules plan on getting a deep access bonder or a convertible
machine that can be used for different processes .
The biggest challenge with bonding is to figure out the right settings though, usually in a production environment the supplier of the semiconductor devices used provides bond samples which in essence are parts that are not working ok those samples are
then bonded in a dummy circuit and a pull tester is used to check the strength of the bond?
Also make sure you have someone with a steady hand and young eyes to threat the bonder ? and also invest in a vibration isolation table or platform to set your bonder on?
On Mar 22, 2022, at 02:28, Peter Hansen via groups.io <oz1lpr@...> wrote:
?
I have succeded to integrate a YO84 YIG faily simple and you can use +/-15 for 30V for heater it is ok and shunting the Sense resistors in the Maincoil driver means it can span the 3-7Ghz. I have made changes to the Loop so it is yield low Phase noise. Output
from the YIG it self is good also. Mechanical implementation is done by using the original mechanic shell and make a hole for the YIG. It can be jammed in there when I mount the YIG in the unit. A PCB "still prototype" is mounted with a 10pin pinheader so
the orignal cable can be used. BUT BUT now the challenge. The original YIG does not get hot due to the sensitve coils meaning less drift. If the Loop is opened by placing the jumper in the TEST position I observe a drift of the YIG of around 5Mhz from cold
to warm. The Avantek YIG drift around 30-40Mhz. The Loop is build to compensate for 10Mhz drift. This means you can either have a unlock condition ERR301 during warm up or you will get it during use.
Playing around in the Loop is not a things for the average guy to do. The Frequency Lock? circuit is quite hard to work with. Changes to the loop will also challenge your phasenoise performance. I am sure this is why HP deviated from the standard sensitivity
on the maincoil to keep drift down. The avantek YIG gets hot the HP ones do not.
More fruitfull would be to find a replacement for the Bonded Transistor and get someone with a Wirebonder to service them.
I do currently not have a wirebonder but as I am repairing alot of advanced HP equipment I am considering it. But where to source components for tryouts.
best regards Peter OZ1LPR
Hi Peter, Et al,
Sorry for the delayed response to all the positive comments. I have been away camping, soaking up what is left of the good weather in autumn, trying my new HF radio set up.
No doubt, there will be many challenges ahead, but I am determined to find a solution. I am waiting on a mail from Micro Lambda to see if they have ever made a replacement, the chap is going to ask the question for me, they have been so helpful to date. There
are other Micro Lambda models to suit Tek and R&S, so they have made replacement models for branded SA and Sign Gens. No harm asking.?
Peter, I think the original HP data sheet is right, this does represent a challenge at? or around 40MHz/mA, the hardware and software is tightly integrated, thus a YIG with similar spec or the development of an interface driver is needed. I haven't thought
that far ahead yet.
Like yourself, and I am sure others on the forum have purchased a YIG in the past to adapt, I purchased a Avantek Y084-1215 about 10 years ago, I recently tried to adapt via a crude interface driver, but this did not work out to well. Although the Avantek YIG
works extremely well for it's vintage, it's main coil spec is way out at ~22.4 MHZ/mA. In addition, getting the juice to run the heater from an internal supply is a challenge.
I am prepared to lay out the cash up to a point to develop a solution.
I hope I do not have to eat my words in time.
Stay tuned.
Regards
Gerald
VK3GM
?
|
Re: HP YIG replacement 3-7GHz
just for infomation : it looks like Micro-Semiconductor.com from HK have a stock of 5621 of Avago AT-42000-GP4 available
Might be the device we are talking about in a different packaging (?)
adri
?
?
?
toggle quoted message
Show quoted text
----- Messaggio originale -----
Inviato: 22/03/2022 19:11:42
Oggetto: Re: [HP-Agilent-Keysight-equipment] HP YIG replacement 3-7GHz
Hello Lothar the device is AT41000 or AT42000 of course obsolete. I am sure if we could find a reliable source it maybe would get CT1DMK to use his bonder for repairs again. I know he is out of parts but has repaired them in the past.
I love impossible challenges. People always told me the Rythm tower from HP8563E would be impossible to adjust. But none of the less I can do that on daily basis if needed. It was a long road but now possible. In this case a Scalar netwoek analyzers 26.5Ghz comes in handy as the detektor is broadband so i look at the downconverted IF signal. I use that for adjustments at all frequencies
73 Peter OZ1LPR
The first challenge is to figure out the transistor they used , HP had their own foundry and not all parts they made were sold as products on the open market.
Given the frequency range of the yig it was likely to be a HBT rather than a GaAs Fet but HP semiconductor became Avago and then broadcom and to my knowledge they don’t sell die level parts!
The next challenge then is to remove the old transistor and mount a new one, usually devices are mounted using eutectic solder preforms , the stage is heated until the solder melts and the part is then “scrubbed “ in as gold from the back metalization diffuses into the solder the melting point increases and the solder solidifies , in order to remove the part you would have to heat up the solder past the new melting point without imposing thermal stress on the other parts used or dislocating them !
To mount a new part you need a die attach as well as preforms, you could of course use conductive epoxy but the heat transfer generally is not as good as with eutectic die attach so you might run into issues with reliability!
As far as wirebonders concerns there are plenty on ebay , expect to pay between $5000 and $16000 for a refurbished one , for this type of work you need a wedge/wire bonder , if you plan on rebuilding modules plan on getting a deep access bonder or a convertible machine that can be used for different processes .
The biggest challenge with bonding is to figure out the right settings though, usually in a production environment the supplier of the semiconductor devices used provides bond samples which in essence are parts that are not working ok those samples are then bonded in a dummy circuit and a pull tester is used to check the strength of the bond?
Also make sure you have someone with a steady hand and young eyes to threat the bonder ? and also invest in a vibration isolation table or platform to set your bonder on?
On Mar 22, 2022, at 02:28, Peter Hansen via groups.io <oz1lpr@...> wrote:
?
I have succeded to integrate a YO84 YIG faily simple and you can use +/-15 for 30V for heater it is ok and shunting the Sense resistors in the Maincoil driver means it can span the 3-7Ghz. I have made changes to the Loop so it is yield low Phase noise. Output from the YIG it self is good also. Mechanical implementation is done by using the original mechanic shell and make a hole for the YIG. It can be jammed in there when I mount the YIG in the unit. A PCB "still prototype" is mounted with a 10pin pinheader so the orignal cable can be used. BUT BUT now the challenge. The original YIG does not get hot due to the sensitve coils meaning less drift. If the Loop is opened by placing the jumper in the TEST position I observe a drift of the YIG of around 5Mhz from cold to warm. The Avantek YIG drift around 30-40Mhz. The Loop is build to compensate for 10Mhz drift. This means you can either have a unlock condition ERR301 during warm up or you will get it during use.
Playing around in the Loop is not a things for the average guy to do. The Frequency Lock? circuit is quite hard to work with. Changes to the loop will also challenge your phasenoise performance. I am sure this is why HP deviated from the standard sensitivity on the maincoil to keep drift down. The avantek YIG gets hot the HP ones do not.
More fruitfull would be to find a replacement for the Bonded Transistor and get someone with a Wirebonder to service them.
I do currently not have a wirebonder but as I am repairing alot of advanced HP equipment I am considering it. But where to source components for tryouts.
best regards Peter OZ1LPR
Hi Peter, Et al,
Sorry for the delayed response to all the positive comments. I have been away camping, soaking up what is left of the good weather in autumn, trying my new HF radio set up.
No doubt, there will be many challenges ahead, but I am determined to find a solution. I am waiting on a mail from Micro Lambda to see if they have ever made a replacement, the chap is going to ask the question for me, they have been so helpful to date. There are other Micro Lambda models to suit Tek and R&S, so they have made replacement models for branded SA and Sign Gens. No harm asking.?
Peter, I think the original HP data sheet is right, this does represent a challenge at? or around 40MHz/mA, the hardware and software is tightly integrated, thus a YIG with similar spec or the development of an interface driver is needed. I haven't thought that far ahead yet.
Like yourself, and I am sure others on the forum have purchased a YIG in the past to adapt, I purchased a Avantek Y084-1215 about 10 years ago, I recently tried to adapt via a crude interface driver, but this did not work out to well. Although the Avantek YIG works extremely well for it's vintage, it's main coil spec is way out at ~22.4 MHZ/mA. In addition, getting the juice to run the heater from an internal supply is a challenge.
I am prepared to lay out the cash up to a point to develop a solution.
I hope I do not have to eat my words in time.
Stay tuned.
Regards
Gerald
VK3GM
?
|
Re: HP 180 series scope CRTs
Thanks for the references- may not be an option for an analog scope but I do have a 141 mainframe that could use it! ?Cheers DaveB, NZ ?
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From: [email protected] [mailto:[email protected]] On Behalf Of green
Sent: Wednesday, March 23, 2022 09:24
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 180 series scope CRTs ?
Perhaps you might be able to "shoehorn in" an LCD module to replace the CRT in the HP 182 ?
There was a Blog showing this done for the HP 141 SA, likely different, but provides an idea:
LCD module for the HP 141:
|
Re: HP 180 series scope CRTs
The CRT was left over from a 180A that was broken down for parts some time
back- mainframe is long gone.
This 182 was being used for its large screen with std plugins, not as a
spec an.
Somewhat of a nuisance to have to plow thru schematics to get some idea of
CRT data but Looks like I may have to.
DaveB, NZ
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-----Original Message----- From: [email protected][mailto: [email protected]] On Behalf Of Paul Bicknell Sent: Tuesday, March 22, 2022 11:47 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] HP 180 series scope CRTs Hi Dave From memory the 180 EHT is lower than that used on the 182 Why don't you just use a 180 main frame thy take all the same plugins The 181 has storage and is better for use as a spectrum analyser As you have noted the 182 had a 2 tubes There is a CRT x ref in the files on this site The CRT electrical connections and voltages will be in the relevant service manuals 180, 182C , 182T Regards Paul -----Original Message----- From: [email protected][mailto: [email protected]] On Behalf Of Dave Brown Sent: 21 March 2022 22:22 To: [email protected]Subject: [HP-Agilent-Keysight-equipment] HP 180 series scope CRTs I have a 182T that needs a new CRT. Wondering how similar the electrical specs of the CRTs are in the 180 series as I have a good CRT from an old 180A that (aside from the obvious mechanical aspects) might be able to be pressed into service. The 182T uses a 5083-3970 and the 180A has a 5083-0952. The 182A uses a 5083-2852 and the 182C uses a 5083- 3952. So the question is - apart from screen sizes and phosphor differences, how similar-or otherwise- are all these jugs? Is there a source of electrical specs for these CRTs anywhere that could be used for comparison purposes? DaveB, NZ
|
Re: HP 180 series scope CRTs
Spot on Pete- that’s exactly what the scope is used - with - ?std plugins- that large screen is great but any screen would be better than no screen! DaveB, NZ ?
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From: [email protected] [mailto:[email protected]] On Behalf Of saipan59 (Pete)
Sent: Tuesday, March 22, 2022 11:41
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 180 series scope CRTs ? I'm thinking that the 182T is primarily used with a spec-an plug-in, and therefore has a long-presistence phosphor.
Seems like a 'regular' CRT would not be a good choice, unless you're only going to use it with scope plugins.
Pete
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Re: Agilent 3458A Troubleshooting
George,
I'm in a similar situation - I have 4 34401A's and the 3458A and it would be nice if they all agreed! One source that looks promising is from the author of that link:
Out of stock at the moment but he tells me they will be available again in a couple of months.
Keith
|
Re: Agilent 3458A Troubleshooting
Thank you for the info about the AD584 voltage ref. I am not surprised – if something looks too good to be true, it usually has some hidden warts. ? I am looking for long term stability in the 3458A, not absolute accuracy. I want to be able to make accurate and repeatable comparison measurements. I have a 3457A as well as a 34401A that was last calibrated two years ago. If I can get the three to perform in the same ballpark I will be happy with the calibration. ? Having said this, if you can suggest a better voltage reference that doesn’t cost the earth, I would be most grateful. ? Unfortunately I can’t make use of the GPIB port until I get the meter going. Once I do, I will certainly investigate the link you have suggested. ? George ?
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Re: Agilent 3458A Troubleshooting
"I do not plan to have this meter calibrated to the point where it is NIST traceable. I want to use it for comparison measurements with repeatable 8.5 digit resolution. I have an HP3245A Universal Source (no longer in cal), and if calibration of the 3458A turns out to be necessary, I will use the 3245A as a voltage reference to calibrate it. I also recently purchased an??on ePay, and I am hoping that it will agree closely with the 3245A."
Those eBay AD584 references - I have one I bought a little while back. It has several issues:
- Absolute accuracy: on the 10V setting is only good to around 2mV
- Temperature sensitivity: The thing seems to have quite a high temp coefficient. Compared to my (Keysight calibrated) HP3458A, of the order of over 10ppm/C .
- Noise: I was surprised to see significant noise spikes on the output, even when disconnected from a charger and running on its internal battery. I've not looked at the circuit closely, but it looks like SMPS noise,
In short they are good enough for checking a 4 1/2 digit DVM, but that's about it.?As for the 3245A, it is certainly better, but it's not really a standard for calibrating a 3458A.
For reading the NVRAMs you might try this:?
It can read the NVRAMs and dump their contents to file via the GPIB.
Keith
|
Re: Agilent 3458A Troubleshooting
Hi Lothar, ? Thank you for the pointer to Keysight. I wasn’t aware of that service. What you have said makes perfect sense. ? Both SERVICE STATUS and SERVICE HISTORY came up “No Results”. ? Keysight have a presence in Victoria, so I rang their support number and explained the problem. The lady I spoke to was most helpful. The reason for no results was probably due to the fact that, because I purchased the unit second hand, it is not registered as belonging to me in their asset register. They are going to fix this and then someone from their service department is going to call be back. I will post the outcome. ? In the meantime, I tried reseating the EPROMs – made no difference. ? Regarding the EPROMs, the neatly printed labels have the Keysight part number printed on them as well as the firmware rev no. This makes me think they were supplied and installed by Keysight. So they should know that this instrument exists. ? Cheers, George G ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Lothar baier
Sent: Wednesday, 23 March 2022 12:47 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent 3458A Troubleshooting? One thing you can do is go on the Keysight website and check the service status, you enter the model and serial number and it tells you when the unit was sold , warranty expiration and when the unit was repaired or calibrated last , if the serial doesn’t check out than the unit is more than likely not legit and you will have problems getting certain parts from Keysight?
On Mar 22, 2022, at 20:43, Lothar baier via groups.io <Lothar@...> wrote: ? There are a few things that don’t make sense , first of the 3458A wasn’t released until 1989 so the 88 serial number doesn’t make sense , in addition Agilent did not enter the picture until 1999 ! Of course it could be that the front panel of the unit at some point sustained some damage and was replaced which would explain the Agilent labeling but the 1988 serial doesn’t make sense unless you got your hands on some pre-production or engineering model that was used internally and never meant to be released to the public in this case you might have a bit of a hard road ahead . ?
On Mar 22, 2022, at 18:51, Labguy via groups.io <georgg@...> wrote: ? Hi Alan, ? I have seen that video before. The meter gives a BEEP and then all green rectangles on the screen plus all the other function below are illuminated, probably as a check to confirm that all the display characters light up. ? 
? Mine doesn’t get past the first rectangle. It just sits there and blinks. ? 
? ? Also, I just noticed that mine has an Agilent front panel, yet the serial number starts with 2823A… indicating a build date of 1988. I think someone has spent significant $$$ on this machine, probably with Agilent, before I acquired it. ? Thank you for the good advice about the ROM and NVRAM chips. I have an EPROM reader/burner (GTek 9000HV) that is supposed to be capable of reading the Dallas chips, and I will get to them in due course. Unfortunately they are not socketed, so they will need to be carefully unsoldered. I will put in high quality sockets if I have to go down this road. ? I will first try resocketing the EPROM chips to see if that helps. If not, I will try reading the EPROM chips in the GTek to see what they contain. They all appear to have new labels with what I think may be Agilent part numbers. One of the labels looks like it may have been lifted in one corner (top right chip, bottom left corner of label is crinkled). Hmmm… ? 
? I don’t make any progress, I will download the binaries for Rev 9, buy a new set of EPROM chips and burn them in. ? Thanks also for the battery issues/calibration blog link. ? I do not plan to have this meter calibrated to the point where it is NIST traceable. I want to use it for comparison measurements with repeatable 8.5 digit resolution. I have an HP3245A Universal Source (no longer in cal), and if calibration of the 3458A turns out to be necessary, I will use the 3245A as a voltage reference to calibrate it. I also recently purchased an ?on ePay, and I am hoping that it will agree closely with the 3245A. ? ? I do most of my lab work with 8753X VNAs. I have several 8753E’s as well as a C and an A, and I use them for a range of testing tasks, including in conjunction with an 8-port HP87050 coax switch and some very expensive BH baluns to test balanced pair data cables and components for clients. I have written a lot of software in FREE PASCAL to drive the GPIB port in order to automate the testing. I use an 82335 ISA GPIB card in an old PC running on DOS. Works like a dream. I have also written GPIB software to drive other HP test equipment. So talking to the 3458A will be no problem, once I get it to wake up! ? Thanks again for all your help Alan. ? Cheers, George ? ? From: [email protected] [mailto:[email protected]] On Behalf Of alan.ambrose@...
Sent: Wednesday, 23 March 2022 1:16 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent 3458A Troubleshooting ? p.s. clip of start-up sequence here:
After lighting up all the display segments it says 'TESTING RAM' and then 'TESTING HARDWARE'. About 4 seconds to first reading.
Alan
|
Re: Question about MMIC amp design for HP 8601a output replacement
Gotta love auto correct
??
?
?
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Show quoted text
From: [email protected] < [email protected]>
On Behalf Of Jim Ford via groups.io
Sent: Tuesday, March 22, 2022 8:08 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
?
Oops, that should be +30 dBm, not +30 damage, of course!? Cursed auto-correct!? LOL!
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/22/22 4:14 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
Going back to school days the term transformer was defined as either a contraption using windings on a iron or ferrite core OR a transmission line transformer using microstrip or
striplines usually in the form of a stepped impedance transformer , usually neither is used in wideband MMIC especially not in the RF range for a variety of reasons including but not limited size and achievable bandwidth !
Wideband MMIC extending into the MHz range or lower are either utilizing feedback elements or are build as distributed amplifiers , the latter can achieve typical bandwidths of
100KHz to 50GHz and output power of 30dBm the only downside is cost as this topology requires a lot of real estate
?
?
Well, Gary did say "without a transformer".? If by transformer we mean a circuit to transform the low output impedance of the amplifier to 50 ohms, then he is correct.? Yes, I have
worked with MMIC amplifiers that run on 5 V that put out greater than +30 damage (=1 watt).
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/22/22 3:12 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
Wrong !
There are several MMICs that can drive 20dBm and higher over the desired frequency range operating below 12V
?
?
My amplifier (as the amplifier by Dasaro Designs) replaces the output hybrid only. The part I used was the BFU590QX, from Digikey.? All three of these amplifiers require 2 stages to replace the output hybrid.
Unlike the Dasaro Designs amplifier, mine is not contained in a shielded enclosure, which allowed me a bit more area. To help remove the heat I have screwed a block of aluminum on the top cover that just contacts the top of the three transistors, with a
thermal pad between the aluminum and transistor case. Not a great solution, but then again we need to draw only about 0.6 watts from each of the two output transistors, about half that from the input transistor. Not a great solution, but it should be adequate
to hold the die temperature down.
+20 dBm is 2.25 Vrms, or 6.32 V peak to peak. You can't get +20 dBm from a +5 V supply without a transformer. A MMIC operating at perhaps less than 12 volts will not be able to provide +20 dBm.
Gary Appel
On 3/22/2022 11:24 AM, DB via groups.io wrote:
Hi Gary,
Thanks for posting your design of the output amp using BFU590Q's.? It looks like the BFU590Q are also becoming hard to obtain as I only saw one supplier had any in stock (BFU590QX only).
I was curious if your design is replacing both the preamp and final output amps inside the A6 module or just the final output amp.? On my 8601, It appears that both of the modules have an issue,so hoping that a cascade set of 2 or 3 MMIC's might work.? I have
a good signal level input into the A6 module.
Thanks,
DB
|
Re: Agilent 3458A Troubleshooting
One thing you can do is go on the Keysight website and check the service status, you enter the model and serial number and it tells you when the unit was sold , warranty expiration and when the unit was repaired or calibrated last , if the serial doesn’t check
out than the unit is more than likely not legit and you will have problems getting certain parts from Keysight?
toggle quoted message
Show quoted text
On Mar 22, 2022, at 20:43, Lothar baier via groups.io <Lothar@...> wrote:
? There are a few things that don’t make sense , first of the 3458A wasn’t released until 1989 so the 88 serial number doesn’t make sense , in addition Agilent did not enter the picture until 1999 !
Of course it could be that the front panel of the unit at some point sustained some damage and was replaced which would explain the Agilent labeling but the 1988 serial doesn’t make sense unless you got your hands on some pre-production or engineering
model that was used internally and never meant to be released to the public in this case you might have a bit of a hard road ahead .
On Mar 22, 2022, at 18:51, Labguy via groups.io <georgg@...> wrote:
?
Hi Alan,
?
I have seen that video before. The meter gives a BEEP and then all green rectangles on the screen plus all the other function below are illuminated, probably as a check to confirm
that all the display characters light up.
?
?
Mine doesn’t get past the first rectangle. It just sits there and blinks.
?
?
?
Also, I just noticed that mine has an Agilent front panel, yet the serial number starts with 2823A… indicating a build date of 1988. I think someone has spent significant $$$
on this machine, probably with Agilent, before I acquired it.
?
Thank you for the good advice about the ROM and NVRAM chips. I have an EPROM reader/burner (GTek 9000HV) that is supposed to be capable of reading the Dallas chips, and I will
get to them in due course. Unfortunately they are not socketed, so they will need to be carefully unsoldered. I will put in high quality sockets if I have to go down this road.
?
I will first try resocketing the EPROM chips to see if that helps. If not, I will try reading the EPROM chips in the GTek to see what they contain. They all appear to have new
labels with what I think may be Agilent part numbers. One of the labels looks like it may have been lifted in one corner (top right chip, bottom left corner of label is crinkled). Hmmm…
?
?
I don’t make any progress, I will download the binaries for Rev 9, buy a new set of EPROM chips and burn them in.
?
Thanks also for the battery issues/calibration blog link.
?
I do not plan to have this meter calibrated to the point where it is NIST traceable. I want to use it for comparison measurements with repeatable 8.5 digit resolution. I have
an HP3245A Universal Source (no longer in cal), and if calibration of the 3458A turns out to be necessary, I will use the 3245A as a voltage reference to calibrate it. I also recently purchased an
?on ePay, and I am hoping that it will agree closely with the 3245A.
?
?
I do most of my lab work with 8753X VNAs. I have several 8753E’s as well as a C and an A, and I use them for a range of testing tasks, including in conjunction with an 8-port
HP87050 coax switch and some very expensive BH baluns to test balanced pair data cables and components for clients. I have written a lot of software in FREE PASCAL to drive the GPIB port in order to automate the testing. I use an 82335 ISA GPIB card in an
old PC running on DOS. Works like a dream. I have also written GPIB software to drive other HP test equipment. So talking to the 3458A will be no problem, once I get it to wake up!
?
Thanks again for all your help Alan.
?
Cheers,
George
?
?
From: [email protected] [mailto:[email protected]]
On Behalf Of alan.ambrose@...
Sent: Wednesday, 23 March 2022 1:16 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent 3458A Troubleshooting
?
p.s. clip of start-up sequence here:
After lighting up all the display segments it says 'TESTING RAM' and then 'TESTING HARDWARE'. About 4 seconds to first reading.
Alan
|
Re: Agilent 3458A Troubleshooting
There are a few things that don’t make sense , first of the 3458A wasn’t released until 1989 so the 88 serial number doesn’t make sense , in addition Agilent did not enter the picture until 1999 !
Of course it could be that the front panel of the unit at some point sustained some damage and was replaced which would explain the Agilent labeling but the 1988 serial doesn’t make sense unless you got your hands on some pre-production or engineering
model that was used internally and never meant to be released to the public in this case you might have a bit of a hard road ahead .
toggle quoted message
Show quoted text
On Mar 22, 2022, at 18:51, Labguy via groups.io <georgg@...> wrote:
?
Hi Alan,
?
I have seen that video before. The meter gives a BEEP and then all green rectangles on the screen plus all the other function below are illuminated, probably as a check to confirm
that all the display characters light up.
?
?
Mine doesn’t get past the first rectangle. It just sits there and blinks.
?
?
?
Also, I just noticed that mine has an Agilent front panel, yet the serial number starts with 2823A… indicating a build date of 1988. I think someone has spent significant $$$
on this machine, probably with Agilent, before I acquired it.
?
Thank you for the good advice about the ROM and NVRAM chips. I have an EPROM reader/burner (GTek 9000HV) that is supposed to be capable of reading the Dallas chips, and I will
get to them in due course. Unfortunately they are not socketed, so they will need to be carefully unsoldered. I will put in high quality sockets if I have to go down this road.
?
I will first try resocketing the EPROM chips to see if that helps. If not, I will try reading the EPROM chips in the GTek to see what they contain. They all appear to have new
labels with what I think may be Agilent part numbers. One of the labels looks like it may have been lifted in one corner (top right chip, bottom left corner of label is crinkled). Hmmm…
?
?
I don’t make any progress, I will download the binaries for Rev 9, buy a new set of EPROM chips and burn them in.
?
Thanks also for the battery issues/calibration blog link.
?
I do not plan to have this meter calibrated to the point where it is NIST traceable. I want to use it for comparison measurements with repeatable 8.5 digit resolution. I have
an HP3245A Universal Source (no longer in cal), and if calibration of the 3458A turns out to be necessary, I will use the 3245A as a voltage reference to calibrate it. I also recently purchased an
?on ePay, and I am hoping that it will agree closely with the 3245A.
?
?
I do most of my lab work with 8753X VNAs. I have several 8753E’s as well as a C and an A, and I use them for a range of testing tasks, including in conjunction with an 8-port
HP87050 coax switch and some very expensive BH baluns to test balanced pair data cables and components for clients. I have written a lot of software in FREE PASCAL to drive the GPIB port in order to automate the testing. I use an 82335 ISA GPIB card in an
old PC running on DOS. Works like a dream. I have also written GPIB software to drive other HP test equipment. So talking to the 3458A will be no problem, once I get it to wake up!
?
Thanks again for all your help Alan.
?
Cheers,
George
?
?
From: [email protected] [mailto:[email protected]]
On Behalf Of alan.ambrose@...
Sent: Wednesday, 23 March 2022 1:16 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent 3458A Troubleshooting
?
p.s. clip of start-up sequence here:
After lighting up all the display segments it says 'TESTING RAM' and then 'TESTING HARDWARE'. About 4 seconds to first reading.
Alan
|
Re: Question about MMIC amp design for HP 8601a output replacement
Oops, that should be +30 dBm, not +30 damage, of course!? Cursed auto-correct!? LOL!
Jim
Sent from my T-Mobile 4G LTE Device
toggle quoted message
Show quoted text
-------- Original message -------- From: Lothar baier <Lothar@...> Date: 3/22/22 4:14 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
Going back to school days the term transformer was defined as either a contraption using windings on a iron or ferrite core OR a transmission line transformer using microstrip or striplines usually in the form of a stepped impedance transformer
, usually neither is used in wideband MMIC especially not in the RF range for a variety of reasons including but not limited size and achievable bandwidth !
Wideband MMIC extending into the MHz range or lower are either utilizing feedback elements or are build as distributed amplifiers , the latter can achieve typical bandwidths of 100KHz to 50GHz and output power of 30dBm the only downside
is cost as this topology requires a lot of real estate
?
?
Well, Gary did say "without a transformer".? If by transformer we mean a circuit to transform the low output impedance of the amplifier to 50 ohms, then he is correct.? Yes, I have worked with MMIC amplifiers that run on 5 V that put out
greater than +30 damage (=1 watt).
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/22/22 3:12 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
Wrong !
There are several MMICs that can drive 20dBm and higher over the desired frequency range operating below 12V
?
?
My amplifier (as the amplifier by Dasaro Designs) replaces the output hybrid only. The part I used was the BFU590QX, from Digikey.? All three of these amplifiers require 2 stages to replace the output hybrid.
Unlike the Dasaro Designs amplifier, mine is not contained in a shielded enclosure, which allowed me a bit more area. To help remove the heat I have screwed a block of aluminum on the top cover that just contacts the top of the three transistors, with a
thermal pad between the aluminum and transistor case. Not a great solution, but then again we need to draw only about 0.6 watts from each of the two output transistors, about half that from the input transistor. Not a great solution, but it should be adequate
to hold the die temperature down.
+20 dBm is 2.25 Vrms, or 6.32 V peak to peak. You can't get +20 dBm from a +5 V supply without a transformer. A MMIC operating at perhaps less than 12 volts will not be able to provide +20 dBm.
Gary Appel
On 3/22/2022 11:24 AM, DB via groups.io wrote:
Hi Gary,
Thanks for posting your design of the output amp using BFU590Q's.? It looks like the BFU590Q are also becoming hard to obtain as I only saw one supplier had any in stock (BFU590QX only).
I was curious if your design is replacing both the preamp and final output amps inside the A6 module or just the final output amp.? On my 8601, It appears that both of the modules have an issue,so hoping that a cascade set of 2 or 3 MMIC's might work.? I have
a good signal level input into the A6 module.
Thanks,
DB
|
Re: Agilent 3458A Troubleshooting
Hi Alan, ? I have seen that video before. The meter gives a BEEP and then all green rectangles on the screen plus all the other function below are illuminated, probably as a check to confirm that all the display characters light up. ? 
? Mine doesn’t get past the first rectangle. It just sits there and blinks. ? 
? ? Also, I just noticed that mine has an Agilent front panel, yet the serial number starts with 2823A… indicating a build date of 1988. I think someone has spent significant $$$ on this machine, probably with Agilent, before I acquired it. ? Thank you for the good advice about the ROM and NVRAM chips. I have an EPROM reader/burner (GTek 9000HV) that is supposed to be capable of reading the Dallas chips, and I will get to them in due course. Unfortunately they are not socketed, so they will need to be carefully unsoldered. I will put in high quality sockets if I have to go down this road. ? I will first try resocketing the EPROM chips to see if that helps. If not, I will try reading the EPROM chips in the GTek to see what they contain. They all appear to have new labels with what I think may be Agilent part numbers. One of the labels looks like it may have been lifted in one corner (top right chip, bottom left corner of label is crinkled). Hmmm… ? 
? I don’t make any progress, I will download the binaries for Rev 9, buy a new set of EPROM chips and burn them in. ? Thanks also for the battery issues/calibration blog link. ? I do not plan to have this meter calibrated to the point where it is NIST traceable. I want to use it for comparison measurements with repeatable 8.5 digit resolution. I have an HP3245A Universal Source (no longer in cal), and if calibration of the 3458A turns out to be necessary, I will use the 3245A as a voltage reference to calibrate it. I also recently purchased an ?on ePay, and I am hoping that it will agree closely with the 3245A. ? ? I do most of my lab work with 8753X VNAs. I have several 8753E’s as well as a C and an A, and I use them for a range of testing tasks, including in conjunction with an 8-port HP87050 coax switch and some very expensive BH baluns to test balanced pair data cables and components for clients. I have written a lot of software in FREE PASCAL to drive the GPIB port in order to automate the testing. I use an 82335 ISA GPIB card in an old PC running on DOS. Works like a dream. I have also written GPIB software to drive other HP test equipment. So talking to the 3458A will be no problem, once I get it to wake up! ? Thanks again for all your help Alan. ? Cheers, George ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of alan.ambrose@...
Sent: Wednesday, 23 March 2022 1:16 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Agilent 3458A Troubleshooting ? p.s. clip of start-up sequence here:
After lighting up all the display segments it says 'TESTING RAM' and then 'TESTING HARDWARE'. About 4 seconds to first reading.
Alan
|
Re: Question about MMIC amp design for HP 8601a output replacement
Going back to school days the term transformer was defined as either a contraption using windings on a iron or ferrite core OR a transmission line transformer using microstrip or striplines usually in the form of a stepped impedance transformer
, usually neither is used in wideband MMIC especially not in the RF range for a variety of reasons including but not limited size and achievable bandwidth !
Wideband MMIC extending into the MHz range or lower are either utilizing feedback elements or are build as distributed amplifiers , the latter can achieve typical bandwidths of 100KHz to 50GHz and output power of 30dBm the only downside
is cost as this topology requires a lot of real estate
?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]>
On Behalf Of Jim Ford via groups.io
Sent: Tuesday, March 22, 2022 5:26 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
?
Well, Gary did say "without a transformer".? If by transformer we mean a circuit to transform the low output impedance of the amplifier to 50 ohms, then he is correct.? Yes, I have worked with MMIC amplifiers that run on 5 V that put out
greater than +30 damage (=1 watt).
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
Date: 3/22/22 3:12 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement
Wrong !
There are several MMICs that can drive 20dBm and higher over the desired frequency range operating below 12V
?
?
My amplifier (as the amplifier by Dasaro Designs) replaces the output hybrid only. The part I used was the BFU590QX, from Digikey.? All three of these amplifiers require 2 stages to replace the output hybrid.
Unlike the Dasaro Designs amplifier, mine is not contained in a shielded enclosure, which allowed me a bit more area. To help remove the heat I have screwed a block of aluminum on the top cover that just contacts the top of the three transistors, with a
thermal pad between the aluminum and transistor case. Not a great solution, but then again we need to draw only about 0.6 watts from each of the two output transistors, about half that from the input transistor. Not a great solution, but it should be adequate
to hold the die temperature down.
+20 dBm is 2.25 Vrms, or 6.32 V peak to peak. You can't get +20 dBm from a +5 V supply without a transformer. A MMIC operating at perhaps less than 12 volts will not be able to provide +20 dBm.
Gary Appel
On 3/22/2022 11:24 AM, DB via groups.io wrote:
Hi Gary,
Thanks for posting your design of the output amp using BFU590Q's.? It looks like the BFU590Q are also becoming hard to obtain as I only saw one supplier had any in stock (BFU590QX only).
I was curious if your design is replacing both the preamp and final output amps inside the A6 module or just the final output amp.? On my 8601, It appears that both of the modules have an issue,so hoping that a cascade set of 2 or 3 MMIC's might work.? I have
a good signal level input into the A6 module.
Thanks,
DB
|
Re: Question about MMIC amp design for HP 8601a output replacement
Actually I found designing wideband circuits always to be fun , its actually not as quite as hard as you think if you got the right design tools
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Gary Appel via groups.io Sent: Tuesday, March 22, 2022 5:49 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Question about MMIC amp design for HP 8601a output replacement I guess I was making an assumption. This application requires a three decade bandwidth. The amplifier must drive a 50 ohm load, and must be capable of swinging at least 6.32 V peak to peak. This is met by each of these three amplifiers. Life is easier with a narrow bandwidth. Gary Appel On 3/22/2022 12:25 PM, Jim Ford wrote: Well, Gary did say "without a transformer".? If by transformer we mean
a circuit to transform the low output impedance of the amplifier to 50
ohms, then he is correct.? Yes, I have worked with MMIC amplifiers
that run on 5 V that put out greater than +30 damage (=1 watt).
Jim Ford
|
Re: Question about MMIC amp design for HP 8601a output replacement
Thanks Lothar Regarding available physical working space, I measured the A6 output module internals and attached some pics: The total available space within the inside walls of the A6 module is an absolute maximum of 1.125"? x 4.625" (28.58mm x 117.475mm) The maximum available space inside the output amp tin itself is only .75" x 1.125" (19.05mm x 28.58mm) I also included a pic of the meter scaling in case it might be helpful for the detector scaling or characterization.? The 8601 A9 board shows adjustments for the meter scaling? -10db (R181) and 0db (R131) and an ALC balance (R136), but no other ALC scaling adjustment. You may already have these, but thought I would post the links to the MiniCircuits S-Parameters for the MMIC's that I have on hand.? (not sure if these files have the low freq data you need) Thanks DB    
|
Re: HP8444A 1.55GHz oscillator
This is very useful - the oscillator adjusting instructions are rather different and much more detailed - especially the checks based on adjusting the power supply voltage.? Just need to see if I can locate a working thermistor head for a 431 for power measurements!
Alan
|
