HP 8642B develops issues when warming up
When cool this generator powers up with no problems but I notice when I leave it on for about an hour and the internals start to build up heat, symptoms started to occur. The A16 module was flashing on the screen transient failure and when I restarted A19 indicated a test failure. However throughout this the generator was still working. So I let everything cool down for a while and everything runs just fine again, no transient failures or any failed tests, the generator runs like new again when cooled off. Perhaps some capacitors are in question or maybe some IC's or transistors are becoming thermally unstable.
This is similar to the problems I had with a desktop video card, when it would get warm the video would go corrupt and everything would lock up. I attempted the oven trick when I reviewed that others had similar issues and it worked.
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Re: [RSGBTechnical] Some suspiciously cheap RF test kit on eBay UK
Dr. David Kirkby from Kirkby Microwave Ltd
Follow the E-bay link to the seller's shop - it gets odder and odder.
Definitely one to avoid - even though the serial number of the analyser is
clearly visible.
Peter, G3UBX
This seems to be a regular occurrence on high end test kit. I have seen it many times. It usually occurs at a weekend when businesses are closed and so I guess less likely to spot their account has been hacked.?
Once I decided to play along, to see what happened on a Keighley 2002 8.5 digit multimeter. I claimed I would make the bank transfer requested, but could not do it within the 24 hours requested. With that the seller said he sent via FedEx, but would ask FedEx to return if he didn't receive the money. The email had a link that looked like the FedEx website, which showed the parcel in transit, but was clearly not the FedEx website
I "won" the auction for a faulty RF impedance analyzer at ?310
but needless to say I am not going to pay for it. If it was genuine it would be worth getting repaired, but of course it is not genuine.
Dave
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Re: Some suspiciously cheap RF test kit on eBay UK
I reported it to eBay who say they are aware that its a scam, as is pretty much everything else listed under his name. The scam items are all listed as being outside of the USA. As Paul says the genuine seller has posted a note saying that he's been hacked and that unless the listing is for engraving within the US it's a scam.
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Re: Some suspiciously cheap RF test kit on eBay UK
Its a scam - the payment method via external link is the tell.
Seen these many times before.
the buy now method violates eBay laws.
I suggest everyone clicks on the "Report Now" link so it gets removed ASAP.
the same scammer is posting quite a few adds, here's another one...
regards
Tim
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Re: Some suspiciously cheap RF test kit on eBay UK
Try to visit his shop. He says he has been hacked.
Paul G8AQA.
On 08/10/2018 08:58, Dr. David Kirkby
from Kirkby Microwave Ltd wrote:
A 9 GHz Agilent PNA network analyzer for ?2250.?
Note it is running as an auction, but the
auction says that it is buy it now. If anyone is bidding, I
would not send any money without contacting eBay first.
Dave, G8WRB.
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Re: Some suspiciously cheap RF test kit on eBay UK
There are many many items with that modus operandii. A month ago or so many were for HP3458a; frequently the same photo/item was located in multiple continents.
Apart from the point you mention, red flags:
* what has the other vendor sold
* very short term auction
* starting price <?10
* link to a disguised non-ebay site
toggle quoted message
Show quoted text
On 08/10/18 08:58, Dr. David Kirkby from Kirkby Microwave Ltd wrote: A 9 GHz Agilent PNA network analyzer for ?2250.
Note it is running as an auction, but the auction says that it is buy it now. If anyone is bidding, I would not send any money without contacting eBay first.
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Some suspiciously cheap RF test kit on eBay UK
Dr. David Kirkby from Kirkby Microwave Ltd
A 9 GHz Agilent PNA network analyzer for ?2250.?
Note it is running as an auction, but the auction says that it is buy it now. If anyone is bidding, I would not send any money without contacting eBay first.
Dave, G8WRB.
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Re: HP 8935 E6380A wont power up
Hi all,
I was pointed at the common culprit via Rick@Amtronix.
There are two small vertical PCB's on the main power board, on each of them is a 47uF electro that often fails. Both of mine measured about 12uF. Replacing both brought the unit back to life.
regards
Tim
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Show quoted text
On 2/10/2018 7:40 PM, Tim Tuck wrote: Hi all,
My trusty E6380A failed to proceed this morning and preliminary investigations as to the cause prove zip.
Do these things have a common fault I could go look for ?
Any pointers to what might be the cause ?
Any path to resolution gratefully appreciated.
Service manuals don't have schematics so that's not helpful.
thanks
Tim
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Re: 54501 Power Supply Schematic
It was actually a 54503 schematic that helped me with my 54542. ? Joe ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Mark Whitmore
Sent: Sunday, October 07, 2018 11:57 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] 54501 Power Supply Schematic? Many thanks to all for the replies.? Several years ago I repaired the same P/S in my 54502A using reverse engineering. brute force, and dumb luck but it took me weeks to do.? Recently the the supply in the 54501 failed and I discovered that it was identical to the 54502 so I swapped them since the 54502 had other problems.? Now I want to get the 54502 going and the P/S is the first step.? I will look at the 54542 schematic that Joe provided and see if it is similar to what I remember of the 54502.? Have not re-caped the sucker but will look into that approach after poking around a little.? The years ago failure turned out the be a shorted rectifier diode supplying the + (or might have been -)? 12 VDC.? I have a vague recollection of these power supplies being manufactured in Ireland or maybe Holland.
Regards,
Mark On 10/7/2018 12:31 PM, Tam Hanna wrote: Hello, not Asian, but Boeschert. ? With best regards Tam Hanna --- ? Enjoy electronics? Join 8300 other followers by visiting the Crazy Electronics Lab at On 07.10.2018 18:23, Artekmedia wrote: Mark? All anticdotal evidence says that the supply was not manufactured by HP but is instead a 3rd party drop ergo no HP schematics were ever released. As near as I can tell It supplies -/+ 5v, +/- 12v (2 buses), +15v, +3.5v. you might try taking it apart and looking for original asian manufacturer and model number and back track it that way. Or even reverse engineering it. The above have produced some results on other HP gear of the 90's era. Dave Artekmanuals On October 7, 2018 at 10:34 AM Mark Whitmore <m.e.whitmore@...> wrote:
I need to fix a dead power supply for my HP 54501.? Is a schematic available anywhere on Earth?
?
?
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Re: Hp 8648C with output level problems
Are you 100% sure it is unstable at all frequencies? I had one output board issue in an 8648C where one of the amps blew in one of the frequency doubler stages and became an attenuator. So it was down above 2GHz iirc.
Colby
On Sat, Oct 6, 2018, 1:36 PM george edmonds via Groups.Io <G6HIG= [email protected]> wrote: Hi Peter
First is the PSU OK for voltage and noise, well known problem with 8648X signal generators
73 George G6HIG
On Saturday, October 6, 2018 8:48 PM, Peter Hansen <oz1lpr@...> wrote:
Hello All I have a Well trusted HP 8648C signal generator I used for many years. It has the high output option (20dBm output). It has now low output around 2-3dBm output maximum and it is not stable in amplitude.
I have ruled out the Attenuator and Reverse power protection. I measure the power direct on the output module.
I heard about Failure of the output MMIC. Can anyone comment on that.
I have seen that MMIC type for sale on Alibaba page. Has anyone ever tried buying that component from them. Is it safe to assume the part is genuine ?
73 Peter OZ1LPR
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Re: 54501 Power Supply Schematic
Many thanks to all for the replies.? Several years ago I repaired
the same P/S in my 54502A using reverse engineering. brute force,
and dumb luck but it took me weeks to do.? Recently the the supply
in the 54501 failed and I discovered that it was identical to the
54502 so I swapped them since the 54502 had other problems.? Now I
want to get the 54502 going and the P/S is the first step.? I will
look at the 54542 schematic that Joe provided and see if it is
similar to what I remember of the 54502.? Have not re-caped the
sucker but will look into that approach after poking around a
little.? The years ago failure turned out the be a shorted rectifier
diode supplying the + (or might have been -)? 12 VDC.? I have a
vague recollection of these power supplies being manufactured in
Ireland or maybe Holland.
Regards,
Mark
On 10/7/2018 12:31 PM, Tam Hanna wrote:
toggle quoted message
Show quoted text
Hello,
not Asian, but Boeschert.
With best regards
Tam Hanna
---
Enjoy electronics? Join 8300 other followers by visiting the Crazy Electronics Lab at
On 07.10.2018 18:23, Artekmedia
wrote:
Mark?
All anticdotal evidence says that the supply was not
manufactured by HP but is instead a 3rd party drop ergo no HP
schematics were ever released.
As near as I can tell It supplies -/+ 5v, +/- 12v (2 buses),
+15v, +3.5v. you might try taking it apart and looking for
original asian manufacturer and model number and back track it
that way. Or even reverse engineering it. The above have
produced some results on other HP gear of the 90's era.
Dave
Artekmanuals
On October 7, 2018 at 10:34 AM Mark
Whitmore <m.e.whitmore@...>
wrote:
I need to fix a dead power supply for my HP 54501.? Is a
schematic available anywhere on Earth?
|
Re: 54501 Power Supply Schematic
What Tam said.
You might even have to unsolder one of the trimpots near the forest of electrolytics to clean under it.? I used the DMM on ohms to check for conductivity between traces - one probe to a pad and drag the other around on the solder resist.? You'll be surprised how far the electrolyte contamination goes, giving readings in the 100s of KOhms to MOhms.? The contamination is invisible.
Here is the list of caps I used:
Index Quantity Part Number Description Customer Reference Available Quantity Backorder Quantity Unit Price USD Extended Price USD 1 14 565-1823-ND CAP ALUM 1000UF 20% 35V RADIAL 14 0 0.81900 11.47 2 2 565-1589-ND CAP ALUM 2200UF 20% 35V RADIAL 2 0 1.49000 2.98 3 1 565-1297-ND CAP ALUM 2200UF 20% 16V RADIAL 1 0 0.83000 0.83 4 3 565-1766-ND CAP ALUM 6800UF 20% 10V RADIAL 3 0 1.76000 5.28
The big primary side caps are probably OK.
The same power supply was used in the 1650B; they were plentiful and cheap on ebay, but such a supply will also die eventually, so you might as well fix the one you have.
There is more information and a hand drawn reverse engineered schematic here:
These supplies were used in many of the 545XX series oscilloscopes as well as at least the 1650B logic analyzer.? You have to search under 54501A, 54502A etc. to find the information.? Mine is a 54510A.
On Sun, Oct 7, 2018 at 7:38 AM Tam Hanna < tamhan@...> wrote:
Did we recap the fucker?
With these Boeschert cartridges, usually you need to gib the caps
first. Then, wash the remaining electrolyte from the top of the
PCB and the bottom, as the creep currents can fuck up the three
terminal regulators.
Tam
With best regards
Tam Hanna
---
Enjoy electronics? Join 8300 other followers by visiting the Crazy Electronics Lab at
On 07.10.2018 16:34, Mark Whitmore
wrote:
I need to fix a dead power supply for my HP 54501.? Is a schematic
available anywhere on Earth?
|
Re: 54501 Power Supply Schematic
Hello,
not Asian, but Boeschert.
With best regards
Tam Hanna
---
Enjoy electronics? Join 8300 other followers by visiting the Crazy Electronics Lab at
On 07.10.2018 18:23, Artekmedia wrote:
toggle quoted message
Show quoted text
Mark?
All anticdotal evidence says that the supply was not
manufactured by HP but is instead a 3rd party drop ergo no HP
schematics were ever released.
As near as I can tell It supplies -/+ 5v, +/- 12v (2 buses),
+15v, +3.5v. you might try taking it apart and looking for
original asian manufacturer and model number and back track it
that way. Or even reverse engineering it. The above have
produced some results on other HP gear of the 90's era.
Dave
Artekmanuals
On October 7, 2018 at 10:34 AM Mark
Whitmore <m.e.whitmore@...> wrote:
I need to fix a dead power supply for my HP 54501.? Is a
schematic available anywhere on Earth?
|
Re: 54501 Power Supply Schematic
Mark? All anticdotal evidence says that the supply was not manufactured by HP but is instead a 3rd party drop ergo no HP schematics were ever released. As near as I can tell It supplies -/+ 5v, +/- 12v (2 buses), +15v, +3.5v. you might try taking it apart and looking for original asian manufacturer and model number and back track it that way. Or even reverse engineering it. The above have produced some results on other HP gear of the 90's era. Dave Artekmanuals
On October 7, 2018 at 10:34 AM Mark Whitmore <m.e.whitmore@...> wrote:
I need to fix a dead power supply for my HP 54501.? Is a schematic available anywhere on Earth?
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8753D and 5086-7934 oscillator
For those following along at home, the problem with my 8753D “No R Found” has turned out to be the?5086-7934 oscillator. I ordered one up from a seller on eBay, installed it in <10 minutes, and all is well again.?
As these oscillators typically go for well in excess of $700, I thought I’d share that, should you need one, the seller I got mine from has another, guaranteed, listed for the same $550 buy it now, but took well less than that as an offer.?
Anyway, best of luck! KI2L?
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Re: 54501 Power Supply Schematic
Did we recap the fucker?
With these Boeschert cartridges, usually you need to gib the caps
first. Then, wash the remaining electrolyte from the top of the
PCB and the bottom, as the creep currents can fuck up the three
terminal regulators.
Tam
With best regards
Tam Hanna
---
Enjoy electronics? Join 8300 other followers by visiting the Crazy Electronics Lab at
On 07.10.2018 16:34, Mark Whitmore
wrote:
toggle quoted message
Show quoted text
I need to fix a dead power supply for my HP 54501.? Is a schematic
available anywhere on Earth?
|
54501 Power Supply Schematic
I need to fix a dead power supply for my HP 54501.? Is a schematic available anywhere on Earth?
|
Re: Calibration of 4285A Precision LCR meter 75 kHZ to 30 MHz. 0.1%
Dr. David Kirkby from Kirkby Microwave Ltd
On Sun, 7 Oct 2018 at 13:47, Dr. David Kirkby < drkirkby@...> wrote: All the above said, my main aim is to find out if this meter is okay, since it was bought used, at a not insigificant price. (I paid ?1650 for it, plus shipping and taxes).
Oops, I paid $1650 (USD) for the Agilent 4285A. Add on taxes and international shipping from the USA to the UK, and it cost a fair bit of money. So its worth spending about ?250 to get it calibratied - despite I have some reservations about a calibration that does not have uncertainties.
-- Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892
Tel 01621-680100 / +44 1621-680100
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Re: Calibration of 4285A Precision LCR meter 75 kHZ to 30 MHz. 0.1%
Dr. David Kirkby from Kirkby Microwave Ltd
On Sun, 30 Sep 2018 at 23:32, Dr. David Kirkby < drkirkby@...> wrote: The cal certificate has test data but is just 8 pages in length - see attached.
Can you, or anyone else make any sense of it? The file was downloaded from the Keysight website. One can also download a small cal certificate, which is only a couple of pages. That contains no test data, but this one does have test data.
I have had some sort of response from Keysight on this.
"Rather than the 04285-61001 accessory we use the 100ohm resistor from a calibrated resistor set (42030A) for our testing. As the open and short from the 42030A are used during the calibration, for practical reasons it’s easy to also use the 100ohm resistor. Also, it seems it may have been an oversight on the 6 year old results that the Customer has from the US where the 20cm AIRLINE from the 16342A kit is missing from the equipment used list."
It still does not explain
1) Why there is not the results from a single resistor measurement on the calibration certificate.
2) Why the 04285-61001 resistor, which was a standard accessory supplied with the LCR meter, is not calibrated.
Also, Keysight in the UK can't provide a calibration with uncertainties.
All the above said, my main aim is to find out if this meter is okay, since it was bought used, at a not insigificant price. (I paid ?1650 for it, plus shipping and taxes). So it is worth abut the ?250 or so to get it "calibrated", if only for the fact that the calibration should cover uncover any faults.
? -- Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892
Tel 01621-680100 / +44 1621-680100
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Re: Cleaning RF bits (attenuators, connectors, etc.)
Note that for a lot of dirt the lower grades of IPA work better than pure (99.9%). Use 80% IPA for first appliaction with the 99% for the final? clean to absorb the water. You can't get IPA purer than 91% by distillation, the purer grades are dryed chemically hence the higher cost.
I find Methanol works well on the decayed foam and citrus turpene (label remover) for labels.
Robert G8RPI.
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bownes