¿ªÔÆÌåÓý

Date

Re: HP-8753E R Channel Output Free Running

 

This one was solved this morning. It did not like the CAL data from the 8753E which this board has come from. I loaded the constants which came from the host machine and this seemed to resolve it.?

On Saturday, February 19, 2022, 11:34:35 PM EST, Rich Miller via groups.io <av8torrich@...> wrote:


Despite my initial success making progress on the EEPROM, it appears Murphy has struck. I started getting an error regarding the R Channel Input on my 8753E. When I plugged the R Channel output into my Spectrum Analyzer, I get the result as seen in the picture attached. Looks to me like something is free running at 2.55GHz or so.

I have the VNA in zero span at a frequency of 50MHz. As you will note the signal seems to be jumping all over based on my Max Hold capture. The primary signal is consistently at or around 2.5GHz (close to it), but makes massive excursions.??

I suppose not good deed goes unpunished! Time to start chasing this down.

Rich?


Re: Mixing 'n' matching S parameter test sets

 

?I have to go against the the nay-sayers.
There is no reason why you cannot use the 85046A with the 8754A. The only issue is controlling it. Fortunatly the interface is really simple. You need 4 bits of data and a strobe (trigger) plus a 22V unregulated supply. Three of the bits are for the attenuator (10, 20, 40dB) and one for the RF relay / switch. So you need as a minimum 4 toggle switches and a push button switch plus DC power supply. If you want to get fancy a 3 bit Binary / BCD switch for the attenuator will allow direct selection.? You just set the switches and push the button.
A quick look at the manual and schematic should make it clear.

Robert G8RPI.


Re: Storage Cap Ripple

 

¿ªÔÆÌåÓý

A sawtooth ripple on the unregulated DC is exactly what you should see -- the cap rapidly charges up when the rectifier forward biases, but slowly discharges once the rectifier goes into reverse bias.

If the regulator always regulates, then that ripple is benign. That is, ripple on the unregulated DC is to be expected. If ripple doesn't show up on the output, then the regulator is doing its job.

--Cheers,
Tom
-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
On 2/20/2022 04:48, Jinxie wrote:

Hi all,

This relates specifically to the 8566B but is no doubt relevant to all analysers with linear power supplies.
My 8566B has been suffering from the infamous YTO ulock error and it was suggested on some Youtube clip that it would be a good idea to scope the power rails. To cut a long story short, I was seeing ripple further down the line (in the direction away from the main PSU section) so I decided to go back to the start and scope the main storage electrolytics (you know, the big, beefy ones to use the correct terminology). Anyway, they *all* have ripple on them and it's more than I would expect, at around 10% of the DC voltage. So for example on 12VDC I'm seeing just over a volt P-P of ripple. Furthermore, it's not sine waveform either, but saw-tooth! I did check these caps for ESR and capacitance some time ago with my Peak ESR meter and they all came out OK as I recall. So I'm not sure what to check next. Any suggestions? I've got all the service manuals and whatnot on DVD but find it much harder to follow what wiring goes to where without a proper hard-copy book type manual to flick through. :(


Storage Cap Ripple

 

Hi all,

This relates specifically to the 8566B but is no doubt relevant to all analysers with linear power supplies.
My 8566B has been suffering from the infamous YTO ulock error and it was suggested on some Youtube clip that it would be a good idea to scope the power rails. To cut a long story short, I was seeing ripple further down the line (in the direction away from the main PSU section) so I decided to go back to the start and scope the main storage electrolytics (you know, the big, beefy ones to use the correct terminology). Anyway, they *all* have ripple on them and it's more than I would expect, at around 10% of the DC voltage. So for example on 12VDC I'm seeing just over a volt P-P of ripple. Furthermore, it's not sine waveform either, but saw-tooth! I did check these caps for ESR and capacitance some time ago with my Peak ESR meter and they all came out OK as I recall. So I'm not sure what to check next. Any suggestions? I've got all the service manuals and whatnot on DVD but find it much harder to follow what wiring goes to where without a proper hard-copy book type manual to flick through. :(


Re: Mixing 'n' matching S parameter test sets

 

The antiquity of the 8754A is part of the appeal, though! It's closer to the fundamentals of network analysis and there are no abstraction levels between the operator and the machine as is the case with more modern kit. I should mention I'm heavily into vintage test equipment which has a certain appeal for my personally, though it wouldn't suit everyone of course.
I bought the 8754A and the storage normaliser for it many years ago but since I never had the S parameter test set for it, I never did much with it. More recently I acquired an 8753 series VNA together with the matching S parameter test set and it just occurred to me that I could fully check out the old VNA by hooking it up to the newer test set if that was possible without causing damage to either component. So there's a bit of background for you. Unfortunately from what's been posted to this thread it appears they just won't work together, however. :(


Re: HP ic needed

 

The 1820-2131 is used in the 5315A/B and 5316A Universal Counters. I'm not aware if it being used in any other instrument.
Also known as the MRC, "Multiple Register Counter" and described with some detail in the January 1979 issue of HPJournal.
Pure unobtainum, I'm afraid ...

Joel Setton


Re: Good Progress on 8753E EEPROM - Need More Guidance

 

Rich,

the reason for not getting the results you expect is that you are assuming that 8753D and 8753E has the same EEPROM layout.

I recommend using the 8753D EEPROM layout as inspiration only and that you focus on analyzing the differences in the two EEPROMs you have, to find what bits to flip.

Best regards
Marcus


Re: HP8903B - Plotting from HP-IB

 

¿ªÔÆÌåÓý

Hi Tony

Please contact me off group

Hardy

?

Fra: [email protected] [mailto:[email protected]] P? vegne af Tony Goodhew
Sendt: 18. februar 2022 15:52
Til: [email protected]
Emne: Re: [HP-Agilent-Keysight-equipment] HP8903B - Plotting from HP-IB

?

Thanks Dave, for the info - I'll have to take a look into VISA for the ProLogix - I moved from a Prologix to an 82357 and ended up with an NI GPIB-ENET/1000 - It'd be good to have the possibility of using the Prologix as well.

Attilio - When you get the Keysight IO Libraries Suite installed you may still need to configure the instrument to use address 14 or modify the settings used by Pete's software - In VEE there is a thing called Instrument Manager and you can do that - Pete has information on his website about it.

Good luck with it.

TonyG


Virusfri.


HP-8753E R Channel Output Free Running

 

Despite my initial success making progress on the EEPROM, it appears Murphy has struck. I started getting an error regarding the R Channel Input on my 8753E. When I plugged the R Channel output into my Spectrum Analyzer, I get the result as seen in the picture attached. Looks to me like something is free running at 2.55GHz or so.

I have the VNA in zero span at a frequency of 50MHz. As you will note the signal seems to be jumping all over based on my Max Hold capture. The primary signal is consistently at or around 2.5GHz (close to it), but makes massive excursions.??

I suppose not good deed goes unpunished! Time to start chasing this down.

Rich?


Good Progress on 8753E EEPROM - Need More Guidance

 

All:

I made some excellent progress on my 8753E today. From the spare A9 CPU Board, I was able to read the XICOR EEPROM. This yielded the information I had been looking for. Since this is a spare A9 Board, and I have an image of U402 I decided to use the following data to write some changes to the EEPROM:


The A9 CPU board which has become my spare came from a HP-8753E that did not have OPT6 but did have OPT11. My 8753E, which I has had OPT06, and I am trying to add OPT10 and OPT2. As an experiment I did the following to the spare A9 CPU Board U402 Binary File:

  • Address 0x00 - 0x02: 01 01 01 - This was changed from 00 00 00, these are the first three bits before the serial number.
  • Address 0xBC 00 - This was changed from 01 which invoked OPT11, which my VNA cannot use as it's only a two port instrument.?


The result of the changes above gives a result that I did not expect. It did remove OPT 11. It added, OPT10 (Posts on Instruments Display next to serial number.), but there is no OPT6 (6GHz) or OPT2 (Harmonic).?

My understanding is all 8753E's have the ability to be upgraded to OPT6 with existing hardware and the bits at address 0x00 - 0x02 should have activated OPT10, OPT6, OPT2. I still find this to be great progress and am encouraged by the result, as it means I am going in the right direction.?

I wonder if someone who has played with these 8753E's can comment on these results, and possibly tell me what additional bits must be thrown to activate OPT6 and OPT2.

Thanks!

Rich?


Re: HP ic needed

 

It might help if one knew what instrument the ic is used in.

Sam Reaves
ARS W3OHM
Owner / Moderator of:
LeCroy Owners Group on Groups.io
Sencore Owners Group on Groups.io
Sprint Layout Group on Groups.io??
Pulsonix EDA Group on Groups.io
LPKF Owners Group on Groups.io
Electronics and Mechanical Hardware Design Engineering Manager
Staff Scientist Andritz Rolls Global Research Center (RETIRED)


Re: HP detector

 

¿ªÔÆÌåÓý

Hi Bruce

You are probably correct from memory it was the first HP plug in I was repairing and it was in the trigger CCT? if the fault was there from manufacture

The scope would have had a bad history as not having a good sweep trigger it was? a Paine to find the fault and I couldn't find? a replacement so just turned the original around and all was OK

Regards Paul

?

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Bruce
Sent: 20 February 2022 00:32
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP detector

Another possibility is that the diode was mismarked, but correctly positioned in an auto-insertion pack.? Automation would ignore the mismarking, and final inspection could miss it.

Cheers!

Bruce

Quoting tmillermdems <tmiller11147@...>:

> /I have seen mismarked diodes as well as equipment that was never

> tested (or powered up). It's rare but it happens./

>

> /Regards/

>

> On 2/19/2022 5:14 PM, Paul Bicknell wrote:

>>

>> Hi just a line hear hopefully without stealing the thread when

>> repairing a HP 180 scope plug in one diode was reverse polarity to

>> its marking compared to others in the same plug in

>>

>> Reversing the diode fixed the problem

>>

>> My question is how did this change polarity as I assume it was

>> correct at manufacture of the plug in? otherwise the plugin should

>> have failed end of line testing

>>

>> Regards Paul

>>

>> *From:*[email protected]

>> [mailto:[email protected]] *On Behalf Of *Dave

>> Wright

>> *Sent:* 19 February 2022 15:13

>> *To:* [email protected]

>> *Subject:* Re: [HP-Agilent-Keysight-equipment] HP detector

>>

>> Tom,

>>

>> Thanks for the confirmation..!

>>

>> And, can you comment on if / how the whisker tip geometry might

>> affect characteristics..? I'm wondering if a 'blunt' tip at the

>> contact point might alter performance at high frequencies...

>>

>> _Dave KC6UPS

>>

>>

>

> --

> This email has been checked for viruses by Avast antivirus software.

>

>

>

>






Re: HP detector

 

Another possibility is that the diode was mismarked, but correctly positioned in an auto-insertion pack. Automation would ignore the mismarking, and final inspection could miss it.

Cheers!

Bruce

Quoting tmillermdems <tmiller11147@...>:

/I have seen mismarked diodes as well as equipment that was never tested (or powered up). It's rare but it happens./

/Regards/

On 2/19/2022 5:14 PM, Paul Bicknell wrote:

Hi just a line hear hopefully without stealing the thread when repairing a HP 180 scope plug in one diode was reverse polarity to its marking compared to others in the same plug in

Reversing the diode fixed the problem

My question is how did this change polarity as I assume it was correct at manufacture of the plug in? otherwise the plugin should have failed end of line testing

Regards Paul

*From:*[email protected] [mailto:[email protected]] *On Behalf Of *Dave Wright
*Sent:* 19 February 2022 15:13
*To:* [email protected]
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP detector

Tom,

Thanks for the confirmation..!

And, can you comment on if / how the whisker tip geometry might affect characteristics..? I'm wondering if a 'blunt' tip at the contact point might alter performance at high frequencies...

_Dave KC6UPS

--
This email has been checked for viruses by Avast antivirus software.




Re: Mixing 'n' matching S parameter test sets

 

¿ªÔÆÌåÓý

John Lyles¡­

?

¡°The 85046A was made for the 8753 series of VNAs and has switching of signal direction built in, as well as four port capability.¡±

?

Please explain the 4-port capability. I was not aware it had that and would like to know more.

?

Thanks.

?

From: [email protected] <[email protected]> On Behalf Of John Lyles
Sent: Saturday, February 19, 2022 4:07 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Mixing 'n' matching S parameter test sets

?

Those are completely different generation VNAs. The 8754A is strickly a manual VNA in that if you want calibration of cables and fixtures you will need to have the storage normalizer box or you can use grease pencils on an overlay on the screen! The 85046A was made for the 8753 series of VNAs and has switching of signal direction built in, as well as four port capability. Your 8754A doesn't have the drivers to do that. Just because it has the type N connectors for the RF ports, it doesn't have the smarts to drive the switches. When 8754A was developed, it was impossible to predict what the future microprocessor-based VNA would be. The 85044A or B transmission/reflection test set will work with it as it has no switching and has only an attenuator with a knob. They can be found relatively cheap. I had a couple of them, sold one and now I use the other with my Rigol RSA-3000 series spectrum analyzer/tracking generator as a SNA (scalar network analyzer) to 3 GHz.


Re: HP ic needed

 

¿ªÔÆÌåÓý

Lol, Dave!

Jim



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: Dave McGuire <mcguire@...>
Date: 2/19/22 12:25 PM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed


?? Could be. ;)? The OP sent a terse and rude message with a picture,
saying "I need this".? Nothing else.? I mean, I'm sorry, but I'm not
going to interrupt my day to help when the request is made in such a way.

?? But to his credit, he rephrased and re-posted it, flawlessly, and is
now redeemed in my book.? So I don't have to find him and slash his
tires the next time I'm in NJ. ;)

???????????? -Dave

On 2/19/22 15:22, Mike Feher wrote:
> Sorry, sometimes I miss subtle sarcasm, or even jokes. Must be my Hungarian upbringing, HI.? 73 - Mike
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell NJ 07731
> 848-245-9115
>
> -----Original Message-----
> From: [email protected] <[email protected]> On Behalf Of Dave McGuire
> Sent: Saturday, February 19, 2022 3:05 PM
> To: [email protected]
> Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed
>
>
>???? Exactly. :)
>
>??????????? -Dave
>
> On 2/18/22 23:03, Jim Ford wrote:
>> Dave just put into words the whole thought.?? Right, Dave?
>>
>> Jim Ford
>>
>>
>>
>> Sent from my T-Mobile 4G LTE Device
>>
>>
>> -------- Original message --------
>> From: Mike Feher <n4fs@...>
>> Date: 2/18/22 7:48 PM (GMT-08:00)
>> To: [email protected]
>> Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed
>>
>> I do not get it. What is he looking for and how did Dave fix it? 73 -
>> Mike
>>
>> Mike B. Feher, N4FS
>> 89 Arnold Blvd.
>> Howell NJ 07731
>> 848-245-9115
>>
>> -----Original Message-----
>> From: [email protected]
>> <[email protected]> On Behalf Of Dave McGuire
>> Sent: Friday, February 18, 2022 10:22 PM
>> To: [email protected]
>> Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed
>>
>> On February 18, 2022 10:08:38 PM "Andrew Curlik" <kb2lmn@...> wrote:
>>?? > I¡¯m looking for the following IC.
>>
>>???? Wow.
>>
>>???? "HI everyone, I'm looking for the IC in the attached photo to fix
>> one of my instruments. Would anyone happen to have one to spare? Will
>> pay a reasonable price, swap, etc. Thanks, I hope everyone is having a
>> nice Friday night."
>>
>>???? There.? Fixed that for ya.
>>
>>???? Sheesh.
>>
>>???????????? -Dave
>>
>> --
>> Dave McGuire, AK4HZ
>> New Kensington, PA
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> --
> Dave McGuire, AK4HZ
> New Kensington, PA
>
>
>
>
>
>
>
>
>
>


--
Dave McGuire, AK4HZ
New Kensington, PA






Re: HP ic needed

 

Yeah, he was 100% fine after that. No hard feelings.

-Dave

On 2/19/22 17:54, Paul Bicknell wrote:
Hi Dave and all I did PM him and gave him a bit of guidance so future postings should be OK
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Dave McGuire
Sent: 19 February 2022 20:25
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed
Could be. ;) The OP sent a terse and rude message with a picture, saying "I need this". Nothing else. I mean, I'm sorry, but I'm not going to interrupt my day to help when the request is made in such a way.
But to his credit, he rephrased and re-posted it, flawlessly, and is now redeemed in my book. So I don't have to find him and slash his tires the next time I'm in NJ. ;)
-Dave
On 2/19/22 15:22, Mike Feher wrote:
Sorry, sometimes I miss subtle sarcasm, or even jokes. Must be my
Hungarian upbringing, HI. 73 - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115

-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
Sent: Saturday, February 19, 2022 3:05 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed


Exactly. :)

-Dave

On 2/18/22 23:03, Jim Ford wrote:
Dave just put into words the whole thought. Right, Dave?

Jim Ford



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: Mike Feher <n4fs@...>
Date: 2/18/22 7:48 PM (GMT-08:00)
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed

I do not get it. What is he looking for and how did Dave fix it? 73 -
Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115

-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
Sent: Friday, February 18, 2022 10:22 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed

On February 18, 2022 10:08:38 PM "Andrew Curlik" <kb2lmn@...> wrote:
> I¡¯m looking for the following IC.

Wow.

"HI everyone, I'm looking for the IC in the attached photo to fix
one of my instruments. Would anyone happen to have one to spare? Will
pay a reasonable price, swap, etc. Thanks, I hope everyone is having
a nice Friday night."

There. Fixed that for ya.

Sheesh.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA













--
Dave McGuire, AK4HZ
New Kensington, PA









--
Dave McGuire, AK4HZ
New Kensington, PA
--
Dave McGuire, AK4HZ
New Kensington, PA


Re: HP ic needed

 

Hi Dave and all I did PM him and gave him a bit of guidance so future postings should be OK

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Dave McGuire
Sent: 19 February 2022 20:25
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed


Could be. ;) The OP sent a terse and rude message with a picture, saying "I need this". Nothing else. I mean, I'm sorry, but I'm not going to interrupt my day to help when the request is made in such a way.

But to his credit, he rephrased and re-posted it, flawlessly, and is now redeemed in my book. So I don't have to find him and slash his tires the next time I'm in NJ. ;)

-Dave

On 2/19/22 15:22, Mike Feher wrote:
Sorry, sometimes I miss subtle sarcasm, or even jokes. Must be my
Hungarian upbringing, HI. 73 - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115

-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
Sent: Saturday, February 19, 2022 3:05 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed


Exactly. :)

-Dave

On 2/18/22 23:03, Jim Ford wrote:
Dave just put into words the whole thought. Right, Dave?

Jim Ford



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: Mike Feher <n4fs@...>
Date: 2/18/22 7:48 PM (GMT-08:00)
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed

I do not get it. What is he looking for and how did Dave fix it? 73 -
Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115

-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
Sent: Friday, February 18, 2022 10:22 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP ic needed

On February 18, 2022 10:08:38 PM "Andrew Curlik" <kb2lmn@...> wrote:
> I¡¯m looking for the following IC.

Wow.

"HI everyone, I'm looking for the IC in the attached photo to fix
one of my instruments. Would anyone happen to have one to spare? Will
pay a reasonable price, swap, etc. Thanks, I hope everyone is having
a nice Friday night."

There. Fixed that for ya.

Sheesh.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA













--
Dave McGuire, AK4HZ
New Kensington, PA










--
Dave McGuire, AK4HZ
New Kensington, PA


Re: HP8568B does not start.

 

Hi Bruce,

Thank you for your reply. The CPU boards were identical and swapping them confirmed the dead 8568B chassis was indeed fully functional. I'll keep working on the A15 and perhaps I might find what's wrong with it.

@Don Bitters - Thanks for your suggestion but this test confirms that the internal 10MHz reference is functional.

Regards

Lou
VK3ALB


On Sat, Feb 19, 2022 at 5:46 PM Bruce <bruce@...> wrote:
Lou -
Possibly - I'm more familiar with the 8566.? Many times the number of?
the CPU board was changed because of chip substitution with no?
external function change.

Here are things to check:
1) Are the first 4 digits of the SN the same
2) Are the motherboard part numbers the same
3) Are the CPU numbers the same
4) Are the FIRMWARE versions the same

If 2,2 and 4 are identical, absolutely OK to change.? If 2 and 4 are?
the same but 3 is different, probably OK - go to Keysight find a part?
site, put in the part number of the EXISTING CPU and see if the?
WORKING CPU is a substitute = OK.
If 4 are the same it is also probably OK

Just collect all the data B4 doing the sub.

Cheers!

Bruce


Quoting Lou Blasco <vk3alb@...>:

> Hi All,
>
> I was given a HP8568B that doesn't work.
>
> The 85662 display section is good but it seems the CPU in the analyzer box
> does not boot. The lithium battery on A15 leaked and was removed at some
> stage in the past. The acid got under the clock module and ate the leads
> away. The rest of the board looks ok so I pulled the clock chip and
> substituted an external 14.7456MHz oscillator for the purpose of testing
> but still nothing from the CPU.
>
> All power supplies measure good. Both INSTR CHECK LEDs remain on. None of
> the LEDs on A15 come on ever even if I push the INSTRUMENT PRESET key. All
> the yellow leds on both units remain illuminated.
>
> I don't have extender cards, just a 'scope and a meter. However I do have
> another functional 8568B.
>
> Is it reasonable to take a good A15 card from one machine and put it in
> another for troubleshooting purposes? Besides the terrifying risk that I
> might end up with two dead analyzers is there anything else I should
> consider?
>
> Regards
>
> Lou
> VK3ALB
>
>
>









Re: HP 6033A DOA

tmillermdems
 

¿ªÔÆÌåÓý

At least it wasn't the other way around. Set for 120 in 240 land.


Regards


On 2/19/2022 3:58 PM, Mark Bielman wrote:
It was the power config switches! (inside the unit)
Was set for 240V. Changed to 120V and AOK!!!

That was easy. ?

Mark


From: [email protected] <[email protected]> on behalf of Dave McGuire <mcguire@...>
Sent: Saturday, February 19, 2022 12:35 PM
To: [email protected] <[email protected]>
Subject: Re: [HP-Agilent-Keysight-equipment] HP 6033A DOA
?
On 2/19/22 14:15, Mark Bielman wrote:
> My HP 6033A arrived yesterday (from epay... "guaranteed to work"... HA!)
> and looks AOK but when powered up,
> ALL LEDs light up (normal) and stay that way! (not normal)
>
> Have not opened her up yet but looks like a uP related issue.
>
> Anyone ever work on these? I hope it's not a ROM/GAL issue!
>
> Might be a clue here as I do not "hear" any relay clicks...

?? I've not worked on one, but the schematics are available.? Being a
heavy unit that has just been shipped, the first thing that I'd check is
for something having dislodged inside; a cable, PCB, etc.

?? The next thing I'd check is main power.? Check the line voltage
configuration switches, and see if you get anything past the bridge
rectifiers.? Looking at the schematic, I see there are a few power rails
generated; check them all.? The +5V rail can apparently be isolated from
the rest of the unit using W2.

?? These are really nice power supplies; it's worth giving it some
attention.

???????????? -Dave

--
Dave McGuire, AK4HZ
New Kensington, PA








This email has been checked for viruses by Avast antivirus software.



Re: HP detector

tmillermdems
 

¿ªÔÆÌåÓý

I have seen mismarked diodes as well as equipment that was never tested (or powered up). It's rare but it happens.

Regards

On 2/19/2022 5:14 PM, Paul Bicknell wrote:

Hi just a line hear hopefully without stealing the thread when repairing a HP 180 scope plug in one diode was reverse polarity to its marking compared to others in the same plug in

Reversing the diode fixed the problem

My question is how did this change polarity as I assume it was correct at manufacture of the plug in? otherwise the plugin should have failed end of line testing

Regards Paul

?

From: [email protected] [mailto:[email protected]] On Behalf Of Dave Wright
Sent: 19 February 2022 15:13
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP detector

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Tom,

Thanks for the confirmation..!

And, can you comment on if / how the whisker tip geometry might affect characteristics..? I'm wondering if a 'blunt' tip at the contact point might alter performance at high frequencies...

_Dave KC6UPS




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