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Re: HP8920B Blowing Fuse

 

I would check at the input of the power supply for a shorted filter cap. or a shorted rectifier diode.

On 2025-04-02 9:01 pm, Jeff Acree via groups.io wrote:
Friends,
My beloved HP8920B RF Communications Test Set started blowing the 5A AC fuse today.? It blows as soon as you push the power switch.? I am wondering if there is a common problem I could look for.? Tomorrow I may try to see if it will run on 12VDC. It has a connector and switch for DC operation.? Any advice appreciated.
Thanks!
Jeff
--
This email has been checked for viruses by AVG antivirus software.
www.avg.com


Re: E5052A Power On Test (3.3V Bus Supply)

 

I was able to source some CS5208-1 from Kynix. Had good results ordering obsolete/obscure parts from them before:
?
Also finished designing some adapter boards to bring the A3 out of the chassis and allow for "hot" testing.?
They connect together using Samtec SFSD .050" wiring harnesses, which come in all sorts of lengths. Hopefully 24" of wire doesn't mess up signal integrity too much.?
?
?
?
?
I just ordered parts and boards. If its successful I'll share gerbers and BOM so others can use.?
?
In the mean time, does your firmware disassembly have any useful hints as to what that error means? Looks like its pointing out a particular .cpp file in the FW related to the A3.?
Also, if anyone has info on LEDs that would also be great. Wish I had a working unit to look at and compare which LEDs are lit/not lit. Of course service manual doesn't say anything.?


Re: Manuals for an HP3456B DMM?

 

Yes. There was a time when a 3458A was on my list of expensive instruments to acquire for my lab, but I ended up with the 3456A as an interim solution and it has fulfilled my needs. I wish I could find a replacement for the small aluminum panel on the RH side on which the binding posts are mounted because mine is badly and deeply scratched, but tha's a nit.

It sounds as if i should scan my 3456A manual and upload a copy of the PDF to the HP Wiki. I an in the process of scanning a Tektronix 7934 manual (the foldouts are tedious to properly scan), so the 3456A manual scan would be queued behind that.?

Everyone should own an HP 345xA, a Fluke 27 and af least one Simpson 260, lol.

DaveD
KC0WJN


On Wed, Apr 2, 2025 at 22:54 Dave McGuire via <mcguire=[email protected]> wrote:
On 4/2/25 22:48, Dave Daniel via wrote:
> They made 3455s, 3456s, 3457s and 3458s. I think but am not sure that
> these were all "A" models, i.e., 3456A. My understanding is that the
> 3458A is the (or one of) gold standard(s).

? ?The 3458A is indeed the gold standard, and one of the few instruments
to be made with all three names on the front.

> I own a 3456A.

? ?They are great meters, even (especially?) by today's standards.

? ? ? ? ? ? ? -Dave

--
Dave McGuire, AK4HZ
New Kensington, PA






Re: Manuals for an HP3456B DMM?

 

On 4/2/25 22:48, Dave Daniel via groups.io wrote:
They made 3455s, 3456s, 3457s and 3458s. I think but am not sure that these were all "A" models, i.e., 3456A. My understanding is that the 3458A is the (or one of) gold standard(s).
The 3458A is indeed the gold standard, and one of the few instruments to be made with all three names on the front.

I own a 3456A.
They are great meters, even (especially?) by today's standards.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA


Re: Manuals for an HP3456B DMM?

 

They made 3455s, 3456s, 3457s and 3458s. I think but am not sure that these were all "A" models, i.e., 3456A. My understanding is that the 3458A is the (or one of) gold standard(s).

I own a 3456A.

DaveD
KC0WJN


On Wed, Apr 2, 2025 at 21:35 Steve Byan via <stevebyan=[email protected]> wrote:
I had no idea they made a 3456B. Are you sure it isn’t a 3465B?


HP8920B Blowing Fuse

 

Friends,
?
My beloved HP8920B RF Communications Test Set started blowing the 5A AC fuse today.? It blows as soon as you push the power switch.? I am wondering if there is a common problem I could look for.? Tomorrow I may try to see if it will run on 12VDC.? It has a connector and switch for DC operation.? Any advice appreciated.
?
Thanks!
Jeff?


Re: Manuals for an HP3456B DMM?

 

I had no idea they made a 3456B. Are you sure it isn’t a 3465B?


Manuals for an HP3456B DMM?

 

Does anybody know where I can find manuals for an HP3456B DMM?
The HP site has a manual for the 3456A, how different is the 3456B from the 3456A?
?
Thanks,
BobH


Re: Success: Repair HP3455A Multimeter

 

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Thank you for posting your story, some other 3455 owner will benefit someday.

Dave Wise


From: [email protected] <[email protected]> on behalf of Ralf Rosche via groups.io <ralf.rosche@...>
Sent: Wednesday, April 2, 2025 11:49 AM
To: [email protected] <[email protected]>
Subject: [HP-Agilent-Keysight-equipment] Success: Repair HP3455A Multimeter
?
Hi all,
I checked U16 the latch connected to the driver U5 with a scooe.?
The output pin 15 ( connected to pin 9 of U5) was not stable and so I replaced U16.
Now the 3455 is working again.
At least no FET, only U6 and U16 replaced.
Ralf


Success: Repair HP3455A Multimeter

 

Hi all,
I checked U16 the latch connected to the driver U5 with a scooe.?
The output pin 15 ( connected to pin 9 of U5) was not stable and so I replaced U16.
Now the 3455 is working again.
At least no FET, only U6 and U16 replaced.
Ralf


Re: hp-410b, early manual

 

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Thanks Ron, that is the oldest 410B manual I've seen.? It's for early non-prefixed Serial Number?401 through 7228.

Dave Wise


From: [email protected] <[email protected]> on behalf of Ron na2o <groups.io@...>
Sent: Wednesday, April 2, 2025 10:11 AM
To: [email protected] <[email protected]>
Subject: [HP-Agilent-Keysight-equipment] hp-410b, early manual
?
In the course of refurbishing an old -410b, I was a bit confused in that my unit does not correspond to a manual stored here in our Files section.? So, I purchased a manual online and discovered that it matches the unit that I own, so I have scanned it and loaded into our files section today.? Cheers.
--
Ron Lawson


hp-410b, early manual

 

In the course of refurbishing an old -410b, I was a bit confused in that my unit does not correspond to a manual stored here in our Files section.? So, I purchased a manual online and discovered that it matches the unit that I own, so I have scanned it and loaded into our files section today.? Cheers.
--
Ron Lawson


Re: LCR Meter E4980A Power On Test Fail

 

Thanks Nigel, I have updated the firmware from A.04.00 to A.05.00. Unfortunately, the failure persisted. Since it was able to passed all other tests, except CPU[2]: 16 tests failed, it seems like a hardware issue on the CPU board? I will have to order some IC parts to replace on the CPU board.
?
Best regards,
KC


RF Alignment Failure in Agilent CXA signal analyzer N9000A

 

I have Agilent CXA Signal Analyzer N9000A, I'm getting these errors, please help.
?
I referred manual and it suggested to check 50Mhz with -24dB, But when I check in my equipment its showing 50Mhz with -60dB. While I trace it out it was across H270(HMC270MS8G) where I was getting 50Mhz with -60dB but near FPGA it is exact 50Mhz with -24dB, so does it represent there is problem with H270 or any other if yes please help me, And any blue print of this will help a-lot.
?


Re: Request HDD image for Agilent Infiniium DCA 86100C mainframe

 

I'm still looking..


Re: HP83712B EPROM content

 

No, it is not the same as for the 83732A. I tried but it is not working properly.
?


Re: HP83712B EPROM content

 

"tom_iphi via groups.io" <iphi@...> writes:

Hi,

does anyone happen to have the data of EPROMs U7 and U24 of the HP83712B?
I seem to have lost data...
ko4bb has


Not sure whether that's the same.


HP83712B EPROM content

 

Hi,
?
does anyone happen to have the data of EPROMs U7 and U24 of the HP83712B?
I seem to have lost data...
?
Tom


Re: HP 85047A test set on 8753A analyzer -- switch control board jumpers to retrofit for opt 009 (mechanical switch)

 

On Tue, 1 Apr 2025 at 03:06, David Feldman via <wb0gaz=[email protected]> wrote:
Working on a 85047A test set which needs to be retrofitted with mechanical switch 33311B,



Any suggestions at this point?


I have looked at the circuit diagram of the 85046A, and noticed a capacitor value changed between the mechanical and electronic relays. Could that be the problem??


Dave


Re: E5052A Power On Test (3.3V Bus Supply)

 

Appreciate the suggestion. I reinstalled the A3 and tried cycling all the PSU connectors, including the motherboard one. I also brushed a tiny dab of Deoxit D100 on each male pin and cycled the connectors a few times.
?
Unfortunately, no changes.?
?
I also checked all of the power supply test points that are made accessible. All of the voltages seemed present and at a reasonable level:
?
?
One thing I observed on the back of the A3 board are the presence of red LED. These seem to be connected to different power rails on the back of the board.
?
?
I noticed that 1 LED was very dim and the other was not lit. These are visible with the outer cover off, through the chassis air holes where the A3 is slotted.
?
The 2 LEDs in question are the bottom most ones, which are connected to the 2 TO-220 voltage regulators U18 and U19.
Not sure what the "normal" condition should be; are both normally lit when no issues are present?
?
?
U19 is an ON semi CS5208-1. Datasheet is as follows:
Compare to U18 which is an LT1085:
?
The CS5208-1 is not available anymore, but the LT1085/1084 are. As far as I can tell, these are nearly identical regulators?
The CS5208 is rated to higher currents (6V, 9A) while the LT1085/4 is tolerant of higher voltages (30V, 3/5A). However, the pinout and output divider adjustment equations are identical?
?
I can get the LT1084 on Digikey. Maybe its worth swapping both U18 and U19 out with new LT1084 and seeing if anything changes?