Re: HP 54512B (pair) repair

#150617

One of the two scopes is completely disassembled - head exploding emoji - and I have the old battery desoldered after confirming?it's fully depleted.?

I enclose pics with what I'm using for replacement. I probably would have been fine going with a 2032 type, but the 2430 I ended?up fitting just right (maybe a bit snug), and the pins of the holder actually match the PCB eyelets. So all is good.?

I couldn't figure out what exactly was the original battery model, as it's not legible even after removing the top tab, but its diameter is a bit over 23mm.?

I think this should work OK.

Back to the?actual troubleshooting now!

Radu.?

Show quoted text

On Fri, Feb 28, 2025 at 6:21?PM Roy J. Tellason, Sr. via <roy=[email protected]> wrote:

On Thursday 27 February 2025 04:09:31 pm Radu Bogdan Dicher via wrote:
> One other unfortunate effect of the spot-welding of the top tab is that the
> battery code is not visible. I can probably destroy the battery once out,
> and read the CRxyzt battery code, but would anyone have good info offhand
> on it?

You might find bits of this useful:

Scroll down to where they discuss coin and button cells:

"IEC designation numbers indicate the physical dimensions of the cylindrical cell. Cells less than one centimeter in height are assigned four-digit numbers, where the first two digits are the diameter in millimeters, while the last two digits are the height in tenths of millimeters. Taller cells are assigned five-digit numbers, where the first two digits are the diameter in millimeters, followed by the last three digits indicating the height in tenths of millimeters."

So the size of the battery will give you the info that you need.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

HP 54512B - battery replacement. .JPG

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

#150616

Watching this subject with interest.? Leo, you may want to check out OEWaves, Synergy Microwave, and Holzworth Instrumentation (now part of Maury Microwave) for ultralow PN sources and Rohde & Schwarz, OEWaves and Holzworth for measurement instruments.? Also, there are several source mfrs making sapphire resonant cavity oscillators.? You probably already know about these companies, but throwing the names out there just in case. Microchip (was Microsemi, was Symmetricomm, was Ball Efratom; correct me if I got that progression wrong) as well.

I bought one of your GPSDO models a few years ago; it's great!? Looking forward to getting one (or more) of your pulsers at some point.

I'm working on a synthesizer myself based on a long spool of optical fiber to get the ultralow phase noise.? The tradeoff is sidemodes, which are spurs in the microwave output.? I have an idea for a way to knock those down.? My goal is a low SWaP-C synth mainframe in a 3 rack unit box that can be expanded from 1 to 8 outputs DC to 18 GHz or so.? I just don't have the room for multiple 4 RU boxes (HPAK 8340, 8662, etc.)? Stay tuned!

Jim Ford

Laguna Hills, California, USA

On Sunday, March 2, 2025 at 06:41:24 AM CST, jmr via groups.io <jmrhzu@...> wrote:

I don't know if this helps, but I dug out the most recent Keysight calibration certificate for this E5052A and there is a noise floor test done at 70 MHz with correlation set to 1.
I'm not sure what is involved with this test or at what power level it is run at but the numbers for the noise floor seem to be very good! I don't have anything here that can replicate this test although I could probably design a low noise LC oscillator that could get close at a 1 MHz offset.
?
I generally design wideband single loop synthesisers up at VHF through UHF and the E5052A is easily good enough for stuff like this.

?

Re: HP 54512B

#150615

I don't believe at this point HP was providing component-level Service Manuals anymore. I'd love to see one and prove myself wrong, though.

Radu.?

Show quoted text

On Mon, Sep 6, 2021 at 3:01?PM <byterock@...> wrote:

Ok looks like they have added a few things since the last time I was there.? No schematic but a block diagram and trouble shooting guide unfortunetly my problem is there but in classic new-age electrinics it says 'Replace A1'? A1 being the main Circuit board. d'ho

Looks like I have a little reverse engineering to do.

Thanks??
Wolferl

Re: HP 8660B/86602B developed output stability problem, getting-started suggestion(s) request

#150614

Gary, WB2UAQ --- the advice to make adjustments while the board(s) are enclosed is right on (seeing the solenoid coil on the VCO board helped me see why toroid inductor self shielding property is helpful!

I still could not measure any (filtered/smoothed) voltage at or above 0 (section 5.33 begins by having the tech adjust A19R3 or A19R9 - not sure why "or" - on the VCO board to get 0 volts at the detector test point.) It still isn't evident that this is caused by electrical problem in circuitry.

I decided to try experimentally the following -

Connect A2TP13 (A15TP6) to scope 
Set frequency to 15.55 MHz (same as setting to 5.55 MHz, but didn't want to concern "out of range")
Set A19R3 (pretune) fully clockwise
Adjust A19R9 (detector) to see 50% duty cycle on scope
If A19R9 cannot reach 50% duty cycle (likely), adjust A19R3 slightly counter clockwise and repeat previous step

From this point

Watching scope, adjust frequency down towards 10.000 MHz, watching to see if duty cycle stays at least 20% from (0% or 100%) limit
Watching scope, adjust frequency up towards 19.999 MHz, watching to see if duty cycle stays at least 20% from (0% or 100%) limit
If either of the above exceeds limit (duty cycle gets close or to 0% or 100%), adjust A19R3 slightly counter clockwise, return to 15.55 MHz, adjust A19R9 back to 50% duty cycle, and repeat the previous 2 steps.

This may (well) be masking a problem I can't yet find, but seeing as at worst I get to try repair again, I'm going to put the unit back into it's (occasional) service.

(I do wish PLL unlock conditions were made visible without disassembly, but at least I know now to keep eye on frequency counter if anything is suspect...)

Thanks for everyone's suggestions and patience!

Dave

Re: 3708A Noise and Interference Test Set - Looking for a Service Manual

#150613

Someone must have scanned it, as there is a 3708A on feeBay listed with a CD of software & documentation, probably doesn't help much as you don't want another unit to go with it;

https://www.ebay.com/itm/326196086333

?

David

Re: Manual for HP 466A amplifier

#150612

John, if you’ll share your email address?with me, I’ll send the schematic.?

Jeremy?

N6WFO?

Show quoted text

On Sun, Mar 2, 2025 at 8:25?AM John Griessen via <john=[email protected]> wrote:

On 3/1/25 08:45, Jeremy Nichols via wrote:
> I have a paper copy of the HP-466A manual, serial prefix 226, and could copy the schematic for you.

I've got one of those amps and would like the schematic also.

--
John Griessen

Re: Manual for HP 466A amplifier

#150611

Good point. I’d rather patronize Artek and save us both time and money.?

Jeremy?

N6WFO

Show quoted text

On Sun, Mar 2, 2025 at 8:37?AM Dave McGuire via <mcguire=[email protected]> wrote:

On 3/1/25 23:06, Jeremy Nichols via wrote:
> Paper original will be sent to Dave McGuire on Monday.

? ?I don't mind getting it scanned at the museum, but does it still make
sense to do that after the revelation that Artek has it available?? I
hadn't checked before; I had assumed the OP had already done so.

? ? ? ? ? ? ? ?-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

Re: Manual for HP 466A amplifier

#150610

David,

?

The Artek manual for 466a is actually 00466-90003.? There's a typo on the website, I'll let Linda know.

It's for serial prefix 226 with backdating for 210, 044, and 019 prefixes.

?

Ron

?

Re: Manual for HP 466A amplifier

#150609

Dave,

?

The Artek manual for the HP 466A is for serial number prefix 226.

?

Ron

3708A Noise and Interference Test Set - Looking for a Service Manual

#150608

Hi,

?

I just pulled my 3708A off the shelf for a bit of a spit polish ready to sell it off and I'm looking for a service manual for the performance test and calibration procedures.

?

I can't seem to find anything but the Operating Manual in the usual places.

?

Does anyone have a digital copy of the service manual for this instrument?

?

Thanks!

Jared

Re: HP Agilent 8753ES VNA repair [Help]

#150607

开云体育

Hi,

?

Starting point VCXO are correct frequency with 40.000MHz.

At TP20 you have a frequency of 39.100MHz, and at the output of divider 40 you get 977.5kHz. This indicates, that the divider by 40 is correct but the frequency is wrong from VCO.

?

At output of mixer 40MHZ from VCXO is mixed with 39.100 MHz (>16 MHz?) to have around 900kHz (909kHz).

At output of mixer 40MHZ from VCXO is mixed with 39.280 MHz (< 16 MHz) you will have around 720kHz.

Mixer is OK, but bad frequency from VCO, and good frequency from VCXO.

?

Phase detector received bad feedback frequency from VCO (example for HIGH band, 909kHz instead 160kHz)… The PLL is open loop for a reason unknown at this time.

?

Correction: TP6 is a TP from output mixer (H160kHz, L=4kHz), and TP7 is the reference for PLL (40MHz from VCXO divided by 250 for HIGH BAND and divided by 10,000 to have 4kHz).

?

First question: Is the reference coming from the VCXO divided to have 160kHz for the high band and 4kHz for the low band correct at TP7?

The VCO is functional, but the frequencies are incorrect, can the VCO range cover the expected frequency band, between 39.84 and 39.996 MHz.

The electrical schematic shows the PLL section of an 8753D, which should be quite similar if not identical for the 8753ES.

A way to test the VCO range should be found…remove serial resistor near the TP to inject DC voltage.

But this verification can wait, and the verification of the phase detector and especially the integrator are the next points.

?

I must go, come back later today.

?

De?: [email protected] <[email protected]> De la part de MattSNE via groups.io
贰苍惫辞测é?: 2 mars 2025 05:48
??: [email protected]
Objet?: Re: [HP-Agilent-Keysight-equipment] HP Agilent 8753ES VNA repair [Help]

?

Hello Yves,

?

Thank you for your last post.?

?

My VCO frequencies in TP20 are not correct. I have :

- a RF signal is at 39.100 MHz, -1.3 dBm instead of 39.840 on your board for frequency >16 MHz?

- a RF signal is at 39.280 MHz, -1.3 dBm ?for frequency <16 MHz?

?

The 2sd LO is at 977 instead of 996 this is why my sampler FI output is at 23 MHz instead of 4 KHz.

?

My VCXO is at 40.000 precisely. The VCO output to the mixer do not correctly converts the signal to L=4kHz and H=160kHz from what I measure. I have a signal at 909 KHz here.

_

?

On PIN 2 on the divider output : 39.100 MHz divide by 40 : 977 KHz. -> The 2sd LO frequency I measure. ?

?

._,_._,_

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_._,_._,_

Re: Service manual scan post processing

#150606

On Sun, 2 Mar 2025 at 16:25, Bert via <el_bert0=[email protected]> wrote:

The one thing with image cleanup routines, they are mostly made for text based documents and are looking to clean up the text. As such, they don't have the "understanding" as to the particularities of schematics.? In the way back days, there was vectorizing tools to help engineering firms convert scanned drawings, those things on dead, ground up trees to CAD files. But they required both a lot of work to verify the exactitude of the resulting CAD file and possibly re-verify and re-authorize it.

A very useful amount of cleanup can be done simply by comparing each pixel on its own to the average of the wide neighbourhood pixels. That works equally well for text and schematics, since it has no concept of either and they are both high contrast. It does not work well with photos.

How well such text/schematic cleanup works depends on the original's quality. Unsurprisingly, higher XY resolution and uniform illumination/background are advantageous, since both allow the "slicing level" to be more easily determined and more uniformly applicable.

Provided there are sufficient pixels for the text characters to be reasonably well formed (open loops, no "spurs"), OCR is then possible. Evidence: a couple of manuals I have quickly scanned on an ordinary printer/scanner/copier, post processed into TIFFs inside a PDF file, and somebody else has OCRed.

I have no comment about vectorising; I have never had any use for such a tool. I would expect it to be as (un)successful as decompiling binary object code back into a high level language source code.

Re: Service manual scan post processing

#150605

On 3/2/25 11:25, Bert via groups.io wrote:
While we seem to all agree that JPEG compression is not ideal, there ARE lossless options for TIFF and thus PDF formats.  At the museum, we use ITU-T T.6 (Group 4 FAX), which is lossless and very effective.

            -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA

Re: Manual for HP 466A amplifier

#150604

On 3/1/25 23:06, Jeremy Nichols via groups.io wrote:
Paper original will be sent to Dave McGuire on Monday.  I don't mind getting it scanned at the museum, but does it still make sense to do that after the revelation that Artek has it available?  I hadn't checked before; I had assumed the OP had already done so.

              -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA

Re: Manual for HP 466A amplifier

#150603

On 3/1/25 08:45, Jeremy Nichols via groups.io wrote:
I have a paper copy of the HP-466A manual, serial prefix 226, and could copy the schematic for you.I've got one of those amps and would like the schematic also.

-- 
John Griessen

Re: Service manual scan post processing

#150602

While we seem to all agree that JPEG compression is not ideal, there ARE lossless options for TIFF and thus PDF formats.? While yes, storage and networking and processing and scanning time is all relatively cheap, when someone is paying all that on their own dime, there are decisions to be made.

?

Where I come from, the rule for text-ish documents is 300 B&W and for image-ish it's 200 @256, and this for financial, governmental types.

?

The one thing with image cleanup routines, they are mostly made for text based documents and are looking to clean up the text. As such, they don't have the "understanding" as to the particularities of schematics.? In the way back days, there was vectorizing tools to help engineering firms convert scanned drawings, those things on dead, ground up trees to CAD files. But they required both a lot of work to verify the exactitude of the resulting CAD file and possibly re-verify and re-authorize it.?

?

The basic rule here is that you can clean up or otherwisely "alter" a document as long as the understanding does not change.

Re: HP 3403C True RMS Voltmeter display fault

#150601

On 3/2/25 09:06, factory via groups.io wrote:
The manual on the web gives type 150D for C1 & C2 on A7, these are hermetic sealed solid tants, of course they might have been replaced with a bead or the disguised bead in an axial or radial block package in the past, or HP (or someone else) might have decided to use the non-hermetic axial ones in a repair, or later build using them.  Yes, that's why I wanted to see a picture.  I've never seen the ball-of-molten-tantalum failure on anything other than a dipped unit.

And I notice they are listed as 15V parts on 12V rails, not much derating, if using non-hermetic tants make sure to use at least double the voltage rating for replacements.  Seconded.

         -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA

Re: HP 3403C True RMS Voltmeter display fault

#150600

The manual on the web gives type 150D for C1 & C2 on A7, these are hermetic sealed solid tants, of course they might have been replaced with a bead or the disguised bead in an axial or radial block package in the past, or HP (or someone else) might have decided to use the non-hermetic axial ones in a repair, or later build using them.

?

And I notice they are listed as 15V parts on 12V rails, not much derating, if using non-hermetic tants make sure to use at least double the voltage rating for replacements.

?

David

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

#150599

I don't know if this helps, but I dug out the most recent Keysight calibration certificate for this E5052A and there is a noise floor test done at 70 MHz with correlation set to 1.
I'm not sure what is involved with this test or at what power level it is run at but the numbers for the noise floor seem to be very good! I don't have anything here that can replicate this test although I could probably design a low noise LC oscillator that could get close at a 1 MHz offset.
?
I generally design wideband single loop synthesisers up at VHF through UHF and the E5052A is easily good enough for stuff like this.

?

Re: HP Agilent 8753ES VNA repair [Help]

#150597

For reference list of the component I have on the A12 board:

?

- 10H116 : Triple line receiver?

?

- LM6321: high speed buffer?

?

- MC143 : Low power RF mixer?

?

- AD7545 : CMOS multiplying DAC

?

- AD847 : AOP

?

-OP37 : AOP

?

- PH2222A: NPT transistor?

?

- TL071C: AOP

?

- 78M05 : 5V 1A LDO

?

-DG408 : CMOS multiplexer

?

-HC273A: CMOS gate flip-flop