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Re: 8566B attenuator removal

 

I did actually post pictures of what I was seeing on each of the settings on another related thread message #146621.? Having now taken a second look at those pictures however, I have noticed they were indeed at 1dB/div on the vertical scale so I shall have to re-do them on 10dB/div for the sake of clarity.
Sigh... Sunday I have some time available so will remove the attenuator and inspect its internals. I may post some photos of it's innards once that's been done.
I have to say I'm becoming rather more intimately acquainted with the guts of this analyzer than I'd ever imagined!
Re: Farewell Keysight Marketing.

 

People actually intentionally want to receive email spam to begin with?
Re: Leaking alkaline cells

 

So I was obviously wrong about my comment that Zinc Carbon batteries don't leak, and I did some "research" (aka found my box of dead batteries, took some pictures, and used google translate). The super light batteries that don't leak that come with remotes I was thinking of are Manganese batteries apparently, and they are marked "DRY BATTERY" on them. It's quite possible that I've never actually seen a Zinc Carbon battery in real life, as these are the ones I always thought were Zinc Carbon. I know some people say the Zinc Carbon are marked "Heavy Duty" as this one is, and I jumped to the wrong conclusion.

battery1.jpg
battery2.jpg


On Fri, Sep 6, 2024 at 1:00?PM Adrian Godwin via <artgodwin=[email protected]> wrote:
I have a 3D maglite that was badly corroded by energisers (though, I'm not sure if UK energisers are the same as US ones). After cleaning it out iot wasn't too bad, just some roughness on the internal surface. The corrosion was in the middle and hadn't reached the switch or cap.
?
I replaced with Nicad obtained somewhere cheaply (but new, decent industrial ones, probably intended for emergency light backup). This would have resulted in dim light but I also replaced the bulb with an LED one with a switching regulator making it insensitive to low batteries. The result is pretty good.
?
Another way to get around low voltage cells is the batteriser boost regulator. They don't extend battery life anywhere near as long as claimed and aren't very useful for modern devices that can tolerate low voltage, but they will bring nicads/NiMH up to alkaline levels, useful for fussy older devices. The downside is they will try to suck every joule out of the cell - not the best way to look after rechargeables. I believe they now have a version that cuts out at NiMH end voltage.
?
For PP3s, there are some lipo-based versions with a USB C charging port. These give full 9V, unlike earlier NiMH which were low voltage (though some had 7 cells instead of 6 to compensate). I've got a couple of these lithium ones and am so far pleased with them but haven't done a long-term test.
?
Re: Free to good home, HP 5423A system + manuals and spares

 

On 9/5/24 14:01, Tam Hanna wrote:
due to ill fortune, I have an US address now.
If there are no takers and you are willing to ship domestically, let me
know.
You're based in the US now??

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
Re: FW: HP 141T NO TRACE AFTER POWER UP

 

Leroy,
?
It would be helpful to get some information to help you.? Is this symptom occurring with the plug-in installed or without?? Do you see the trace when depress the beam finder???
?
If you still have the plug-in installed (whether that be an SA or oscilloscope), I would remove it.? Confirm that the 141T is good.? Check your LV and HV voltage rails - make sure they are inspect.? You'll have to confirm all that first anyway before troubleshooting the blanking circuit.
?
Let us know what you find.
?
-Frank
Re: FW: HP 141T NO TRACE AFTER POWER UP

 

¿ªÔÆÌåÓý

Leroy,

?

The first thing I would do is check to see that all of the basic supply voltages are in spec.? Also check to see that the base line clipper is fully CCW.? I would put in the calibrator signal into the RF input and tune to about 30MHz.? Let us know what happens.

?

Mike

?

From: [email protected] <[email protected]> On Behalf Of VK5HL
Sent: Friday, September 6, 2024 11:23 AM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] FW: HP 141T NO TRACE AFTER POWER UP

?

?

?

From: vk5hl@... <vk5hl@...>
Sent: Thursday, 5 September 2024 9:02 PM
To: '[email protected]' <[email protected]>
Subject: HP 141T NO TRACE AFTER POWER UP

?

Hello All

?

I have a hp 141t when it is powered up there is no trace but when I turn off the power the trace briefly appears in top right corner.

Is it the blanking circuit or do I need to do an trace? alignment or something else. I need some guidance

?

Has anyone encountered this problem before and let me know what you did.

?

?

73's Leroy de VK5HL

?
Re: HP 5086-7906 YTO

 

¿ªÔÆÌåÓý

Hi Adri,

?

I had sent you the measurements of the RF input-output mixer signals verification, I had disassembled the High Frequency section of my 8595E to be able to provide you with this information.

If you have no more questions relating to this section, I will close my 8595E and do a flatness check to see if everything is correct.

?

Yves

?

De?: [email protected] <[email protected]> De la part de alfa beta
·¡²Ô±¹´Ç²â¨¦?: 31 ao?t 2024 12:23
??: [email protected]
Objet?: Re: [HP-Agilent-Keysight-equipment] HP 5086-7906 YTO

?

Yves,

thank you very much for all the suggestions and information with which I will continue my investigation
In the meantime I received the 2.5mm socket wrench and after?a little mod to adapt it?for the purpose (photo), I proceeded to align the spheres of the SYTF


I must say that the operation done under the microscope is quite simple

The nuts must be loosened (not too much) and with a small screwdriver that acts as a delicate lever, ?the supports of?the?spheres can be moved so that the coupling ring completely shadows them (i.e. the sphere is exactly in the center)
Removing the gold mesh was not necessary
The insertion loss has improved enormously:
at 5 GHz it is -6dBm at 6GHz it is -10dB (before the signal starting from this frequency was no longer visible) at 6.5 GHz it is only -3dB
I will install it when I have solved the problem of "blindness" in band 0 since the calibration constants that the instrument has in memory (in practice the tuning current data) are relative to the original SYTF and the "new" SYTW requires a? SYTF CAL is done

Adri

?

?
Re: FW: HP 141T NO TRACE AFTER POWER UP

 

Checked the deflection plate voltages?
Re: 8566B attenuator removal

 

Jinxie, here is my guess as to what is wrong with the attenuator. Below is part of your post from a previous thread.
?
This attenuator has three sections, 10, 20, and 40dB. Each section is either in line or it's bypassed. Various combinations of these three values will give 0-70dB in 10dB steps. Ignoring your measurements at 60 and 70dB for a moment, it looks like 50, 40, 30? and 20 are switching in and out correctly. The 10dB section is not properly bypassed in the 0dB setting. It's also not in-line in the 10dB setting. Thereffore:
?
- One or both plungers in the 10dB section are not working, likely because of one or more bad/missing o-rings.
- The solenoid logic is not working. If this attenuator has the mechanical logic, I would look at the Y-contacts.
?
You can determine if the solenoid is doing anything by listening for clicks when going between 0 and 10dB. Also listen for the type of sound when comparing the non-working 10dB section to another (working) section.
?
Regarding your 60 and 70dB observations, you don't say if you left the display in the 1dB/div setting, or if you changed to 10dB/div. You also don't say where on the screen the noise is. If you were observing with a 10/ vertical scale, and the noise was way down, then this would confirm that the path through the 10dB section is interrupted while in the 70dB setting. Similarly, if the 60dB setting shows noise near the bottom of the screen, that would imply that the path around the 10dB section is also open.
?
You can repeat these experiments by recallung reg. 8 and then changing the scale to 10dB/div. It's usually better to post pictures than to give verbal descriptions.
?
Vladan
?

At 70dB, I'm seeing just massive noise.
At 60dB, occasional noise fickers
At 50dB, I see a thick, fuzzy arch
At 40dB, I see a less fuzzy arch
At 30dB, I see a nice, clean arch
At 20dB, I see a nice clean arch of almost the same amplitude as with 30dB.
At 10dB, I see nothing
At 0dB, I again see nothing.
Re: Leaking alkaline cells

 

I have a 3D maglite that was badly corroded by energisers (though, I'm not sure if UK energisers are the same as US ones). After cleaning it out iot wasn't too bad, just some roughness on the internal surface. The corrosion was in the middle and hadn't reached the switch or cap.
?
I replaced with Nicad obtained somewhere cheaply (but new, decent industrial ones, probably intended for emergency light backup). This would have resulted in dim light but I also replaced the bulb with an LED one with a switching regulator making it insensitive to low batteries. The result is pretty good.
?
Another way to get around low voltage cells is the batteriser boost regulator. They don't extend battery life anywhere near as long as claimed and aren't very useful for modern devices that can tolerate low voltage, but they will bring nicads/NiMH up to alkaline levels, useful for fussy older devices. The downside is they will try to suck every joule out of the cell - not the best way to look after rechargeables. I believe they now have a version that cuts out at NiMH end voltage.
?
For PP3s, there are some lipo-based versions with a USB C charging port. These give full 9V, unlike earlier NiMH which were low voltage (though some had 7 cells instead of 6 to compensate). I've got a couple of these lithium ones and am so far pleased with them but haven't done a long-term test.
?
Re: Leaking alkaline cells

 

Over 400 scanned 1902-2016 issues are here:

On Fri, Sep 6, 2024 at 12:55?PM John Griessen via <john=[email protected]> wrote:
On 9/5/24 18:16, Peter Gottlieb wrote:
> Yeah but they had those neat carbon rods that could be used for other things.


Yeah, all kinds of fun experiments from Popular mechanics of the 30s 40s....
The DIY "no transformer required" carbon arc welder was my favorite read.? ?Did a mild test of it, but no steel welding.
HP 8568B from hell to Heaven... a restoration story!

 

Good evening, my name is Andrea, and I live in Florence, Italy. I want to tell you the story of the restoration of an HP 8568B spectrum analyzer that I recently purchased.
While I was searching online for spare parts for the 8568B I already own, which is in perfect working condition (it¡¯s always useful to have spare parts just in case), I came across an auction for an 8568B in Estonia. The seller was offering three available RF units, specifying that they were all incomplete, without covers, and intended for spare parts. In a separate listing, he was selling 85662A displays, also faulty, incomplete, and missing some parts. He didn¡¯t allow buyers to choose which one from the batch would be shipped.
The price was extraordinarily low, so I thought that whatever gets shipped would still exceed the value of the auction. So, I bought a display and an RF unit. About 15 days later, the courier arrived. I was horrified! The seller had wrapped everything in a single layer of very light bubble wrap and covered it with a black bag. No protection, no box.
When I opened the packages, there were loose boards inside, screws with no apparent origin, and the display unit¡¯s frame was broken. But miraculously, the CRT seemed intact...
To be continued...
Re: 8566B attenuator removal

 

¿ªÔÆÌåÓý

FWIW I had a faulty section in one of these style of attenuators, when I took it apart there was some corrosion around one of the resistor chips where it was grounded to the aluminium body, cleaned it up and it's been fine for (some years) since.
As Ozan says, dig in to it and see what you find, you may be lucky!

On 06/09/2024 19:03, Ozan wrote:

Hi Jinxie,
If 0dB attenuation was damaged because of over voltage it would have damaged a lot more. It is very likely some mechanical problem like sticky o-rings. Your phase detector repair was a lot more complex, why don't you try repairing the attenuator first? Worst case is you need a new one so nothing to lose. It may be obvious but I will mention it: Once attenuator is out can test it with a DVM by terminating to 50-ohms at DVM and applying DC voltage. Just do 20*log(Vo/Vi). This attenuator doesn't have a DC block in it so DC would work.?
Ozan
?
?
On Fri, Sep 6, 2024 at 10:14 AM, Jinxie wrote:
Hi Vladan,
?
Many thanks indeed for your observations. I was certainly aware that the Analyzer would no longer 'know' what level of attenuation was being applied to the source RF and that I would have to manually account for it, but provided that doesn't put any of the downstream circuitry at risk of damage, it's an inconvenience I may have no alternative but to live with.
This SA was owned by an RF engineer and I purchase it from him about 10 years ago along with a faulty Marconi/Aeroflex RF signal generator with a disclosed fault. No faults were disclosed in regards to the SA, however. The sig gen I was able to repair and it's a valuable item of equipment to have for all sorts of reasons. Anyway the fact that the seller disclosed the sig gen fault leads me to believe he was honest and was unaware of any issue with the SA. However, I've never done anything with that SA which could burn out the 0 and 10dB settings either, having used it solely for monitoring the RF environment around me using a short telescopic antenna, so no physical connection to the RF input.
As I mentioned, I do have an HP 8495K 0-70dB attenuator which might save the day. I don't think there are any issues with that. However, it's NOT the same type as the one in the 8566B...
Re: Leaking alkaline cells

 

On Friday 06 September 2024 12:27:03 am tgerbic wrote:
I worry about battery leakage as well and have not found a battery brand today that does not leak. I do remember some brands back in the 60s or 70s did not seem to leak but things escalated over the decades to all brands seem to leak. I think it has reached a point where companies just expect that consumers assume all batteries leak so not much consumers can do about it.

Quality in general is not really a high

With that said, I bought a bunch of old Heathkit gear filled with the old Radio Shack C batteries about 8 years ago, perhaps two dozen batteries were removed. As expected they were all dead batteries but every one was in pristine condition, almost looked clean enough to eat off of. Not even a hint of leakage. I know they were probably 20 years old but but it was almost unbelievable.? So it is possible to make non-leaking batteries but probably cost prohibitive today.
I have a 2-D-cell magliight that lives on my night table. It occurred to me recently that those batteries had been in there a *LONG* time. I picked it up and tried it out, no light, so I took the batteries out. Tested them, and they read like new. Duracell brand, marked "MAR 2013" on them. And absolutely no signs of leakage. I have had some issues with their AA cells, though.

I've tried many store brands, HF and dollar stores and others. They just don't seem to last as long as the name brand stuff in my experience. These days I buy mostly Energizers...

--
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
Re: 8566B attenuator removal

 

Hi Jinxie,
If 0dB attenuation was damaged because of over voltage it would have damaged a lot more. It is very likely some mechanical problem like sticky o-rings. Your phase detector repair was a lot more complex, why don't you try repairing the attenuator first? Worst case is you need a new one so nothing to lose. It may be obvious but I will mention it: Once attenuator is out can test it with a DVM by terminating to 50-ohms at DVM and applying DC voltage. Just do 20*log(Vo/Vi). This attenuator doesn't have a DC block in it so DC would work.?
Ozan
?
?
On Fri, Sep 6, 2024 at 10:14 AM, Jinxie wrote:

Hi Vladan,
?
Many thanks indeed for your observations. I was certainly aware that the Analyzer would no longer 'know' what level of attenuation was being applied to the source RF and that I would have to manually account for it, but provided that doesn't put any of the downstream circuitry at risk of damage, it's an inconvenience I may have no alternative but to live with.
This SA was owned by an RF engineer and I purchase it from him about 10 years ago along with a faulty Marconi/Aeroflex RF signal generator with a disclosed fault. No faults were disclosed in regards to the SA, however. The sig gen I was able to repair and it's a valuable item of equipment to have for all sorts of reasons. Anyway the fact that the seller disclosed the sig gen fault leads me to believe he was honest and was unaware of any issue with the SA. However, I've never done anything with that SA which could burn out the 0 and 10dB settings either, having used it solely for monitoring the RF environment around me using a short telescopic antenna, so no physical connection to the RF input.
As I mentioned, I do have an HP 8495K 0-70dB attenuator which might save the day. I don't think there are any issues with that. However, it's NOT the same type as the one in the 8566B...
Re: Leaking alkaline cells

 

On Thursday 05 September 2024 10:06:45 pm Dave McGuire wrote:
On 9/5/24 20:16, Peter Gottlieb wrote:
Yeah but they had those neat carbon rods that could be used for other
things.
I'm glad I wasn't the only one who did that. :)
Nope! :-)

--
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
Re: Leaking alkaline cells

 

If the equipment will allow it, then going to NiMH batteries solves the nasty leakage that many Alkaline batteries have over time. I have several pieces of audio gear that can operate with the 1.2 volt terminal potential of NiMH AA batteries so I have gone away from using the Alkaline ones. These are devices that i do not want to ever find the white crud in, as not throwaway devices. One is a Roland portable keyboard, I think it is a Go:Piano and the other is a Tascam digital 4 track recorder (Portacapture). They work OK with the lower voltage. Alkalines start with 1.5 but degrade and the voltage droops over time.
?
I have had extremely good luck with the Amazon Basics NiMH, and they are cheap. Their AA is rated for 2.4 AH.
?
You need a recharger for them, but this is so much better to me than going to the store, having white crud in months. I see that Sams Club has some Energizer brand rechargables but I didn't pay attention to what technology.
Re: Schottky Diode degradation / Replacement in instrument Sram Battery backup circuits ?

 

?
Ahh,? .... Possibly even better:
?
? Fram replacement of battery backed-up Sram, in instruments { See below } .
?
FM16W08,
?? .... battery-free !??? ( hmm ....? ~ 150yr lifetime? ? ).
?
https://www.infineon.com/dgdl/Infineon-AN100_Replacing_SRAM_with_FM1608B_FM16W08_FM1808B_or_FM18W08-ApplicationNotes-v05_00-EN.pdf?fileId=8ac78c8c7cdc391c017d073eff5862c4
?
https://cika.com/soporte/Information/Ramtron/FRAM/AppNotes/ReplaceSRAMwFRAM.pdf
?
https://www.alldatasheet.com/datasheet-pdf/download/438452/RAMTRON/FM16W08.html
?
Instrument examples,?
See:
?
?
?
?
?
?
?
rick
?
?
?
?
?
?
Re: 8566B attenuator removal

 

Hi Vladan,
?
Many thanks indeed for your observations. I was certainly aware that the Analyzer would no longer 'know' what level of attenuation was being applied to the source RF and that I would have to manually account for it, but provided that doesn't put any of the downstream circuitry at risk of damage, it's an inconvenience I may have no alternative but to live with.
This SA was owned by an RF engineer and I purchase it from him about 10 years ago along with a faulty Marconi/Aeroflex RF signal generator with a disclosed fault. No faults were disclosed in regards to the SA, however. The sig gen I was able to repair and it's a valuable item of equipment to have for all sorts of reasons. Anyway the fact that the seller disclosed the sig gen fault leads me to believe he was honest and was unaware of any issue with the SA. However, I've never done anything with that SA which could burn out the 0 and 10dB settings either, having used it solely for monitoring the RF environment around me using a short telescopic antenna, so no physical connection to the RF input.
As I mentioned, I do have an HP 8495K 0-70dB attenuator which might save the day. I don't think there are any issues with that. However, it's NOT the same type as the one in the 8566B...
Re: Leaking alkaline cells

 

I'm with Peter etc on management. Too many CxOs with large bonuses linked to short term targets. If the target is Increase sales 30% just open some new stores and reduce prices. Oh you wanted to make a profit on the sales? Sorry my contract didn't say that. If the target is increased profit just drop the quality and don't worry about the long term effect on reputation.?
It does not help that investors now want a rapid and large ROI and don't bother about the long term.
Robert.
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