On Apr 22, 2020, at 15:24, Ken Eckert <eckertkp@...> wrote:

?Hello;

Very good, that is excellent work!

Ken

?

On Mon, Apr 13, 2020 at 09:44 AM, Michael Yellin wrote:

I am parting out an HP 8594E.??Let me know what you want/need, and we can discuss pricing, or, make me an offer on the entire thing.

Hmm, I just today joined this group, and also in the last couple of days killed my cash reserves buying some HP gear; a 4140B pA meter, a 4192A? impedance analyzer, and a couple of other big heavy HP things. Shipping of which is going to be a real $train. I'm in Sydney Australia, use a reshipper in Hawthorn LA Calif.

Now I read this. How is that 8594E part-out going?
Because... I have a sick 8594E, my first ever spectrum analyzer which was bought as working last year, but wasn't.
Trouble is I don't yet know what's faulty, the repair is stalled, and I can't afford to make an offer for your entire one. Awkward timing.
The story is here:

Philipp,

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What is the clock doing/not doing.? I went looking for our manuals and it seems they did not survive the purge.

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One thing to do as a preventative measure is to look at the row of chips next to the NIXIE tubes.? In between them (I think I’ve got the position right) are resistors.? These are the current limit resistors for the NIXIEs and they get hot enough to burn the board.? We always replace them, installing about a 0.25 in above the PCA.?

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The circuit for this part is very similar to the display section of the 5327B.?

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We built a replacement clock that actually remembers who it is when the power is cycled so all of the old stuff got packed.

?

I’ll talk to my partner but I can’t find the spare boards of manuals we used to have

?

Steve

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From: [email protected] <[email protected]> On Behalf Of Philipp G
Sent: Tuesday, April 21, 2020 1:57 AM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] HP K21-5321B Digital Clock

?

Hello,

maybe anybody has a service Manual für the K21-5321B Digital Clock.

My clock dosent work the right way. I already tryed swaping ICs but i think that more than one is faulty...

Best regards from Germany

Philipp Gr?mer

Hello Tom those are switchmode related. I think you would benefit from recapping it. But as I said be carefull I one time lost connection to a middle layer and had bigger spurious. Had to trace it down. There are not many caps a few of the 180uF 3legged those can be changed to 220uF 40-50V 105 degree type.

There are a few 1000uF and a 4700uF for 5V supply. You can also try to shunt the mounted ones to find the source of the problem. In your case I would chase it as it is rather bad.

best regards Peter

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Fra: [email protected] <[email protected]> p? vegne af Tom Gardner <tggzzz@...>
Sendt: 22. april 2020 13:08
Til: [email protected] <[email protected]>
Emne: Re: [HP-Agilent-Keysight-equipment] HP8562A Errors 304,335,317,333

?

Thanks for a very fast response. The pictures are




with spurs at +-31.8kHz (-70dBc) and harmonics such as +-63.7kHz (-72dBc).

I can't remember whether those are from the cal out or a separate OCXO I "repurposed" from a scrapped MDA. In any case the results are similar, and occur at other frequencies.

Given that it is a 1989 machine with 630 hours, raised ESR is a good bet.

While I have recapped PSUs before, I don't like doing it where there are ground planes.


On 22/04/20 12:00, Peter Hansen wrote:

Hello Tom where do you see the spurs either 30khz out or around 60khz out. ??

there are 2 switch modes in use a Preregulator and a post regulator. they run 2 different voltages. Finding spurs at -70dB level can be hard. but my guess is the caps have raised ESR

best regards Peter

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Fra: [email protected] <[email protected]> p? vegne af Tom Gardner <tggzzz@...>
Sendt: 22. april 2020 12:50
Til: [email protected] <[email protected]>
Emne: Re: [HP-Agilent-Keysight-equipment] HP8562A Errors 304,335,317,333

?

I have an 8652b with spurs at -70dBc.

In your experience are there any caps which are especially at risk of failure?

I have not, yet, opened it to have a look and make measurements.

Thanks


On 22/04/20 08:46, Peter Hansen wrote:

Hello Stu be very carefull if you will recap the psu. It is an old brittle 4 layer board. solder joints does need alot of heat. You can easy ruin the connection to the middle layer. The 3 legged cap is still only a normal capacitor just with an extra leg for support. As I said before put in a 220uF cap and try it out. Do not attempt recapping anything before the problem is solved. You might end up with multiple powersupply failures. Also it is very easy to explode the main Fets in the PSU. so work carefully.

Finally I will say recapping is only due if you see spurious signals around the center response.

That can only be seen with the alulid mounted over the PSU.

The 28V is used all over in the RF circuits that is why you see errors.

So Stu why don?t you just start with changing the Cap. Use a 220uF 40-50V 105degree capacitor (no china crap)

best regards Peter

I have a 5265A but not for sale. They show up on the auction sites occasionally but seem to be scarce. The blank covers are even rarer; the only ones I’ve ever seen for sale were part of a counter for sale. I wish you success in your search, Terry.

On Tue, Apr 21, 2020 at 10:42 PM Terry Gains <terry.waihi@...> wrote:

Good Morning,

Thought I would ask on the chance that a 5265A Digital Voltmeter?plug-in might be for sale here. I plan to install the 5265A Digital Voltmeter plug-in into a K37-5245L Converter Interface which is basically a 5245L shell with just a power supply and a plug-in holder to be used as a remote source connected to the 5245L.

Also 5245?blank plug-in cover for when no plug-in installed in the 5245L would be useful if any are for sale..

Otherwise, I'm happy to keep searching the Internet.

Kind regards and stay safe,
Terry.

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Jeremy Nichols
6.