听

听

听

Hi Harke,

oh, interesting. So the upgrade to 26 GHz, which would actually be a 5343A, changes only the connector? :-)
This is funny, because I use a HP 8563E spectrum analyzer at work, which operates fine at 26.5 GHz using a N connector!

Best
Tobias

---

From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Friday, October 20, 2017 14:13
To: hp_agilent_equipment@...
Subject: Re: RE: [hp_agilent_equipment] Re: 5342A: blown sampler?

听

Hello Tobias,

Congrats on the repair! Happy for you the sampler was fine! I can only comment on the frequency range. I have a number of HP equipment (including the HP5342A) that are spec'd to 20-22 GHz and with an (expensive) option that range can be extended to 26 GHz. The only hw change is the input connector that goes from N to APC3.5. No other change! Try the counter at 24 GHz and you will see it will work!

Good luck!

Harke

On Friday, October 20, 2017, 2:05:31 PM GMT+2, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

听

Hi all,

problem solved: as I said, the counter was counting fine on the low frequency input, but on the high frequency input, it displayed only zeros. The reason was that
a) the -5.2V operating voltage was out of the spec
b) the solder joint between the semirigid coax to the front panel's N connector cracked, thus the semirigid was no longer connected to the connector. I re-soldered and now it counts fine (only tested with 2 GHz so far).

I wonder whether it is possible to replace the ROM. It would be nice to add option 004, the DAC. I have couple of DAC80 here, however, opt. 004 needs a different ROM, unfortunately.

I also read that there was an option 005, which extends the frequency range to 24 GHz. Does someone know what option 005 actually was? was it a different sampler, or something that can easily be changed?

Tobias

---

From: hp_agilent_equipment@... [hp_agilent_equipment@...]
Sent: Wednesday, October 18, 2017 04:37
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Re: 5342A: blown sampler?

听

Hi,

Your measurements with the diode mode suggest the sampler is OK, digital meters don't use the same amount of current to test resistance as older analogue meters and that's the reason you didn't get their readings.

I agree with Steve, you may need to replace a number of the 1826-0371, either on the A8 main VCO, A4 offset VCO or both.

I'd also check the A5 output to see if you're getting drive to the sampler driver and then check the sampler driver A26 itself.

I'd check in that order, check the VCOs are outputting signal, check the A5 to ensure it's outputting a signal to听A26 and it should alternate between the two VCOs, then check A26.

To check the sampler driver A26听you really need a听spectrum analyser. As most spectrum analysers have a capacitor (DC block) in the front end you need to terminate the A26 module with 50 Ohm and then measure what you see ac ross that with the spec an, if you see lots of harmonics then all is good. You will not see anything听(apart from the 325MHz drive) without a dc return for the step recovery diode.

If the A26 is not working that could either be the SRD or it could be U1 on the A26 module - I have seen faulty U1 ICs in the past, most likely due to heat - they run very hot.

For the 1826-0371, you can buy fakes/replicas/copies off ebay or do what I do, I make a small smd pcb with 2 x 2sc3356 transistors, 2 x 100 ohm resistors and a 120 ohm resistor in the emitter lead听(all smd components)听with pins to fit in the DIP footprint. You'll see the schematic for the 1826-0371 on a number of the 5342A schematics. I've not had any issue with my made up boards yet.

If you find it is U1 on the A5 module I can also give you an alternative circuit for that but it is not quite optimised yet 听and听requires short leads to minimise parasi tics.

Good luck

Greg

On Oct 20, 2017, at 20:31, David Smith w6te@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Greetings,

听

I was working on an HP 438A Power Meter yesterday which was absolutely filthy inside. This thing must have been run 24/7 in a filthy environment over the years. I had to replace the fan, as usual, so I went ahead and pulled the power supply unit out to clean the dust and crap out of it. But, really, there was a layer of thick dust all over the unit.

听

This got me to thinking鈥� I need a better way of vacuuming and cleaning equipment that comes in that I won鈥檛 be fearful of damaging the cmos devices. Mind you I have a grounded ESD pad across my bench that equipment sits on when it is being worked on and I always use a grounded wrist band on my wrist. I investigated some handheld vacuum cleaners and discovered a few models that are electrostatically safe. The cost was a bit of a shocker as they sold for around $375 USD!!! (They must be very proud of their equipment.) What are the recommendations of the group for a hand held vacuum cleaner that would be safe to use around sensitive electronic equipment? I don鈥檛 mind spending $100 or so on something but $375 is a bit out of the question.

听

Best regards,

听

Dave W6TE 听

听

Sent from听听for Windows 10

听

I looked around for something similar a while back. I was thinking of the vacuums
used to clean out toner from printers (we used to have these when I worked for STK
Printer Ops). They had small nozzles and were very effective at cleaning up toner. I
wasn't able to find anything remotely affordable.

I've always wondered about using compressed air on static-sensitive electronics. It
seems to me to be a bad idea, ESD-wise, but I have no real experience.

DaveD

On 10/20/2017 9:31 PM, David Smith w6te@... [hp_agilent_equipment] wrote:

Greetings,

I was working on an HP 438A Power Meter yesterday which was absolutely filthy
inside. This thing must have been run 24/7 in a filthy environment over the years.
I had to replace the fan, as usual, so I went ahead and pulled the power supply
unit out to clean the dust and crap out of it. But, really, there was a layer of
thick dust all over the unit.

This got me to thinking鈥� I need a better way of vacuuming and cleaning equipment
that comes in that I won鈥檛 be fearful of damaging the cmos devices. Mind you I have
a grounded ESD pad across my bench that equipment sits on when it is being worked
on and I always use a grounded wrist band on my wrist. I investigated some handheld
vacuum cleaners and discovered a few models that are electrostatically safe. The
cost was a bit of a shocker as they sold for around $375 USD!!! (They must be very
proud of their equipment.) What are the recommendations of the group for a hand
held vacuum cleaner that would be safe to use around sensitive electronic
equipment? I don鈥檛 mind spending $100 or so on something but $375 is a bit out of
the question.

Best regards,

Dave W6TE

Sent from Mail <> for Windows 10

听

Greetings,

听

I was working on an HP 438A Power Meter yesterday which was absolutely filthy inside. This thing must have been run 24/7 in a filthy environment over the years. I had to replace the fan, as usual, so I went ahead and pulled the power supply unit out to clean the dust and crap out of it. But, really, there was a layer of thick dust all over the unit.

听

This got me to thinking鈥� I need a better way of vacuuming and cleaning equipment that comes in that I won鈥檛 be fearful of damaging the cmos devices. Mind you I have a grounded ESD pad across my bench that equipment sits on when it is being worked on and I always use a grounded wrist band on my wrist. I investigated some handheld vacuum cleaners and discovered a few models that are electrostatically safe. The cost was a bit of a shocker as they sold for around $375 USD!!! (They must be very proud of their equipment.) What are the recommendations of the group for a hand held vacuum cleaner that would be safe to use around sensitive electronic equipment? I don鈥檛 mind spending $100 or so on something but $375 is a bit out of the question.

听

Best regards,

听

Dave W6TE 听

听

Sent from for Windows 10

听

听

So I鈥檝e been asked to help dig out a house of a deceased electronic, test equipment and ham radio hoarder.

One of the things it turned up while going through the many many boxes was 3 HP2225 inkjet printers with Gpib interfaces.

I see the ink cartridges are still available. Has anyone tried to breathe life back into one after sitting on a shelf for a few years (decades perhaps)?

Thanks,
Bob

And yes, the place is a thing of dreams/nightmares. Floor to ceiling, basement, first, second floor, isles just wide enough to walk in. We鈥檙e doing an on-site sale next weekend in Albany, N.Y. Send me a message offline and I鈥檒l share the details.

A few pictures here:
And that鈥檚 just the stuff that wasn鈥檛 in boxes.

听

Hi All,
Have a 3455A 6.5 digit multimeter that I have finally gotten up and running after some hiccups.听 While trying to go through some of the cal procedures, I have found the unit does not stay zero'ed.听 The "Auto Cal" function seems to do its job well, that is not the issue here.听 With Auto Cal OFF and a nice shiny copper strap placed between the hi/low terminals, the unit reads .000000V in hi-accuracy mode.听 HOWEVER, that reading slowly creeps DOWNWARD in time, and have seen it as low as .000050V.听 It takes only a minute or so for the first couple uV drop.听 This also seems to happen in 2 wire resistance mode, but to a lesser extent.听 Not sure about 4 wire mode, and resolution is such that it doesn't register in ACV modes. 听

HERE'S where it gets weird though...听 If I hit Auto-Cal (or change mode/range which automatically enables Auto-Cal again) the unit reads 0 after a couple of counts, as it should, being corrected.听 When turning Auto-Cal back off again, the unit stays at 0, and starts creeping downward again. 听
Does this sound like something is faulty with the input DC amplifier, something funky with the A/D converter, or perhaps something else??听 I'm a little dumbfounded by this and at a loss where to even begin. 听
OR is this perfectly normal behavior for these meters???听 It has been on 24/7 for about a week now, so this is certainly not a matter of it not having enough time to stabilize. 听

Incidentally, this exercise has made me realize that Auto-Cal apparently does not function in my 3456A, that Simco just cal'd earlier this year.听 Ugh. 听

Any input at all with this?? 听
Regards,
Chris

I have not noticed any dead keys, but I'll run another check. I have some that click with slight force and others that work but don't click.
Thanks, Lamont