Re: HP 3455A stability issue

#86332

I believe the creep is normal in a 3455A—the Autocal circuitry is designed to correct for the creep. The 3456A uses different circuits and doesn't creep, so it doesn't need the Autocal circuit.

I am certainly no expert and am not in front of my manuals, just going on what I remember.

Jeremy

On Fri, Oct 20, 2017 at 2:52 PM Chris Farley kc9ieq@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Show quoted text

?

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

HERE'S where it gets weird though...? 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.? When turning Auto-Cal back off again, the unit stays at 0, and starts creeping downward again. ?
Does this sound like something is faulty with the input DC amplifier, something funky with the A/D converter, or perhaps something else??? I'm a little dumbfounded by this and at a loss where to even begin. ?
OR is this perfectly normal behavior for these meters???? 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. ?

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.? Ugh. ?

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

--

4.

2225a gpib inkjet

#86331

So I’ve 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’re doing an on-site sale next weekend in Albany, N.Y. Send me a message offline and I’ll share the details.

A few pictures here: 
And that’s just the stuff that wasn’t in boxes.

Re: Looking help with HP 3322HB 110 dB programmable attenuator

#86330

I believe these are the common HP design with solenoid coils driving two plungers that switch the pads in and out. If you have not overloaded the 10 dB section, then likely the problem is with some really tiny o'rings on the plunger shafts. Once the o'rings deteriorate, the action that moves the fingers that connect to the pads does not move enough and the section goes open when asked to switch it in...

The solution is to take it apart and replace the o'rings....If the pad is bad, it will have to be replaced also.

I can do this for you if needed (for some $)

Dan in Chandler, AZ

HP 3455A stability issue

#86329

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

HERE'S where it gets weird though...? 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.? When turning Auto-Cal back off again, the unit stays at 0, and starts creeping downward again. ?
Does this sound like something is faulty with the input DC amplifier, something funky with the A/D converter, or perhaps something else??? I'm a little dumbfounded by this and at a loss where to even begin. ?
OR is this perfectly normal behavior for these meters???? 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. ?

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.? Ugh. ?

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

Looking help with HP 3322HB 110 dB programmable attenuator

#86328

Hi all,?

The HP 3322HB 110 dB programmable attenuator in my home lab 8671B 2-18 GHz Generator has developed a bad 10 dB section. Is this repairable if disassembled? Does anyone have one they'd be willing to sell?

Thanks - Kerry N6IZW in San Diego

FS: NOS in Box 20, CINCH 50-20SN-1 Connectors

#86327

开云体育

I found a box of 20 brand new in the box CINCH Model 50-20SN-1 connectors which are used in a lot of HP etc test equipment. I was able to find them on Digikey and Allied etc for about $4.50/ea.

Here is some specs:

Manufacturer:	Cinch Connectivity Solutions
RoHS:	No
Product:	With Flanges
Number of Positions:	20 Position
Pitch:	3.96 mm
Mounting Style:	Through Hole
Contact Plating:	Gold
Series:
Brand:	Cinch
Contact Material:	Spring Brass
Housing Material:	Polyester

Here is what they look like:







Asking $20 plus a small amount for shipping for all 20. PayPal or checks works fine. Thanks es 73.

Gedas, W8BYA

Gallery at 
Light travels faster than sound....
This is why some people appear bright until you hear them speak.

Re: 3586B Selective Voltmeter Help trouble shooting

#86326

>Associated circuitry in A21, A22, would also need to be verified before you conclude defective A70.

?I'm a little confused by that, if I remove A70 and close the switch and it then the unit runs a proper CAL,
?wouldn't that say A21 and A22 were good?
????????????????????? Thanks, Lamont

P.S. I'm not sure what the A70 boards does, maybe an explanation of that would help.

Re: 3586B Selective Voltmeter Help trouble shooting

#86325

The keypad switches have a leaf spring that has to buckle
in order for the switch contact to actuate.

Those that make a loud and forceful clunk have sticky grease
that is effectively gluing the leaf to the plastic parts.

If a button doesn't spring, and then suddenly release, as you
press it, it is probably defective.

As a way of visualizing what is happening, the leaf spring has
holders on each of its ends that because the spring is longer
than the space between the holders, force the spring into a
curved "L" shape up against the key plunger, and base.  When
you press the key, you are making the space even shorter, and
the spring's curve presses even tighter into the crook of the
"L".  When the key's pressure makes it so tight that the spring
cannot move any farther into the crook, the spring pops up,
making a knee, on the bottom of the "L".

If you cannot feel that happen, the spring is either missing, or
is creased.  Missing springs will usually be hanging around
somewhere in the front panel area, and can be replaced.  Bent
springs can usually be straightened by stroking the crease out
of the spring with a small stick.

Chuck Harris

nojunk@... [hp_agilent_equipment] wrote:

Show quoted text

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

Re: 3586B Selective Voltmeter Help trouble shooting

#86324

Lamont,

Associated circuitry in A21, A22, would also need to be verified before you conclude defective A70.

Dennis

--------------------------------------------

Show quoted text

On Fri, 10/20/17, nojunk@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

 Subject: [hp_agilent_equipment] Re: 3586B Selective Voltmeter Help trouble shooting
 To: hp_agilent_equipment@...
 Date: Friday, October 20, 2017, 10:34 AM

 I have an A70 board, so not a switch problem, I have
 removed, wiped doen the edge connector, it already looked
 good and reseated it. That didn't help.
 ?As a troubleshooting method can I remove the
 A70 PCB, can I close the A60S2(2) switch, then rerun the
 CAL.
 If it doesn't respond with CE-F,
 can I conclude a problem with A70?
 ????????????????????????
 Thanks, Lamont

Re: 3586B Selective Voltmeter Help trouble shooting

#86323

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

Re: 3586B Selective Voltmeter Help trouble shooting

#86322

I have an A70 board, so not a switch problem, I have removed, wiped doen the edge connector, it already looked good and reseated it. That didn't help.
?As a troubleshooting method can I remove the A70 PCB, can I close the A60S2(2) switch, then rerun the CAL.
If it doesn't respond with CE-F, can I conclude a problem with A70?
???????????????????????? Thanks, Lamont

Re: 5342A: blown sampler?

#86321

开云体育

I’ve done the connector change and, using a good quality SMA, I have two 5342As that count reliably to 26GHz and one that just won’t count reliably above about 21GHz. I don’t have a 5343A to compare to but I wonder if maybe they were just hand-selected 5342As?

73,

Steve

WB0DBS

On Oct 20, 2017, at 7:38 AM, Tobias Pluess tobias.pluess@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Show quoted text

?

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?

?

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:

?

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?

?

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?A26 and it should alternate between the two VCOs, then check A26.

To check the sampler driver A26?you really need a?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?(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?(all smd components)?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 ?and?requires short leads to minimise parasi tics.

Good luck

Greg

Re: 5342A: blown sampler?

#86320

开云体育

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

Show quoted text

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?

?

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] wrote:

?

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?

?

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?A26 and it should alternate between the two VCOs, then check A26.

To check the sampler driver A26?you really need a?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?(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?(all smd components)?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 ?and?requires short leads to minimise parasi tics.

Good luck

Greg

Re: 5342A: blown sampler?

#86319