I did see a couple of previous posts from a while back, still looks like far more effort than it's worth (or is practical to do).
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Re: Racks for older equipment
The other thing that works well is the wire rack rolling carts. They will hold a lot of weight and an outlet strip fits well behind the handle. I keep the gear on a set of wire rack shelves, roll the cart over, pull off what I need for a given exercise, roll the cart back to the bench, and off I go.
On Fri, Apr 10, 2020 at 9:08 AM ArtekManuals < manuals@...> wrote: Wally
Depends on largely on
1) The size of the castors ( wheels), bigger wheels are generally easier
to deal with and actually less likely catch and tip
2) The floor surface they are rolling on
Weight? can be a factor, put? heavier on the bottom -Lighter on the top
) think low center of gravity
Though things have changed in my current set up and I have long since
abandoned the racks, you used to be able to find racks that were 36"?
high. I really like these if you have the room as the make great rolling
"table tops" with a power supply in the bottom
Dave
NR1DX
On 4/10/2020 7:09 AM, wallydoc via wrote:
> I have a bunch of old HP and other equipment and am using a Tek scope
> stand for some of it. I was wondering if anyone had any suggestions
> about rolling stands for TE, Do the rolling racks?that musicians use
> for their audio equipment work well enough? They are 19 inch racks.
> Any suggestions would be helpful.
>
> Wally KC9INK
>
--
Dave
Manuals@...
--
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I picked up a 4195A top half for peanuts from a local reseller, supposedly dead, Replace a few caps, alive. He also has the bottom sections as well as the interconnect cables. Thought I'd put together a working unit, but reading the cal procedure, needs special sw, specific HP equipment, etc. (I really hate that era where you needed some lame program to do a cal). So, is there a way to cal the beast without the original cal setup? From what I can tell, there is some magic sauce that updates the unit's earom with the cal data, can't find any refs to that. I'm thinking I should just scrap it, use the parts. Or, if someone wants it (good, bright display) locally (Southern NH), I could be persuaded.
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Forgot to mention that the HP P/N is 2100-1736.
Thanks again,
Barry - N4BUQ
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----- Original Message ----- From: "n4buq" <n4buq@...>
To: [email protected]
Sent: Friday, April 10, 2020 9:35:30 AM
Subject: [HP-Agilent-Keysight-equipment] HP 334A Balance Pots
The balance pots in my 334A have gotten pretty erratic. Am I correct to
assume these are carbon-track types and not wire-wound? I presume that this
application would demand carbon-track but in my search for a replacement,
I've seen references to wire-wound so it made me curious.
If these are carbon-track, then I'm hesitant to attempt to clean them so
wanted to confirm.
Also, if anyone knows where some good replacements are, I'd be interested.
These are 3000 ohm/100 ohm dual concentric pots.
Thanks,
Barry - N4BUQ
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The balance pots in my 334A have gotten pretty erratic. Am I correct to assume these are carbon-track types and not wire-wound? I presume that this application would demand carbon-track but in my search for a replacement, I've seen references to wire-wound so it made me curious.
If these are carbon-track, then I'm hesitant to attempt to clean them so wanted to confirm.
Also, if anyone knows where some good replacements are, I'd be interested. These are 3000 ohm/100 ohm dual concentric pots.
Thanks,
Barry - N4BUQ
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Re: Craigslist HP 8566B Indianapolis
I have a few of these units all operational and yes they are seriously heavy. This unit is nice as it appears to have the interconnect cables. It is a really nice SA. There was a flood?of units some 7 years ago and another person and told me how nice they were. Well at less then $20/section I picked up a few hoping to?make one good one. Turns out far more than 1 were operational. I had randomly picked up the interconnect cables some years before that. Just because... Good luck and I would see if you can get a slightly better deal. Regards Paul WB8TSL
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Re: Racks for older equipment
Wally
Depends on largely on
1) The size of the castors ( wheels), bigger wheels are generally easier to deal with and actually less likely catch and tip
2) The floor surface they are rolling on
Weight? can be a factor, put? heavier on the bottom -Lighter on the top ) think low center of gravity
Though things have changed in my current set up and I have long since abandoned the racks, you used to be able to find racks that were 36"? high. I really like these if you have the room as the make great rolling "table tops" with a power supply in the bottom
Dave
NR1DX
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Show quoted text
On 4/10/2020 7:09 AM, wallydoc via groups.io wrote: I have a bunch of old HP and other equipment and am using a Tek scope stand for some of it. I was wondering if anyone had any suggestions about rolling stands for TE, Do the rolling racks?that musicians use for their audio equipment work well enough? They are 19 inch racks.
Any suggestions would be helpful.
Wally KC9INK
-- Dave Manuals@... www.ArtekManuals.com
--
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Re: Seeking advice on a precision DVM
There are plenty of 34401A displays on ebay for under $30. I assume they're clones since there are so many but have no reason to think they're bad. I'm hoping the prices on 53131A displays will also continue to fall.
?
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Racks for older equipment
I have a bunch of old HP and other equipment and am using a Tek scope stand for some of it. I was wondering if anyone had any suggestions about rolling stands for TE, Do the rolling racks?that musicians use for their audio equipment work well enough? They are 19 inch racks.
Any suggestions would be helpful.
Wally KC9INK
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Re: Craigslist HP 8566B Indianapolis
Just recently, I was working on my Marconi 2380 Spectrum Analyzer and realized there was a need for a decent anti gravity device. However my inquiries to the government about their gravity wave program were not met with any degree of sincerity. Apparently they have some sort of very large device that can measure gravity "waves".
I would think the dollar value of these HP and other old test equipment units would be much higher if someone would just come up with an anti-gravity device.
Wally KC9INK
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Re: HP54603B Software Gremlins
Hi Askild,
thanks a lot for the clear and detailed pointer.
With "nonvolatile trace memory" mentioned in the manual, I thought of something
more durable (EEPROM, FlashROM) than a battery back-up SRAM :-) Would have
been nice, if the programmers had added some CRC or at least a checksum to the
data compression throwing an error message if something fails. At least they had
time for the famous "Tetris game" :-P
As the price tag for the M48Z128Y replacement from Maxim is in the $30 range,
(and then you dont't know how old it is already) I'm thinking of setting up a
"discrete" solution with a $3 128kSRAM, a coincell and 2 Schottky-Diodes
(or a DS1210).
Cheers??? Andreas
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Re: Hints on removing burned tantalum residue
So I looked up this HexaWave HWF1681RA - definitely a MESFET. If it turns out they're shot, you may be able to find NEC brand equivalents. I vaguely recall that I have some amplifiers that have NEC-something-something-8001 or 8002 types that have similar Idss specs. I don't recall the exact part numbers, but you may find a bunch searching NEC/CEL (California Eastern Laboratories - their US distributor way back when).
Ed
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Re: OT: Help identifying these mixers required - ADTEC
Hi Jeff,
Thanks for the info, very interesting.
Both devices test good on the diode range of the 34401A, next
test is to see what I can do with them
I have a Tek ext mixer on its way to me and I should be able to
put that on the 8566B and see something, I hope so anyway.
cheers
Tim
On 8/04/2020 12:56 am, Jeff Kruth via
groups.io wrote:
Tim,
The other device was
made by ADTECH as you noted, later ECI, which was bought
by Alpha Microwave (when Control Data owned them) and
became the basis for their MMW mixer line. My first boss
at Westinghouse Defense was one of the principles at ADTEC
(all came from Johns Hopkins, including Merrill Skolnik
and other notables). Really innovative MMW company in the
early 60's.
IIRC, uses a MMW flat
cartridge crystal, point contact type with a hand pointed
Tungsten whisker (using HF) made by Frank Trageser (only
guy who could do them right...).
If the diode tests good
with a ohm-meter for some sort of front to back ratio then
you are in business. Use typical precautions.? Mostly used
in the harmonic mode with LO & IF diplexed together on
the N connector, IF in the DC-several GHz (10 ?) range. If
both ends open, you can use in fundamental mode mixing. NF
ranged in the 15-20 dB area.
Should get you close.
BTW, if you decide to
get rid of the ADTEC device, let me know, would like it
for the collection.
Regards,
Jeff Kruth
In a message dated 4/7/2020 10:07:18 AM Eastern Standard Time,
Brucekareen@... writes:
Tim,
Demornai-Bonardi 633
devices were directional couplers that coupled to a
crystal detector on one coupled side and a flange on the
other.? They were generally used with a reflecting cavity
wavemeter on the flanged port to measure frequency.? The W
version would have covered 90 to 140 GHz (WR-8).? These
are fairly early designs and yours is probably at least
fifty years old.? I am not familiar with the other device.
Bruce, KG6OJI
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Re: Hints on removing burned tantalum residue
Sounds like you don't have a manual/schematic, but if you can look at the actual circuit and poke around for measurements, look for how the MESFETs are biased. If the sources are grounded, then there should be a negative gate bias supply somewhere, going into the circuit (it's also possibly generated locally, like with an ICL7660). If this bias supply is lost, the MESFETS (depletion-mode devices) will be full-on, and have very low resistance, which can be self-destructive, depending on the design. Good designs should include protection against this event, by disconnecting the drain DC supply or having some sort of intrinsic current limiting at a non-destructive level.
If the sources are degenerated and self-biased, there's no need for a negative gate bias supply. You should be able to find the source resistors and bypass caps, which will be adjacent the MESFETs, to tell if this is the case.
I'm not familiar with the parts you mentioned, but if you can find a datasheet, you can at least figure out how they should be set up. There are some enhancement-mode RF MOSFET types, but I don't know if any go to multi-GHz. I found some of these inside a power amplifier (+30 dBm 1 GHz) in my noise generator.
So anyway, measuring very low MESFET channel resistance in an unpowered circuit doesn't necessarily mean they're shot - they need to be properly biased first. If it turns out they are some kind of enhancement-mode parts, then that's a different story.
Good luck.
Ed
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SAS JBODs, was Re: [HP-Agilent-Keysight-equipment] Maximum depth of HP rack mountable gear?
On 3/30/20 12:56 AM, saipan59 (Pete) wrote: Maybe the rack was originally for HP computer systems, they had
deeper SCSI storage cabinets.
An anecdote: The last few years of my career with HP/HPE Storage, I was
the EE for a SAS-3 JBOD shelf. The main PCB is primarily a SAS expander
chip with SAS etch going to the front of the box for the drives, and to
the back of the box for the SAS cable connectors. The folks who decide
the "physical" aspects of the product insisted that the box had to be
rather deep, so that when mounted in a rack with servers, it would be a
similar depth, for ease of access to the SAS connectors and such. But
that Requirement meant that the main PCB had to be quite long, creating
signal integrity issues. As a result, we had to use an expensive PCB
material that added significant cost to the box. Nobody (of importance)
wanted to consider different cable design or chassis design options that
would have allowed a shorter board. Wow Pete, I didn't know you were involved with that stuff. Very cool. I just brought up an MSA50 not long ago, was that the model you worked on? -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Hints on removing burned tantalum residue
?
OT:? ? question? ?Aeroflex 3416 6 GHz Signal Generator,? ?No RF output? ? ?& Service Man. for 3410 - 3416 series
? ?Apologies, I will post this on the Marconi group,?
? ? ? ? but thought I might ask here, for the moment.
hi Dave, Nigel, & others who might know something about Aeroflex or its IRF /Marconi version ?
I have an Aerolflex IFR 3416 (digital) Signal Generator ?( of the 3410 Series ) that has No RF output, and I'd like to try to repair it.
a)? I fear that the RF final GaAs Mesfets are blown (dead short so far...)
They are HexaWave HWF1681RA ?or H 1681 ceramic (?), but I can not find them anywhere !
b)? Trying to find the Service & Maintenance manuals P/N: 4680/111 (or 468880/111 ?)? & P/N: 46882/500.
? ? ? ? ? ?Cobham wanted ~ $200 for the Service Man., but can't afford anything close to that.
I do have the Op Man, but that has little hardware info in it (" replace the main PCB... ").
Anyone ?
thank you,
rick
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HP 5363B Time Interval Probes & HP 8002A Pulse Gen FS
I'd like to see $US150.00 for the 5363B Time Interval Probes and $US100.00 for the 8002A Pulse Gen. Manuals for both are available.
I've had the probes for some time and they were fine the last time I used them. Not that they needed it but, puttering one evening, I pulled them apart and cleaned them, no issues were seen.
The 8002A is a U of Calgary shelf queen I've had running into a 'scope the last about week and everything responds in the expected manner.
I pack -well- and haven't a shipping issue in 20-25 years.
PayPal is good.
Best,
Bill Perkins
PEARL, Inc.
3020a Erlton St. SW
Calgary, AB
T2S 2Y6
+ 587 578 4434 Cell' and text
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Re: Seeking advice on a precision DVM
For precision nothing beats a 3458A, 8.5 digit, but it¡¯s expensive. The 3456 is the better of the 3455/3456 pair. ?Our standard bench meter is a 3478A. Should be relatively cheap and they seem to be accurate and hold cal well. Downside is a 300V max input.?
My 2 cents worth. Regards, ? Stephen Hanselman Datagate Systems, LLC
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On Apr 9, 2020, at 10:29, Daniel Koller via groups.io <kaboomdk@...> wrote:
? Hi All,
? I am wondering what sort of DVM the collective wisdom here might suggest for precision work.
? I am working on a project for work that involves designing a precision voltage controlled current source.? But due to the current pandemic, I am working from home and assembling and testing stuff in my own well equipped basement shop.? ?The current source is more or less a design out of Horowitz and Hill's "The Art of Electronics".? ?I am working to keep the full scale and linearity of this current source to within 0.1% or better.? ?
? My current best DVM is a Keithley model 173 DMM "4 and 1/2" digit, 4-wire meter (the leading digit reads to 3).? It's accurate to ~0.009%+1 digit over 24 hours on the V scales and ~0.035%+1 digit on the Ohms scales.? ?I think it's good enough for what I need, but it has a few limitations, and I am wondering if it is not time to upgrade to a real bench instrument.
? ?First of all, my DVM probably hasn't been calibrated in decades.? ?How do I know it's correct without some externally calibrated transfer standard?? ?It *may* be a possibility for me to use a meter at work (sent regularly to calibration services) and calibrate a portable voltage reference and bring it home.? ?But I don't have a resistance standard.? ?
? The other problem is that even with 4 wires on the lowest Ohms setting, I don't have enough resolution to measure a 0.100 Ohm sense resistor to within 1%.? ?
? ?So, I think I could use a better meter.? ?The HP34401A DVM seems like a nice meter to have.? It's even used as a circuit design example in H&H's text.? But they seem to go for several hundreds of $$ on e-bay.? ?Remember, this is coming out of my hobby budget.
? So, I looked at the? HP3455A / 3456A on e-bay.? These seem to be significantly cheaper, and I love vintage instruments.? BUT, do I want to take up a new project?? How reliable are these old beasts?? Are they easy to repair and calibrate?? ?What tends to go wrong with them?
? ?Even though it's more expensive, one major strong point of the HP34401A is in addition to GPIB, it's got a SERIAL interface on the back!? That is a whole different ballgame in terms of interfacing to a PC or laptop (and a whole lot easier for me, for sure).? But I do think I want to have a meter I can use, rather than one I will have to repair.? ?
? Are there any other models I am missing?? ?Are there any that come standard with an RS232 interface?? Please let me know and thank you in advance for your suggestions.
? Dan
??
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Re: Seeking advice on a precision DVM
I'd vote for the HP3455A and HP3456A. I have about three of each, and I did have to repair some of them initially (which is why they were quite cheap) - mostly the usual bad power supply cap replacement. I prefer the 3455A user interface, even though the 3456A is supposedly a little newer and better.
If you're moving from 4.5 to 6.5 digits, it will be like a breath of fresh air. You? may be able to just not worry about calibration yet, since even if old, they will likely still be much better than your old gear. During a design, you can probably get by with less than ideal equipment, and no standards to compare. For the time being, it appears you mostly need more resolution, not necessarily absolute accuracy. As you get to the end, then you can worry about the exactness.
BTW I have one old DMM that's very cool, I think, because of its exceptional resistance measurement capability. It's a DANA 5900, which at first glance is just another old 1970s lab grade DMM, with 5 digits plus 60% over-range. What's cool is that it utilizes those digits well - it includes 100 meg and 10 ohm FS ranges, which are outside those of typical DMMs. Indeed, they're out of its own auto-ranging capability, and have to be selected manually. At the high end, it tops out at 160 megs with 1 k ohm resolution. At the bottom, it can read to 16 ohms with 100 micro-ohm resolution.
I picked this up years ago at a flea market for somewhere around free to five bucks, as I recall, and it worked when I checked it out. I was considering junking it out, since it's old and beat up, and I have plenty of DMMs, until I discovered the ohms ranges. I saved it set it aside just for high megohm use. I recently had need to use it, and found it had crapped out. I've been working on it on and off over the last couple of months, trying to save it. It's almost OK now. If not for those ohms, it would be long gone.
This goes to show that even if you have good, working stuff, it can still let you down, resulting in repair or replacement projects. This will of course tend happen when you need it the most.
Anyway, I'd recommend not looking for "a" new DMM, but "some" new DMMs, if it's for a mission-critical need. I keep the HPs on the shelf in reserve or for high grade measurements, my bench DMMs are old Fluke 8400As (5+ digits), but mostly I use my pile of Harbor Freight freebie DMMs.
Ed
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Re: Craigslist HP 8566B Indianapolis
Oof!? That's a heavy one, in case somebody's not aware; 112 lbs, IIRC.? Lest you try to ship or lift one.? The display portion and the synthesizer portion do come apart, in nearly equal volume and weight halves, so that makes it a bit easier to move.? You won't want to do that often, though.
Jim Ford
------ Original Message ------
Sent: 4/9/2020 8:07:41 AM
Subject: [HP-Agilent-Keysight-equipment] Craigslist HP 8566B Indianapolis
Not mine, but I thought someone might be interested
Wally KC9INK
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bownes
Dave McGuire