I may try prying them open as well so as to be a bit more careful about how I'm cleaning things in there.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Richard Knoppow" <dickburk@...>
To: [email protected]
Sent: Friday, April 10, 2020 1:45:25 PM
Subject: Re: [HP-Agilent-Keysight-equipment] HP 334A Balance Pots
?? I have had some luck by prying the covers off for cleaning
and then crimping the tabs back. Can't be done where the pots are
stacked. AB were the best of the bunch are a pain to clean.
Ohmite sold these same pots under their own name. Same for fixed
composition resistors, Ohmite and AB are actually all AB. Ohmite
actually says this in some of its early advertising. I have no
idea what the story behind this was.
On 4/10/2020 11:30 AM, ebrucehunter via groups.io wrote:
Barry,
I have one of these instruments, but it is too buried to easily
allow inspection to determine what type of pots were used.
If the values are above 1k, they are probably not wire-wound.
If they happen to be Allen-Bradley (AB) pots, an age old remedy
is to take a 1/16-inch drill bit and drill a hole in the cover
- in the outer crevice - at the bottom of the pot away from the
terminals.? The snout of a can of contact cleaner can then be
inserted in the drilled hole to blast the interior of the pot.
This cleaning will typically last for two or three years and
then you might have to do it again.? The access hole remains
available.? In drilling the hole, metal chips seem to be pulled
outward and are unlikely to enter the pot.? But be careful so
that when the drill bit breaks through, that it does not enter
and damage the pot.
Often these pots can be cleaned by pulling outward on the shaft
-- it will move about 1/16-inch -- while quickly turning the
knob from end to end.
Bruce, KG6OJI
--
Richard Knoppow
dickburk@...
WB6KBL
|
I'd considered doing that as well but I've read horror-stories where some "cleaners" have dissolved the carbon track rather unexpectedly.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "ebrucehunter via groups.io" <Brucekareen@...>
To: [email protected]
Sent: Friday, April 10, 2020 1:30:10 PM
Subject: Re: [HP-Agilent-Keysight-equipment] HP 334A Balance Pots
Barry,
I have one of these instruments, but it is too buried to easily allow
inspection to determine what type of pots were used.
If the values are above 1k, they are probably not wire-wound.? If they happen
to be Allen-Bradley (AB) pots, an age old remedy is to take a 1/16-inch
drill bit and drill a hole in the cover - in the outer crevice - at the
bottom of the pot away from the terminals.? The snout of a can of contact
cleaner can then be inserted in the drilled hole to blast the interior of
the pot.? This cleaning will typically last for two or three years and then
you might have to do it again.? The access hole remains available.? In
drilling the hole, metal chips seem to be pulled outward and are unlikely to
enter the pot.? But be careful so that when the drill bit breaks through,
that it does not enter and damage the pot.
Often these pots can be cleaned by pulling outward on the shaft -- it will
move about 1/16-inch -- while quickly turning the knob from end to end.
Bruce, KG6OJI
|
On 4/10/20 3:16 PM, Bruce wrote: I'd like to correspond off line about how you did the translation.? I'd
like to do the same for the 8340 and some other equipment I have.? As I
said, I have an 9000/300 system and a good hpib analyzer to work with.?
I'd be interested in any insight you have developed in the process of
translating the software.? I'd be willing to share any of the HP softwar
I've collected On that note, I have calibration and verification software for many, many different instruments that I got from a calibration house that shut down. It will be awhile before I will be able to image the disks and tapes, but that is my eventual plan. They are safe for now. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
I wondered about doing something similar and have experienced what you're describing as well. Even though they're W-W, I also wondered if a ten-turn pot would work well and may give it a try (outside of the box). Of course you can't get to a balance point as quickly, it may make fine tuning somewhat easier.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Dave Wise" <david_wise@...>
To: [email protected]
Sent: Friday, April 10, 2020 2:14:29 PM
Subject: Re: [HP-Agilent-Keysight-equipment] HP 334A Balance Pots
?My 332A's COARSE pot did not respond adequately to cleaning. I replaced it.
I do not like concentric controls in this application - it's too easy for
FINE motion to nudge COARSE slightly. I drilled a hole and installed a
separate pot. I'm very satisfied with the way the controls behave, if not
how they look.
Dave Wise
________________________________
From: [email protected]
<[email protected]> on behalf of ebrucehunter via
groups.io <Brucekareen@...>
Sent: Friday, April 10, 2020 11:30 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 334A Balance Pots
Barry,
I have one of these instruments, but it is too buried to easily allow
inspection to determine what type of pots were used.
If the values are above 1k, they are probably not wire-wound. If they happen
to be Allen-Bradley (AB) pots, an age old remedy is to take a 1/16-inch
drill bit and drill a hole in the cover - in the outer crevice - at the
bottom of the pot away from the terminals. The snout of a can of contact
cleaner can then be inserted in the drilled hole to blast the interior of
the pot. This cleaning will typically last for two or three years and then
you might have to do it again. The access hole remains available. In
drilling the hole, metal chips seem to be pulled outward and are unlikely to
enter the pot. But be careful so that when the drill bit breaks through,
that it does not enter and damage the pot.
Often these pots can be cleaned by pulling outward on the shaft -- it will
move about 1/16-inch -- while quickly turning the knob from end to end.
Bruce, KG6OJI
|
Tobias -
I'd like to correspond off line about how you did the translation. I'd like to do the same for the 8340 and some other equipment I have. As I said, I have an 9000/300 system and a good hpib analyzer to work with. I'd be interested in any insight you have developed in the process of translating the software. I'd be willing to share any of the HP softwar I've collected
Cheers!
Bruce K9BC
bruce@...
Quoting Tobias Pluess <tobias.pluess@...>:
toggle quoted message
Show quoted text
Bill,
I have the cal. software ( HP BASIC). As you said, it needs a lot of specific HP gear, but I re-wrote it in Python so it can be run on a modern PC with Prologix GPIB USB adaptors. And it is possible to use it with almost any signal generators/power meters/spectrum analyzers.
Further, the 4195A does not necessarily need a full cal; if you had to replace the EEPROM, you can also just do the calibrations that need the EEPROM.
* there are AFAIR two voltage-controlled bandpass filters in the bottom unit. The EEPROM stores the tuning voltage vs. centre frequency table.
* I think there is also an ALC loop in the bottom unit; and the EEEPROM has a table of the frequency dependent output power variations.
Tobias
HB9FSX
|
?My 332A's COARSE pot?did not respond adequately to cleaning. ?I replaced it. ?I do?not like?concentric controls in this application - it's too easy for FINE motion to nudge COARSE slightly. ?I drilled a hole and installed a separate pot. ?I'm very satisfied
with the way the controls behave, if not?how they look.
Dave Wise
toggle quoted message
Show quoted text
Barry,
I have one of these instruments, but it is too buried to easily allow inspection to determine what type of pots were used.?
If the values are above 1k, they are probably not wire-wound.? If they happen to be Allen-Bradley (AB) pots, an age old remedy is to take a 1/16-inch drill bit and drill a hole in the cover - in the outer crevice - at the bottom of the pot
away from the terminals.? The snout of a can of contact cleaner can then be inserted in the drilled hole to blast the interior of the pot.? This cleaning will typically last for two or three years and then you might have to do it again.? The access hole remains
available.? In drilling the hole, metal chips seem to be pulled outward and are unlikely to enter the pot.? But be careful so that when the drill bit breaks through, that it does not enter and damage the pot.
Often these pots can be cleaned by pulling outward on the shaft -- it will move about 1/16-inch -- while quickly turning the knob from end to end.
Bruce, KG6OJI
|
On 4/10/20 2:56 PM, Tobias Pluess wrote: I have the cal. software ( HP BASIC). As you said, it needs a lot of
specific HP gear, but I re-wrote it in Python so it can be run on a
modern PC with Prologix GPIB USB adaptors. And it is possible to use it
with almost any signal generators/power meters/spectrum analyzers.
Further, the 4195A does not necessarily need a full cal; if you had to
replace the EEPROM, you can also just do the calibrations that need the
EEPROM.
* there are AFAIR two voltage-controlled bandpass filters in the bottom
unit. The EEPROM stores the tuning voltage vs. centre frequency table.
* I think there is also an ALC loop in the bottom unit; and the EEEPROM
has a table of the frequency dependent output power variations. I would really like to get a copy of both the original version and your reimplementation, if you're willing to share them. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
Excellent, I have a Prologix adapter, use it all the time. I'd
welcome a copy of your PY prog. You can privately email me: hp at
quackers dot net.
Again, thanks.
On 4/10/2020 2:56 PM, Tobias Pluess
wrote:
Bill,
I have the cal. software ( HP BASIC). As you said, it needs a lot
of specific HP gear, but I re-wrote it in Python so it can be run
on a modern PC with Prologix GPIB USB adaptors. And it is possible
to use it with almost any signal generators/power meters/spectrum
analyzers.
Further, the 4195A does not necessarily need a full cal; if you
had to replace the EEPROM, you can also just do the calibrations
that need the EEPROM.
* there are AFAIR two voltage-controlled bandpass filters in the
bottom unit. The EEPROM stores the tuning voltage vs. centre
frequency table.
* I think there is also an ALC loop in the bottom unit; and the
EEEPROM has a table of the frequency dependent output power
variations.
Tobias
HB9FSX
--
Bill Ezell
----------
I happen to know this is the Lupin Express.
|
Would you be willing to share the software (both versions)? I'm building an HP 9000/300 system and a GPIB analyzer as a platform to translate HP verification SW to more modern languages. This would be a good "test bed"
Thanks!
Bruce
Quoting Tobias Pluess <tobias.pluess@...>:
toggle quoted message
Show quoted text
Bill,
I have the cal. software ( HP BASIC). As you said, it needs a lot of specific HP gear, but I re-wrote it in Python so it can be run on a modern PC with Prologix GPIB USB adaptors. And it is possible to use it with almost any signal generators/power meters/spectrum analyzers.
Further, the 4195A does not necessarily need a full cal; if you had to replace the EEPROM, you can also just do the calibrations that need the EEPROM.
* there are AFAIR two voltage-controlled bandpass filters in the bottom unit. The EEPROM stores the tuning voltage vs. centre frequency table.
* I think there is also an ALC loop in the bottom unit; and the EEEPROM has a table of the frequency dependent output power variations.
Tobias
HB9FSX
|
Bill,
I have the cal. software ( HP BASIC). As you said, it needs a lot of specific HP gear, but I re-wrote it in Python so it can be run on a modern PC with Prologix GPIB USB adaptors. And it is possible to use it with almost any signal generators/power meters/spectrum analyzers.
Further, the 4195A does not necessarily need a full cal; if you had to replace the EEPROM, you can also just do the calibrations that need the EEPROM.
* there are AFAIR two voltage-controlled bandpass filters in the bottom unit. The EEPROM stores the tuning voltage vs. centre frequency table.
* I think there is also an ALC loop in the bottom unit; and the EEEPROM has a table of the frequency dependent output power variations.
Tobias
HB9FSX
|
Re: Racks for older equipment
On 4/10/20 2:42 PM, Paul Amaranth wrote: These are also called Metro racks and are used extensively in restaruants.
Check your local craigslist and auction sites. The commercial ones can
handle 800 lbs per shelf(!) I've found a couple of the commercial ones
for under $75. They're great for storing equipment. Yes, the "real" ones for restaurant use are NSF-rated and very, very sturdy. With lots of restaurants unfortunately going tits-up nowadays due to covid19 shutdowns, there will be a flood of commercial kitchen equipment hitting the liquidation markets soon. I found one of those carts in a dumpster once; turned into a very handy
project cart for my shop. What kind of idiot would dumpster one of those? Jeeze. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
I have had some luck by prying the covers off for cleaning and then crimping the tabs back. Can't be done where the pots are stacked. AB were the best of the bunch are a pain to clean. Ohmite sold these same pots under their own name. Same for fixed composition resistors, Ohmite and AB are actually all AB. Ohmite actually says this in some of its early advertising. I have no idea what the story behind this was.
toggle quoted message
Show quoted text
On 4/10/2020 11:30 AM, ebrucehunter via groups.io wrote: Barry,
I have one of these instruments, but it is too buried to easily allow inspection to determine what type of pots were used.
If the values are above 1k, they are probably not wire-wound.? If they happen to be Allen-Bradley (AB) pots, an age old remedy is to take a 1/16-inch drill bit and drill a hole in the cover - in the outer crevice - at the bottom of the pot away from the terminals.? The snout of a can of contact cleaner can then be inserted in the drilled hole to blast the interior of the pot.? This cleaning will typically last for two or three years and then you might have to do it again.? The access hole remains available.? In drilling the hole, metal chips seem to be pulled outward and are unlikely to enter the pot.? But be careful so that when the drill bit breaks through, that it does not enter and damage the pot.
Often these pots can be cleaned by pulling outward on the shaft -- it will move about 1/16-inch -- while quickly turning the knob from end to end.
Bruce, KG6OJI
--
Richard Knoppow
dickburk@...
WB6KBL
|
On 4/10/20 1:48 PM, Daniel Sheen wrote: I have a rather bizarre problem with a 5343A counter. Observed symptoms
are that the high frequency input works reliably up to about 250MHz,
reads garbage from around 250MHz-800MHz, and then seems to work fine
from 800MHz upward through 1GHz (I only have an 8640B handy atm so can't
really test higher than that). Cranking up the input power a bunch seems
to reduce the dead band to closer to 400MHz-600MHz.
The counter initially failed troubleshooting step 4 in the service
manual. That was resolved by replacing the A10 board (from another
counter with a blown sampler). It now passes step 5 and is marginal on
step 6 (sensitivity is a little lower than it ought to be but it seems
to work).
The one other observation I've made is the IF amplitude into and out of
A11 drops off rapidly if an input is tuned into the range of frequencies
that it's insensitive to, but I'm struggling to find a plausible
explanation for why that could occur given my understanding of the
counter design (that wouldn't also make higher frequencies not be detected).
If anyone has any thoughts or has run into this before, suggestions
would be appreciated. That almost sounds like the "suck-outs" that are typical of a damaged or loose hardline cable. I would check the input connectors and, if there's the standard SMA-terminated 0.141" hardline on the inside, look for hairline cracks around the solder joints around the connectors, or similar damage. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
Re: Racks for older equipment
These are also called Metro racks and are used extensively in restaruants.
Check your local craigslist and auction sites. The commercial ones can
handle 800 lbs per shelf(!) I've found a couple of the commercial ones
for under $75. They're great for storing equipment.
I found one of those carts in a dumpster once; turned into a very handy
project cart for my shop.
Paul
toggle quoted message
Show quoted text
On Fri, Apr 10, 2020 at 10:50:14AM -0700, wallydoc via groups.io wrote: OOPS I think the Trinity shelves/cart things are back
Is this what is being referred to??
Wally KC9INK
!DSPAM:5e90b1e1175801145720140!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows
|
Re: Racks for older equipment
I have a whole bunch of these shelving units in my house, some for books, some used as lab benchtop shelving and some used for random stuff. One can even buy plastic mats of various sizes and colors and thicknesses to sit on the shelves to solve the problem of instrument feet getting caught in the wire shelves (and to keep books from getting permanent dents from sitting on the wire shelving).
When I started looking in the home improvement stores around here for more, I found the selection in the stores to be far smaller than it was ten or fifteen years ago.
Both ULine and Global Industrial sell a wide variety of sizes, casters, extra shelves, etc.?
ULine is more expensive but has a wider selection of sizes. Global Industrial has pretty much all of the ¡°standard¡± sizes and is less expensive. The parts are interchangeable except for the plastic cones that lock the shelving to the legs, which are pairwise interchangeable only (I found this out the hard way when I moved 5 shelf units from CO to FL). I think they¡¯re all made by the same company - Nexel or Nextel, something like that
DaveD
toggle quoted message
Show quoted text
On Apr 10, 2020, at 13:47, wallydoc via < wallydoc@...> wrote: Thanks for the input by all of you.
OK I take it that rolling wire racks are a good idea, I wanted to order one or two carts from COSTCO but apparently the lower ones are not available even from the manufacturer (Trinity) right now. The higher ones are available and I have some but wanted lower ones for use in the shack. I was really hoping that this would be an option. They are more versatile than dedicated equipment racks.
I did find some 19 inch racks on Amazon for stage equipment that look good, they are about 3 feet high .
I did not open the HEIC file, I do not have the proper file viewer and don't wish to pay for one.?
Since I cannot get the lower rolling racks here is what I found:
Wally
|
Barry,
I have one of these instruments, but it is too buried to easily allow inspection to determine what type of pots were used.?
If the values are above 1k, they are probably not wire-wound.? If they happen to be Allen-Bradley (AB) pots, an age old remedy is to take a 1/16-inch drill bit and drill a hole in the cover - in the outer crevice - at the bottom of the pot away from the terminals.? The snout of a can of contact cleaner can then be inserted in the drilled hole to blast the interior of the pot.? This cleaning will typically last for two or three years and then you might have to do it again.? The access hole remains available.? In drilling the hole, metal chips seem to be pulled outward and are unlikely to enter the pot.? But be careful so that when the drill bit breaks through, that it does not enter and damage the pot.
Often these pots can be cleaned by pulling outward on the shaft -- it will move about 1/16-inch -- while quickly turning the knob from end to end.
Bruce, KG6OJI
|
Re: Craigslist HP 8566B Indianapolis
Hmmm...it took me something like eight years to find a working 8566B pair, with cables, at a reasonable (meaning what I could afford) price ($1100). That was maybe five years ago, and I¡¯ve paid attention somewhat to the prices since. I¡¯ve just never seen anything in the $20 ballpark, or $150 ballpark for that matter. It just surprised me that got one so inexpensively.
Thanks for the information.
Maybe I should renew my effort to find an inexpensive, working 8753C.
DaveD
toggle quoted message
Show quoted text
On Apr 10, 2020, at 13:30, Paul Amaranth <paul@...> wrote:
It varies considerably. I paid around $150 each for the display and SA and
then fabricated the cables. If I ran across somebody selling them for $20
a piece I would have bought a ton (probably literally). If you buy them for
"parts only" the price can go down significantly.
Considering it comes with the cables, that Craigslist price was pretty good.
If you can dicker down, it would be even better.
Had a project that required an SA a little while ago and just loved using it.
Paul
On Fri, Apr 10, 2020 at 01:20:30PM -0400, Dave Daniel wrote:
What do you mean by ¡°sections¡±? RF and display sections, or something else? I was curious so I looked on ebay and 8566Bs (with both sections) are still listed for anywhere between ~$850 and ~$2500.
DaveD
On Apr 10, 2020, at 09:15, paul swedberg <paulswedb@...> wrote:
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
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows
|
Re: Racks for older equipment
OOPS I think the Trinity shelves/cart things are back
Is this what is being referred to??
Wally KC9INK
|
Hi all, ? I have a rather bizarre problem with a 5343A counter. Observed symptoms are that the high frequency input works reliably up to about 250MHz, reads garbage from around 250MHz-800MHz, and then seems to work fine from 800MHz upward through 1GHz (I only have an 8640B handy atm so can't really test higher than that). Cranking up the input power a bunch seems to reduce the dead band to closer to 400MHz-600MHz. ? The counter initially failed troubleshooting step 4 in the service manual. That was resolved by replacing the A10 board (from another counter with a blown sampler). It now passes step 5 and is marginal on step 6 (sensitivity is a little lower than it ought to be but it seems to work). ? The one other observation I've made is the IF amplitude into and out of A11 drops off rapidly if an input is tuned into the range of frequencies that it's insensitive to, but I'm struggling to find a plausible explanation for why that could occur given my understanding of the counter design (that wouldn't also make higher frequencies not be detected). ? If anyone has any thoughts or has run into this before, suggestions would be appreciated. ? Thanks, Daniel, KC1EPN
|
Re: Racks for older equipment
Thanks for the input by all of you.
OK I take it that rolling wire racks are a good idea, I wanted to order one or two carts from COSTCO but apparently the lower ones are not available even from the manufacturer (Trinity) right now. The higher ones are available and I have some but wanted lower ones for use in the shack. I was really hoping that this would be an option. They are more versatile than dedicated equipment racks.
I did find some 19 inch racks on Amazon for stage equipment that look good, they are about 3 feet high .
I did not open the HEIC file, I do not have the proper file viewer and don't wish to pay for one.?
Since I cannot get the lower rolling racks here is what I found:
https://www.amazon.com/gp/product/B000QDRTOG/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1
Wally
|
Dave McGuire
ebrucehunter