As I said, maybe a "while longer". Why always so much controversy on here? - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Harvey White Sent: Saturday, January 8, 2022 12:25 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] HP 141T CRT Question Using a booster on a CRT is roughly equivalent to stuffing a new wick in an old candle and lighting both at the same time. Increasing the filament voltage does make the cathode hotter, but the boosters don't do this for a little bit and try to clean off the cathode surface, they just increase the voltage. Since lifetime of the filament is related to the voltage/temperature, you're shortening the life of the tube. Of course, that makes an unusable CRT useable, but for only so long. Always tradeoffs. Harvey On 1/8/2022 11:52 AM, Mike Feher wrote: It has been a long time since I had a 141T. However, I remember back
in the early 60's I worked at a Radio/TV repair shop and often had TVs
with dim video. There used to be a "booster" that would temporarily
fix the problem by increasing the filament voltage, hence the
emission. I do not know if that is feasible on the 141T design but it
may prolong the CRT's usable life a while longer if it is. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: [email protected]
<[email protected]> On Behalf Of Dave McGuire
Sent: Saturday, January 8, 2022 11:35 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 141T CRT Question
On 1/8/22 11:30 AM, WB4IUY wrote:
I have a 141T mainframe that working, OK, but I noticed if I advance
the intensity (brightness) adjustment close to max the intensity
falls back off. It doesn't go out, it just gets dimmer. Any ideas on
this before I dig into it? This is "close to" a classic symptom of a CRT with low emission. I believe the classic symptom is for the visible brightness to decrease and then increase again as the intensity control is increased. Chuck can probably explain better here.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Using a booster on a CRT is roughly equivalent to stuffing a new wick in an old candle and lighting both at the same time.
Increasing the filament voltage does make the cathode hotter, but the boosters don't do this for a little bit and try to clean off the? cathode surface, they just increase the voltage.? Since lifetime of the filament is related to the voltage/temperature, you're shortening the life of the tube.
Of course, that makes an unusable CRT useable, but for only so long.
Always tradeoffs.
Harvey
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On 1/8/2022 11:52 AM, Mike Feher wrote: It has been a long time since I had a 141T. However, I remember back in the early 60's I worked at a Radio/TV repair shop and often had TVs with dim video. There used to be a "booster" that would temporarily fix the problem by increasing the filament voltage, hence the emission. I do not know if that is feasible on the 141T design but it may prolong the CRT's usable life a while longer if it is. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Dave McGuire
Sent: Saturday, January 8, 2022 11:35 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 141T CRT Question
On 1/8/22 11:30 AM, WB4IUY wrote:
I have a 141T mainframe that working, OK, but I noticed if I advance
the intensity (brightness) adjustment close to max the intensity falls
back off. It doesn't go out, it just gets dimmer. Any ideas on this
before I dig into it? This is "close to" a classic symptom of a CRT with low emission. I believe the classic symptom is for the visible brightness to decrease and then increase again as the intensity control is increased. Chuck can probably explain better here.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
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From: [email protected] < [email protected]>
On Behalf Of Bruce via groups.io
Sent: Saturday, January 08, 2022 9:06 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP 141T CRT Question
?
Look on line - there is a piece on CRT restoration. It involves
pulsing the cathode current substantially above rated values to clean
it. It should be done carefully and ONLY after going the CRT set up
procedure to be sure the CRT bias and intensity limit are set properly.
The document is probably on this forum somewhere
FOUND IT - see attached - DO NOT try till you have done the CRT Z axis
adjustments. and if i get some time, I will forward it to you if you
cannot find it.
Cheers!
Bruce
Quoting WB4IUY <wb4iuy@...>:
> HI Dave,
>
> I remember in the days of vacuum tube HV rectifiers, this would
> happen when the rect tube was weak...but in this mostly solid state
> scope, I didn't think that would be the issue. I'll put my nose to
> the ground at swapmeets (and here!) for a spare CRT, just in case.
>
>
>
|
Look on line - there is a piece on CRT restoration. It involves pulsing the cathode current substantially above rated values to clean it. It should be done carefully and ONLY after going the CRT set up procedure to be sure the CRT bias and intensity limit are set properly.
The document is probably on this forum somewhere
FOUND IT - see attached - DO NOT try till you have done the CRT Z axis adjustments. and if i get some time, I will forward it to you if you cannot find it.
Cheers!
Bruce
Quoting WB4IUY <wb4iuy@...>:
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Show quoted text
HI Dave,
I remember in the days of vacuum tube HV rectifiers, this would happen when the rect tube was weak...but in this mostly solid state scope, I didn't think that would be the issue. I'll put my nose to the ground at swapmeets (and here!) for a spare CRT, just in case.
|
On 1/8/22 11:45 AM, WB4IUY wrote: I remember in the days of vacuum tube HV rectifiers, this would happen when the rect tube was weak...but in this mostly solid state scope, I didn't think that would be the issue. I'll put my nose to the ground at swapmeets (and here!) for a spare CRT, just in case. The emission I'm talking about is that of the CRT's cathode, not something in the power system. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
It has been a long time since I had a 141T. However, I remember back in the early 60's I worked at a Radio/TV repair shop and often had TVs with dim video. There used to be a "booster" that would temporarily fix the problem by increasing the filament voltage, hence the emission. I do not know if that is feasible on the 141T design but it may prolong the CRT's usable life a while longer if it is. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Dave McGuire Sent: Saturday, January 8, 2022 11:35 AM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] HP 141T CRT Question On 1/8/22 11:30 AM, WB4IUY wrote: I have a 141T mainframe that working, OK, but I noticed if I advance
the intensity (brightness) adjustment close to max the intensity falls
back off. It doesn't go out, it just gets dimmer. Any ideas on this
before I dig into it? This is "close to" a classic symptom of a CRT with low emission. I believe the classic symptom is for the visible brightness to decrease and then increase again as the intensity control is increased. Chuck can probably explain better here. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
HI Dave,
I remember in the days of vacuum tube HV rectifiers, this would happen when the rect tube was weak...but in this mostly solid state scope, I didn't think that would be the issue. I'll put my nose to the ground at swapmeets (and here!) for a spare CRT, just in case.
|
In search of 14XX-series Plugins for 141T
I'm in need of a Horizontal and Vertcial plug-in set for my 141T mainframe for conventional oscilloscope use. I also have a 2 sets of good spectrum analyzer plugins for the 141T for possible barter for the plug-ins I need. I have a 8552B / 8553B combo and a 8552B / 8554B combo.
Dave
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Re: HP/Agilent/Keysight version of Tek Wiki?
On 1/8/22 1:17 AM, Radu Bogdan Dicher wrote: Sorry if this was said here or elsewhere, but how does one upload images and/or PDFs to the wiki? I'm trying to build a page (HP5328A), and have original full manuals to scan (work in progress), and also pics to upload, but not sure how. It seems pretty involved from the code-like text on the page when in editing mode. It's a simple mark-up language whose aim is to be even simpler than HTML, but with increased functionality for certain types of content. This is the point of a wiki. I've tried to make it even easier by providing a template that users can simply copy to create new pages. The intention behind that was to encourage page-to-page consistency and to provide examples of the constructs in use on the site. Dokuwiki is one of the simpler wiki systems out there; there's a vast amount of information and help available online for it. As Chris pointed out, files are uploaded via the upload manager. They are then referenced in your pages. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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On 1/8/22 11:30 AM, WB4IUY wrote: I have a 141T mainframe that working, OK, but I noticed if I advance the intensity (brightness) adjustment close to max the intensity falls back off. It doesn't go out, it just gets dimmer. Any ideas on this before I dig into it? This is "close to" a classic symptom of a CRT with low emission. I believe the classic symptom is for the visible brightness to decrease and then increase again as the intensity control is increased. Chuck can probably explain better here. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
I have a 141T mainframe that working, OK, but I noticed if I advance the intensity (brightness) adjustment close to max the intensity falls back off. It doesn't go out, it just gets dimmer. Any ideas on this before I dig into it?
Thanks,
Dave
|
Re: Spaces before units (Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight version of Tek Wiki?)
On 1/8/22 10:51 AM, Toby wrote: This thread looks like it has the potential to be endless. Mods? If it starts becoming endless, I'll step in. At the moment it's relevant, as the discussion is in the context of creating a long-term archive of documentation. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Spaces before units (Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight version of Tek Wiki?)
This thread looks like it has the potential to be endless. Mods?
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Re: Spaces before units (Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight version of Tek Wiki?)
On Fri, Jan 7, 2022 at 11:17 PM, Carsten Bormann wrote:
, the basics of units and quantities for electrotechnical work have been written up by Rohde and Schwarz
Thank you ISO and R&S... but, they refer to dimensions as 'base quantities' implying to me... that if one can't put a number on 'it' then it doesn't exist. For example, when one thinks of the dimension of length, does one think of a number? I don't. I'd claim, furthermore, that to do so is limiting. Of course, this is 'philosophy.' But then, what are space counting norms: but a monitized philosophy.
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Re: Spaces before units (Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight version of Tek Wiki?)
Carsten, Ai sahport yer prahpouzd speling ruulz baht sahgdzhest dhaht dhah shwaa saund git itz oun leter radher?dhan?dhah?daigraf?"ah." Meibi '@'?
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Re: Spaces before units (Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight version of Tek Wiki?)
Ralph Waldo Emerson once wrote:" A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines. With consistency a great soul has simply nothing to do. He may as well concern himself with his shadow on the wall. Speak what you think now in hard words, and to-morrow speak what to-morrow thinks in hard words again, though it contradict every thing you said to-day. ¡ª 'Ah, so you shall be sure to be misunderstood.' ¡ª Is it so bad, then, to be misunderstood? Pythagoras was misunderstood, and Socrates, and Jesus, and Luther, and Copernicus, and Galileo, and Newton, and every pure and wise spirit that ever took flesh. To be great is to be misunderstood. A foolish consistency is the hobgoblin of little minds adored by little statesmen and philosophers and devines. With consistency a great soul has nothing to do. He may as well concern himself with his shadow on the wall." The convention of putting a space, or not putting a space, between a number and a unit is about clarity. It's your writing. If you find it more clear when you put in a space, then do that. If you find it more clear when you don't put in a space, then that is what you should do. It's your writing, and the only payment you are ever going to get for doing that writing is the pleasure of spending some of your precious little time on this earth writing... Well, that and the pleasure of being criticized because you didn't write it the way some reader wanted to read it. 99% of the time, I choose to not put a space between the number and its units, because I find the spacing of the fixed pitch typographic fonts that I prefer, to be rather wide already. Adding a space divorces the unit from the number. Further, automatic line wrapping algorithms take no heed of your desire for the number and unit to be together, and often will put those at the end of a line onto different lines. Which, rather doesn't improve the clarity of your writing. -Chuck Harris On Sat, 8 Jan 2022 08:17:10 +0100 "Carsten Bormann" <cabocabo@...> wrote: On 8. Jan 2022, at 05:40, Dave McGuire <mcguire@...> wrote:
AS / ISO 1000:1998 is the standard for display of SI units. It
says there should be a single space between the numeral and the
unit-cum-multiplier. Is that a current standard? No.
See ¡ª the ISO/IEC 80000
series has replaced most earlier standards in this space (quantities
and units).
But the rule stands.
ISO 80000-1:2009 Section 7.1.4 has this to say:
7.1.4 Expressions for quantities
The symbol of the unit shall be placed after the numerical value
in the expression for a quantity, leaving a space between the
numerical value and the unit symbol. It should be noted that this
rule also applies to the units per cent, % and per mil, ¡ë. It
should also be noted that, in accordance with this rule, the
symbol ¡ãC for the degree Celsius shall be preceded by a space when
expressing a Celsius temperature.
The only exceptions to this rule are for the units degree, minute
and second for plane angle, in which case there shall be no space
between the numerical value and the unit symbol.
Can¡¯t provide a link, because
hides
most of the document until you pay for it. (Most of ISO/IEC 80000
actually is accessible there because it is in the definitions
sections, which are not behind the paywall. But not this rule.)
If you don¡¯t want to buy tons of ISO standards, the basics of units
and quantities for electrotechnical work have been written up by
Rohde and Schwarz (who used to be the distributor of HP equipment in
Germany a few decades ago, but mostly peddles their own instruments
right now). I found this document, of all places, in their career
section; apparently you are supposed to be able to read, write,
calculate, and clearly express your units if you want to work there:
If you don¡¯t trust URL shorteners, here is the full link:
Mandatory reading.
(The specific rule that there is a space between the number and the
unit is so ingrained that isn¡¯t even spelled out as such here, but is
consistently used in the examples.)
(I don¡¯t like all these rules, just like I don¡¯t always like English
spelling very much :-) But it is the standard¡ So I don¡¯t meik ahp
mai oun ruulz.)
Gr¨¹?e, Carsten
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Re: Spaces before units (Re: [HP-Agilent-Keysight-equipment] HP/Agilent/Keysight version of Tek Wiki?)
On Fri, Jan 7, 2022 at 11:17 PM, Carsten Bormann wrote:
I don¡¯t like all these rules, just like I don¡¯t always like English spelling very much
George Orwell didn't like English spelling very much either. (I like it, as long as I have access to a spell check.) As for standards that lay out how '...quantities and units...' ought to be formatted... I blame that on some people (editors?) whose only contribution to vetting a paper is to count the spaces between the 'quantity' and the 'units.'?
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Re: HP/Agilent/Keysight version of Tek Wiki?
On Fri, Jan 7, 2022 at 10:17 PM, Radu Bogdan Dicher wrote:
and also pics to upload, but not sure how
At the top of the page, "Media Manager" takes you here: I suggest selecting the namespace for your instrument from the tree on the left (Counters in your case, I assume); then in the Upload tab after selecting your file(s), add a prefix in the textbox e.g. 5328a:test.jpg IMO that helps keep the files tidy. See for example Signal_generators:8643A:* To include those photos in the page you then use something like {{popup>:signal_generators:8643a:8643a_inside.jpg?300}} or in your case coutners:5328a:whatever.jpg
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Re: Attenuator calibration hp 54503a
i used rg-58 with bnc connectors on each end.
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Hi all,a few weeks ago i did a full recap on the psu on this hp 54503a,in the manual it states set the 5v rail to 5.2v with a 2 ohm load on the rail,at the time i didnt have suitable power resistors at 2watt,so i didnt bother,just put the psu back in the scope and did a self cal,i noticed the volt readings were about 30% off measuring the cal output from another scope,cant remember if it was high or low!,some time later i decided to look at it agine when the resistors arrived,so into a 2 ohm load the rail measured about 5.9v,i adjusted it as per service manual to 5.2v,this resulted in the readings now about 50% off,so i did a recal with the rail set correctly and it reads fine now,would doing a self cal with the rail to high of caused this error,it works fine now but just wondered,i assume on a 5v square wave signal i measure from the halfway,ie centerline point and not top to bottom ie peak to peak?
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Dave McGuire