Re: [volt-nuts] dark display for 3458
In message 5528ac6f.3030...@williams-net.com, new writes: QUESTION - will this kill the 3458 or its display somehow? Unlikely. Unfortunately it doesn't really help the display that much either, as long as the filament is powered, the wearout mechanism works, it's just faster for pixels turned on. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] dark display for 3458
Hi Poul, In my experience, there are two very significant wear mechanisms: 1) cathode emission, 2) phosphor fatigue. They seem to both run at about the same speed. -Chuck Harris Poul-Henning Kamp wrote: In message 5528ac6f.3030...@williams-net.com, new writes: QUESTION - will this kill the 3458 or its display somehow? Unlikely. Unfortunately it doesn't really help the display that much either, as long as the filament is powered, the wearout mechanism works, it's just faster for pixels turned on. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] dark display for 3458
In message 00bc01d07473$7a7344a0$6f59cde0$@gmail.com, Don@True-Cal writes: DISP? 3 (Clr) is the one in question rather is removes power to the display filament providing some help for display life. As far as I can see from my reverse engineering, it just prints a blank string. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] dark display for 3458
The 3458A DISP? command, rather entered from the front panel or via a GPIB Command is not adequately discussed in the User's Manual IMO. There are four numeric values 0,1,2 3 plus the ability to enter a string value as mentioned below. All four values are supported via the GPIB, but only 0,1 2 are valid modes for the front panel DISP? command - the front panel DISP? 3 seems to be accepted and interpreted the same as DISP? 1 (On). The value 0 (Off) seems somewhat pointless and simply places dashes across the display. The value 1 (On) is the default and normal mode. The value 2 (Msg) displays control messages only. These three modes would obviously offer no help to prolonging display life since the display filament would need to remain on. The interesting DISP? 3 (Clr) is the one in question rather is removes power to the display filament providing some help for display life. I'm not sure without actually getting inside and testing if filament voltage is present or not. Checking the schematics for a display filament voltage interrupter might also be a clue, but would still be firmware dependent. I use Agilent VEE for 3458A control and plotting and have provided a dynamic display control using DISP? 0-3 modes and I often leave the display in mode 3 (Clr) for long plot cycles (sometimes weeks). In this mode, the display is completely blank, including no enunciator (sampling) indicators at all. My hope is that the display filaments are off. Anyone know for sure? Don -Original Message- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of new Sent: Saturday, April 11, 2015 12:09 AM To: volt-nuts@febo.com Subject: [volt-nuts] dark display for 3458 Hi, again... Now that I have the keysight connection expert running my two sick 3458s, I don't need to look at data on the displays. To keep them from burning out, I wanted to turn them off. I found a workaround of: DISP 0,' (16 spaces) .' This put a period on the bottom of the blank screen and moves it 16 spaces to the right. right off the screen! So now the display is dark and only shows things like the 'err' message. QUESTION - will this kill the 3458 or its display somehow? Willy ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] dark display for 3458
From visual inspection, the filaments in these vacuu-fluroescent displays look like bare wire, which would make them some sort of doped tungsten alloy.. which doesn't really ever wear out. The only problems I have ever seen is due to phosphor fatigue. The display stops glowing on whichever digit is on all the time... and you see this as unequal brightness between the digits. I have never seen a vacuum fluorescent display just fade away in any reasonable time. They seem to go for years and years. I have alarm clocks and ovens, and microwaves with these displays some of which have been glowing for around 40 years now, and still going strong. I have seen vacuu-fluorescent displays that have gone dark, and found that the reason is the filament supply has quit...usually due to a bad electrolytic capacitor. -Chuck Harris Don@True-Cal wrote: The 3458A DISP? command, rather entered from the front panel or via a GPIB Command is not adequately discussed in the User's Manual IMO. There are four numeric values 0,1,2 3 plus the ability to enter a string value as mentioned below. All four values are supported via the GPIB, but only 0,1 2 are valid modes for the front panel DISP? command - the front panel DISP? 3 seems to be accepted and interpreted the same as DISP? 1 (On). The value 0 (Off) seems somewhat pointless and simply places dashes across the display. The value 1 (On) is the default and normal mode. The value 2 (Msg) displays control messages only. These three modes would obviously offer no help to prolonging display life since the display filament would need to remain on. The interesting DISP? 3 (Clr) is the one in question rather is removes power to the display filament providing some help for display life. I'm not sure without actually getting inside and testing if filament voltage is present or not. Checking t h e schematics for a display filament voltage interrupter might also be a clue, but would still be firmware dependent. I use Agilent VEE for 3458A control and plotting and have provided a dynamic display control using DISP? 0-3 modes and I often leave the display in mode 3 (Clr) for long plot cycles (sometimes weeks). In this mode, the display is completely blank, including no enunciator (sampling) indicators at all. My hope is that the display filaments are off. Anyone know for sure? Don -Original Message- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of new Sent: Saturday, April 11, 2015 12:09 AM To: volt-nuts@febo.com Subject: [volt-nuts] dark display for 3458 Hi, again... Now that I have the keysight connection expert running my two sick 3458s, I don't need to look at data on the displays. To keep them from burning out, I wanted to turn them off. I found a workaround of: DISP 0,' (16 spaces) .' This put a period on the bottom of the blank screen and moves it 16 spaces to the right. right off the screen! So now the display is dark and only shows things like the 'err' message. QUESTION - will this kill the 3458 or its display somehow? Willy ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
[volt-nuts] Seminar: Fundamentals of Low Current and Ultra-High Resistance Measurement
Google that and you should find a seminar sponsored by Keysight, scheduled for Tuesday, April 14, 2015 1:00pm ET / 10:00am PT (I'll convert to GMT later) Trouble is, it is streamed in a Windows format. Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
[volt-nuts] RE Tek 5111A horizontal amp problem
Solved — bad capacitor between the bases of the upper pair of cascode amplifiers on the horizontal output amp. Whew. This 5111A has a deflection HV amp board from a 5110, which certainly made troubleshooting more difficult…. Dick ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
[volt-nuts] Need help with old Tek scope
Probably a wonkey electrolytic cap... In the old TV days, this was usually caused by a coupling capacitor, not a filter capacitor. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] dark display for 3458
I have fielded two dozen pieces of equipment with 2x16 VFD from Noritake. These are on 24/7 and they were shipped over a 4 year period starting in 2000. In normal state, there are 4 digits always turned on on the first line. The other digits are rarely turned on. The displays start being noticeably darker after 2 years and barely usable after 3-4 years. The digits that are not normally used seem to last much longer but they eventually get darker, just at a much slower rate. It may be due to contamination rather than the filament itself wearing out. By now, most have been replaced at least once, with a different part number because the old one has become obsolete. Didier KO4BB On April 11, 2015 11:37:49 AM CDT, Chuck Harris cfhar...@erols.com wrote: From visual inspection, the filaments in these vacuu-fluroescent displays look like bare wire, which would make them some sort of doped tungsten alloy.. which doesn't really ever wear out. The only problems I have ever seen is due to phosphor fatigue. The display stops glowing on whichever digit is on all the time... and you see this as unequal brightness between the digits. I have never seen a vacuum fluorescent display just fade away in any reasonable time. They seem to go for years and years. I have alarm clocks and ovens, and microwaves with these displays some of which have been glowing for around 40 years now, and still going strong. I have seen vacuu-fluorescent displays that have gone dark, and found that the reason is the filament supply has quit...usually due to a bad electrolytic capacitor. -Chuck Harris Don@True-Cal wrote: The 3458A DISP? command, rather entered from the front panel or via a GPIB Command is not adequately discussed in the User's Manual IMO. There are four numeric values 0,1,2 3 plus the ability to enter a string value as mentioned below. All four values are supported via the GPIB, but only 0,1 2 are valid modes for the front panel DISP? command - the front panel DISP? 3 seems to be accepted and interpreted the same as DISP? 1 (On). The value 0 (Off) seems somewhat pointless and simply places dashes across the display. The value 1 (On) is the default and normal mode. The value 2 (Msg) displays control messages only. These three modes would obviously offer no help to prolonging display life since the display filament would need to remain on. The interesting DISP? 3 (Clr) is the one in question rather is removes power to the display filament providing some help for display life. I'm not sure without actually getting inside and testing if filament voltage is present or not. Checking t h e schematics for a display filament voltage interrupter might also be a clue, but would still be firmware dependent. I use Agilent VEE for 3458A control and plotting and have provided a dynamic display control using DISP? 0-3 modes and I often leave the display in mode 3 (Clr) for long plot cycles (sometimes weeks). In this mode, the display is completely blank, including no enunciator (sampling) indicators at all. My hope is that the display filaments are off. Anyone know for sure? Don -Original Message- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of new Sent: Saturday, April 11, 2015 12:09 AM To: volt-nuts@febo.com Subject: [volt-nuts] dark display for 3458 Hi, again... Now that I have the keysight connection expert running my two sick 3458s, I don't need to look at data on the displays. To keep them from burning out, I wanted to turn them off. I found a workaround of: DISP 0,' (16 spaces) .' This put a period on the bottom of the blank screen and moves it 16 spaces to the right. right off the screen! So now the display is dark and only shows things like the 'err' message. QUESTION - will this kill the 3458 or its display somehow? Willy ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
