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Re: USB Power Probe Calibration software
Thanks lothar for the reply.
The U8485A opt 200 sensor seems to be working very well. I think the U2001H sensor is working OK too. At least it agrees with the U8485A to <0.2 dB at 50 MHz, from +10 to -35 dBm, the 8485A's lower spec limit. At 1 GHz, it agrees similarly. I have not had a chance to test other areas yet. A E4421B is my signal source into a Weinschel 1579 precision (arm balance <.01 dB) power divider with my 2 power sensors on the output arms. I am not familiar with?DIAG:SENS:EEPROM ? X. What is the program or method that is used to send this to the sensor? |
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Re: Anybody got a good LCR meter that they want to sell?
Dr. David Kirkby (Kirkby Microwave Ltd)
On 15 Jul 2017 04:56, "dan-meeks@... [hp_agilent_equipment]" <hp_agilent_equipment@...> wrote: You really need to decide what frequency range you want. If looking at HP, you might want to consider 'impedance analysers' too.? HP seems in have this convention that impedance analysers can sweep a frequency range,? whereas LCR meters work at discrete frequencies.? My 4284A precision LCR meter measures at more than 8000 discreet frequencies from 20 Hz to 1 MHz. But the frequencies were either chosen by a disgruntled employee or mentality retarded intern! Thrre is 20 Hz, and another around 20.01 Hz, but nothing between 750 kHz and 1 MHz. At low frequencies the steps are ridiculously close together,? whereas at high frequencies they are really widely spaced.? One of the problems with HP LCR meters is the fixtures cost a fortune.? I decided to buy a new 16047A axial/radial fixture from Keysight, as the cost was lower than incomplete used ones on eBay! There's someone in Hungary selling a low cost ($50 or so) LCR meter that uses an autobalancing bridge and 4-wire Kelvin connections. This is very similar to the HP/Agilent/Keysight meters. Unlike other low cost meters, it doesn't have a switch to select L, C or R, but measures the true impedance.? I will find a link to the website if you want it. If it was not for the fact that I have the 4284A, I would buy one. Dr David Kirkby |
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Anybody got a good LCR meter that they want to sell?
Asking for a friend. Wait, not really. A friend did ask but if there is a good HP out there I may buy it and try to sell him my Leader meter. If anyone has a good LCR meter that they'd consider selling, even if it may need some TLC, please reply off-list. Thanks in advance - Dan |
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Re: 16700 software tool sets
On Fri, Jul 14, 2017 at 5:28 PM, bdallin2@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote: If you update the 16700 series system software using the "re-ignite" process of booting from the software CD it is a completely clean install from scratch. So save any configuration and data files you want to preserve before doing so. The B4600B, B4601B, and B4620B toolsets are installed as part of the standard installation during the re-ignite process. The other toolsets are on the software CD but have to be explicitly installed later. There are a few ways you can access any file on the system if denied access by the standard file permissions. You can boot in single-user mode, although that is a bit of a pain. It's easier to start up an xterm window after the system has finished booting. If I remember right that is by the <Control><Alt><Shift><F8> hotkey combination. Then you can su to root if necessary. The standard password is uh<comma>uhuh (that's a single <comma> character, not spelled out like that). If you have the system configured on a network you can also FTP and Telnet in as root to access files. I have gone through the process of installing 2.90 from scratch and modifying the license.dat file a few times myself. It's not too complicated. Do you already have a good version 2.90 software CD? -Glen |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
Hi,
I had the same problem and replaced the neon reference with zeners. This was after two sets of blown fuses and a post for help on this group.? This was back in 2012.? Then the advice was replace with zeners and a warning that the zeners do not provide the same stability as the neon. I do not remember what zeners I used; there is only the note I put in the manual "2 OCT 12 replaced neon voltage reference with zeners".? I pluralised the zener so more than one. I checked the voltage transients at turn on and was appalled at the high voltage spike; nearly 130 volts across the 82 volt reference.? Those numbers are burnt into my memory but not the number of zeners used! Little wonder the fuses blew. Lesser versions of this event must be occurring in HP 141t analysers across the planet at each turn on. Once the neon started conducting the voltage was both correct and stable. It occurred to me afterward that MAYBE I could have paralleled a slightly higher voltage zener with the tube and had the best of both worlds.? No start up spike and the stability of the neon reference. Did not try so I do not know if it would have worked, perhaps the neon tube would not have struck with the voltage limits imposed by the zeners.? Or the neon would strike but the partly conducting zeners would still introduce noise. My 141t has been working happily with this mod. Cheers Mark VK2WU |
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Re: 16700 software tool sets
Speaking of the 3 toolsets that are not found in files of the 16700A/B CD (B3760-xxx), James Laird-Wah had written that he was looking for a separate installable but that they were actually bundled in the "main depot package".
Can someone tell this dummy (not familiar with Unix) what is refered to as the "main depot package".? I am wondering if he is refering to the CD itself. I have 2.70 and would like to update it to the 2.90 but I don't want to lose the Serial tool, B4601B. Will it still be there after I update? I would also like to know how I get to and modify?? /hplogic/licensing/license.dat .? I can view it with the file tab of the session manager, but no way to change it. Thanks a bunch, guys, Bill |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
Oh dear I seem to have started something. The comment about rejuvanating neons was annecdotal refered to VR105 and the kind of neon tubes used a relaxation oscillators.
Now yes I suggested UV, and some glasses do block UVB but to quote Wikipedia (not always a reliable source :-)) Common soda lime glass is partially transparent to UVA but is opaque to shorter wavelengths, whereas fused quartz glass, depending on quality, can be transparent even to vacuum UV wavelengths. Ordinary window glass passes about 90% of the light above 350 nm, but blocks over 90% of the light below 300 nm. Bear in mind for striking you do not necessarily need "free electrons" it may be sufficient that the light reduces the work function of the metal components (or the glass) so electrons can be ripped out by the field. You do not need many electrons to strike the tube. It was offered as a "try it and see" I would be as interested as others to know if it could be useful. Alan G3NYK. |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
Ah, but alas, you need the electrons (beta particles), and they
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can't go through the glass. It is probably better to leave the incidental radium sources alone. 1/4 of us non smoking humans are going to die of cancer anyway (1/2 of the smokers), no need to up your odds higher than they already are. -Chuck Harris Artek Manuals manuals@... [hp_agilent_equipment] wrote: Go down to one of those 2nd hand store with your geiger counter and find a very old |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
[resend in case it didn't get through email]
Would you guys ease off long enough for me to type a reply? ?:) Tom,?Dave, I wish. ?But the glass stops beta. ?The Kr-85 worked?because it was?inside. Bob, Elliott, So many parts in series... sometimes brute force is the best solution, but this one puts me off. ?That's just my personal taste; if you want to do it, knock yourself out. Elliott, HP used?1% metal film resistors. ?The pot is a weak point for long-term stability, but since it's in a voltage divider the high-leg tempco compensates the low-leg tempco. ?It's also a small fraction of the total divider resistance, so its tempco is a small part of the total. In a related thread, Alan Melia suggests adding a LED to illuminate the gas tube. ?If the problem was dark effect, brought on by Kr-85 depletion, that should work around it just dandy. ?I hope someone tries it. ?I can't, my ZZ1000 is still working. ?If I can find a flickering neon at home, I'll try to figure out what wavelength LED is the most effective. ?It will be visible light, not?UV; the glass blocks UV. ?(Also external nuclear?radiation.) Dave Wise? |
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Re: Need copy/scan/borrow one page from HP 8673C/D service manual 08673-90022 or 08673-90100
¿ªÔÆÌåÓýDave,? You might see if Artek manuals has a copy. Their scans are of high quality and their prices are extremely reasonable. DaveD Sent from a small flat thingy On Jul 14, 2017, at 15:37, David Feldman wb0gaz@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
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Need copy/scan/borrow one page from HP 8673C/D service manual 08673-90022 or 08673-90100
Hello --
I'm in need of one page (8-43), a wide-format fold-out containing block diagram BD-1 from either of the above (preliminary for first printing) versions of HP service manual for 8673C/D synthesizer. The scan on keysight web site is not usable for larger-format images due to severe authoring problems (the later version of the manual 08673-90138 is even worse - they scanned double-wide tabloid form pages into letter format with very poor resolution.) If you have this manual and would be able to scan, loan or copy (or perhaps even take a series of high-resolution photos that I could stitch together) the requested page, could you drop me an e-mail off-list? Thank you very much for your assistance, Dave wb0gaz@... |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
¿ªÔÆÌåÓýWould you guys slow down long enough for me to type a reply? ?:)
Tom,?Dave,
I wish. ?But the glass stops beta. ?The Kr-85 worked?because it was?inside.
Bob, Elliott,
So many parts in series... sometimes brute force is the best solution, but this one puts me off. ?That's just my personal taste; if you want to do
it, knock yourself out.
Elliott,
HP used?1% metal film resistors. ?The pot is a weak point for long-term stability, but I think that since it's in a voltage divider the high-leg tempco compensates the low-leg tempco.
In a related thread, Alan Melia suggests adding a LED to illuminate the gas tube. ?If the problem was dark effect, brought on by Kr-85 depletion, that should work around it just
dandy. ?I hope someone tries it. ?I can't, my ZZ1000 is still working. ?If I can find a flickering neon at home, I'll try to figure out what wavelength LED is the most effective. ?It will be visible light, not?UV, the glass blocks UV, same as external nuclear?radiation.
Dave Wise?
From: hp_agilent_equipment@... <hp_agilent_equipment@...> on behalf of Tom Gardner tggzzz@... [hp_agilent_equipment]
<hp_agilent_equipment@...>
Sent: Friday, July 14, 2017 2:18 PM To: hp_agilent_equipment@... Subject: Re: [hp_agilent_equipment] Re: Replace Neon NE-2 with Zener in 141T PSU? ?
Or to a supermarket and find the "LoSalt". Replacing part of the NaCl with KCl inevitably includes K40 :)
On 14/07/17 22:15, Artek Manuals manuals@... [hp_agilent_equipment] wrote: ? |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
¿ªÔÆÌåÓýOr to a supermarket and find the
"LoSalt". Replacing part of the NaCl with KCl inevitably includes
K40 :)
On 14/07/17 22:15, Artek Manuals manuals@... [hp_agilent_equipment] wrote: ? |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
¿ªÔÆÌåÓýGo down to one of those 2nd hand store with your geiger counter and find a very old $5 watch with the glow in the dark? radium painted hands and dial. Peel of the minute hand and shrink tube it to the NE-2 :-)Dave manuals@... On 7/14/2017 5:06 PM, 'Alan Melia'
Alan.Melia@... [hp_agilent_equipment] wrote:
? -- Dave Manuals@... |
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Re: Replace Neon NE-2 with Zener in 141T PSU?
?
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The thing is that most "zeners" do not depend on
the Zener effect. That only occurs around voltages up to around 4volts, above 5v
the process is Avalanche Breakdown , a bit like a gas tube. Then the temperature
coefficient of these two processes have opposite senses so if you combine a
true?Zener with a forward diode or an avalanche diode you can minimise the
tempco.?The lowest tempcos are usually around 5 to
6v."zeners".
?
Alan
G3NYK
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Re: Replace Neon NE-2 with Zener in 141T PSU?
Bob Albert
Actually I think the lowest temperature coefficient is around 5V for zener diodes.? The 6.2 V units are very stable also so you don't need as many of those. When you put zeners in series you invoke the concern of impedance.? Low voltage zeners have a fairly high impedance compared to just a few higher voltage ones.? So if the current through it changes, so will the voltage. There are more elegant solutions to this 'problem' but the whole thread is probably more trouble than it's worth. Let us know your results. Bob On Friday, July 14, 2017 1:00 PM, "w7qed@... [hp_agilent_equipment]" wrote: Hi Dave, In theory, ~18x 4.5v zeners would provide the lowest drift reference for a pure-zener design. However, a single 82v zener has a tempo of around 0.073%. Compared to the 0.004% of the original reference bulb this is pathetic, however, looking at the dozens of carbon resistors, dried out caps, and of course the?potentiometer that sets the gain (and remember, new pots are generally not better than 100 PPM unless they are very expensive), I think the drift and tempo from a single zener will be the least of this circuit's problems!? Thanks all for your input! --E W6EL ?
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ebrucehunter