Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- HP-Agilent-Keysight-Equipment
- Messages
Search
|
Re: General opinion on 180 series scopes?
Pete
HP 180C replaced the 180A (& I think the CRT div went up slightly, as well).
HP184A is a faster writing replacemnet for the 181A, still variable persistence w/fast write mode. The 180 series of oscilloscopes work fine, but they are a bit large & heavy for what they do. Plug-in capability is definitely a double-edged sword; I've learned to avoid connectors whenever I can. The 1740A & 1741A 'scopes provides 100MHz capability in a smaller package with better triggering. They've been selling quite cheaply on eBay (US). Manuals should be available readily for any of these. Regards, Pete Rawson |
|
Re: General opinion on 180 series scopes?
At 10:23 AM 22/01/07, you wrote:
The 1740A & 1741A 'scopes provides 100MHz capability in a smaller packageHad a 1742A for some 15 years bought from new, though first one I got from HP had a bad bow in the trace, they tried to tell me it was within spec and that +-1.0 mm is acceptable, suffice it to say I wouldnt accept it and told the finance co at the time the delivery was being rejected but HP had already rang the finance co to report it was ok without my signature !! I was really angry and threatened to publish a photo of the trace in the local paper. Within 4 hours got a ph call from HP apologising profusely and another unit with perfect straight line trace turned up about 2 weeks later from USA with freight at their expense, <chuckle> Dont think this was indicative of HP - more of the local management and fact that often in Australia we get the dregs of stuff made in Singapore under HP's trade name which doesnt pass Singapore tests, so its not shipped to USA but dumped here, happens more often than it should from other stories I have heard. After that the 1742a performed almost flawlessly for 15 years and sold it locally to a "cash converters' store for AUD$500 after it was repaired, still see some models on ebay in Oz from time to time, And yes I kept the service manual with the equipment and used it twice to look at a burned out resistor on the input stage as I recall and rewind/swap a transformer for the grid supply, Cheers Mike Massen Network Power Systems Lab +61 (0) 8 9444 8961 Mb +61 (0) 438 048961 Perth, Western Australia * USA GMC, Opel and Australian VL/VK Commodore Fuse Rail that wont warp or melt, New model V 2.0 with engine bay illumination timer and relay holder options ! * RB30 Skyline/Nissan/VL Upgraded ignition driver now in long term economy trials * Twin tyres for most sedans, trikes and motorcycle sidecars * Industrial grade PolyVinyliDeneChloride (PVDC Copolymer) in bulk, the best oxygen and water protective barrier you can find for circuit boards. * Special Equipment for sale: 60KVA 3-phase UPS with large battery cabinet - $12,000 Web site under construction, Ebay and Oztion Auctions |
|
Re: [ot] Characteristic freq of space
Its not as simple as agreeing or not as a lot of the so called first principles
are self referential or wound into self referential extensions and its nigh on impossible to avoid that, well as far as I know it hasnt yet been done. Godel was right... ie. Defining something doesnt make it true and especially so in the absence of an absolute reference, especially a non anthropic one ;) cheers mike At 07:05 AM 22/01/07, you wrote: RegardsThings like Euclids PostulatesI agree with that - the first four of Euclid's five postulates are truly Mike * GMC/VK/VL Commodore & Calais FuseRail that wont warp or melt ! * High grade VL/Skyline milspec ignition driver electronics now in development * Twin tyres for most sedans, trikes and motorcycle sidecars |
|
Re: General opinion on 180 series scopes?
Paul Jacobson
Well the last tek 465 that went on ebay here in Australia sold for the equivalent on $450US. That's out on my price range. The HP's are within my budget.
toggle quoted message
Show quoted text
And lest anyone suggest shipping a Tek from the US - the approx $300US courier charges are a bit of a show stopper, and I'm not inclined to trust regular parcel post. cheers Paul On 22/01/2007, at 10:33 AM, Richard W. Solomon wrote:
If you want a Spectrum Analyzer, get an HP. |
|
Re: General opinion on 180 series scopes?
Richard W. Solomon
If you want a Spectrum Analyzer, get an HP.
toggle quoted message
Show quoted text
If you want an oscilloscope, get a Tektronix. 73, Dick, W1KSZ -----Original Message-----
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]On Behalf Of Paul Jacobson Sent: Sunday, January 21, 2007 6:23 PM To: hp_agilent_equipment@... Subject: [hp_agilent_equipment] General opinion on 180 series scopes? In complete contrast to the discussion on the nature of scientific knowledge, I have a couple of fairly prosaic questions. I'm new to the list, and to scopes in general and I'm currently looking at buying a 180 series scope for doing basic audio work, with some digital. Digital would primarily be checking alignment of 16Mhz clock signals in an audio DAC. Will a 180 mainframe with 50Mhz plugins be up to this kind of work? Can someone give an idea of what the pro's & con's of the 180A, 180C and 184A mainframes are? thanks Paul Yahoo! Groups Links |
|
General opinion on 180 series scopes?
Paul Jacobson
In complete contrast to the discussion on the nature of scientific knowledge, I have a couple of fairly prosaic questions.
I'm new to the list, and to scopes in general and I'm currently looking at buying a 180 series scope for doing basic audio work, with some digital. Digital would primarily be checking alignment of 16Mhz clock signals in an audio DAC. Will a 180 mainframe with 50Mhz plugins be up to this kind of work? Can someone give an idea of what the pro's & con's of the 180A, 180C and 184A mainframes are? thanks Paul |
|
Re: [ot] Characteristic freq of space
Things like Euclids PostulatesI agree with that - the first four of Euclid's five postulates are truly self evident truths - definintion of a point, definition of a straight line etc. However Euclid's fifth, based on the parallelism of lines, has a fundametal problem that was finally resolved by Hilbert using hyperbolic geometry. Kepler's Laws, Newton'sOnly as far as the accuracy set by general relativity, and even that is now under scrutiny in the quest for a grand unified theory. Ohm's LawNot a done deal at the quantum level - but that remains to be established. Kirchoff's Voltage and Current LawsWhich are really a statement of the First Law of Thermodynamics (conservation of energy), which is pretty much established as a fundamental law. Maxwell's EquationsWhich again works, and can be either used with a quantised field, or adapted into general relativity. But note the above comment on grand unified theory. So I only agree in part with the list. Craig |
|
Re: General opinion on 180 series scopes?
In my experience, the HP-180 scopes are still an excellent value. They don't
use impossible-to-obtain parts; are well designed and well built. The actual bandwidth of the 180 mainframe is 100 MHz, and with the correct plug-ins will make that number. Documentation is easy to find also. Some Tektronix scopes still bring too high a price, and it may be difficult to obtain replacement parts, because they are custom-made by TEK. 50 MHz probably is OK for your application. You also might consider the HP 1740 series of scopes.You also might look at the Philips/Fluke scopes. Whatever you get, make sure that you can get the operating and service information. I currently have a 200 MHz 4 channel Philips/Fluke, a 400 MHz Tektronix and a portable Tektronix 100 MHz portable and a couple of HP scopes. Each has it best points. Stuart K6YAZ Los Angeles, CA |
|
Re: [ot] Characteristic freq of space
Robert Hagenbach
John,
Thanks. That is the best explanation I have seen so far! Bob J Forster <jfor@...> wrote: Robert Hagenbach <rc_hagenbach@...> wrote: "terms of equations from first principles" Could someone explain to me what "first principals" are? Bob Hagenbach Largo, Fl Basic truths.. sort of. Things like Euclids Postulates; Kepler's Laws, Newton's Laws; Ohm's Law Kirchoff's Voltage and Current Laws, Maxwell's Equations, among others. Basic truths that all subsequent work is based on.that are so well accepted that no further proof is required. The are assumed, tested, and essentially KNOWN to be true. -John |
|
Re: [ot] Characteristic freq of space
J Forster
Robert Hagenbach <rc_hagenbach@...> wrote:
"terms of equations from first principles" Could someone explain to me what "first principals" are? Bob Hagenbach Largo, Fl Basic truths.. sort of. Things like Euclids Postulates; Kepler's Laws, Newton's Laws; Ohm's Law Kirchoff's Voltage and Current Laws, Maxwell's Equations, among others. Basic truths that all subsequent work is based on.that are so well accepted that no further proof is required. The are assumed, tested, and essentially KNOWN to be true. -John |
|
Re: [ot] Characteristic freq of space
Robert Hagenbach
"terms of equations from first principles"
Could someone explain to me what "first principals" are? Bob Hagenbach Largo, Fl Mike <erazmus@...> wrote: Hi Guys, Apologies for the hugely off topic question but as you guys are so into RF (and its been a little quiet in last few hours ;) I was hoping someone might be able to answer a simple question, well fairly simple, with caveats no doubt... As free space has a characteristic impedance of some 376.7 Ohms (or close to)... Does free space have any (equivalent) 'characteristic' frequency or resonant frequency(s), no doubt derived from attenuation/gain factors from RF transmissions etc ? And if so, can the responder hazard a guess as to why, in terms of equations from first principles or observations from experiment, that such frequency or even such impedance exists and practical consequences thereof ? <cough> Thanks ;) Regards from Mike Massen Network Power Systems Lab +61 (0) 8 9444 8961 Mb +61 (0) 438 048961 Perth, Western Australia * USA GMC, Opel and Australian VL/VK Commodore Fuse Rail that wont warp or melt, New model V 2.0 with engine bay illumination timer and relay holder options ! * RB30 Skyline/Nissan/VL Upgraded ignition driver now in long term economy trials * Twin tyres for most sedans, trikes and motorcycle sidecars * Industrial grade PolyVinyliDeneChloride (PVDC Copolymer) in bulk, the best oxygen and water protective barrier you can find for circuit boards. * Special Equipment for sale: 60KVA 3-phase UPS with large battery cabinet - $12,000 Web site under construction, Ebay and Oztion Auctions |
|
Re: 141T variable persistence failure - fixed!
Don Collie
I would have assumed the EHT was OK if the thing worked in the conventional mode, too.
toggle quoted message
Show quoted text
What a stinker!.............................................Don. ----- Original Message -----
From: Chris van Lint To: hp_agilent_equipment@... Sent: Saturday, January 20, 2007 10:40 PM Subject: [hp_agilent_equipment] 141T variable persistence failure - fixed! Hi all, The problem has been solved. After re-checking and re-checking voltages, waveforms and magnitudes, as well as checking the integrety of crimped cables, fitting a new CRT socket, there was still no joy, with my suspicion focussing more and more on the "junction box". Well I was close........ When I could not fix the problem, I put in yet another CRT, this one also almost new. It came out of a mainframe with powersupply issues in which I had just replaced the tube. Again no joy. Back to the junction box. I decided that maybe I should find some way to check the 6.6KV post accelerator voltage from the tripler. This is not easy, as the tripler is a sealed unit and the output HT wire is moulded into the junction box, from where it is routed to the CRT. I opened the junction box and poked the HV voltage probe at the HV input and behold only about 1.1KV. I replaced the tripler, which is a real pain and time consuming, as it requires almost removing the HV power supply. I switched the gear back on and you guessed it - the variable persistence worked. When I first posted my question, I mentioned that I had not checked the 6.6KV post accelerator voltage, because that should be OK, since the unit worked fine in conventional mode. Nobody came back to me to tell me that I was wrong, wrong, wrong. This remark is not meant to be a smart a*** snipe, because I am grateful for all the suggestions and ideas. The point I am trying to make is that to engineers familar with storage CRTs, I imagine it would have been so obvious that the post accelerator HV is part of the variable persistence system, that my remark was overlooked. Not being an electronics engineer but a mere amateur (dabbler if you like), I was firmly convinced that the post accelerator HV was only involved in the conventional operating mode. I barely understand how conventional CRTs work and the variable persistence version is a complete mistery to me. Anoher lesson learned, another problem solved. Once again my thanks to all who bothered to respond. Cheers, Chris ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.2/641 - Release Date: 1/20/2007 10:24 AM |
|
Re: Diode sensors or thermocouple sensors
John Miles
That's a good point -- if you want a voltage level at your meter terminals
toggle quoted message
Show quoted text
that's proportional to power at the input of a square-law detector, you don't need to worry about the "root" part of "rms." And the integration behavior of your metering circuit takes care of the "mean" part, whether you want it to or not... -- john, KE5FX The typical domain for the diode detector is below |
|
Re: Diode sensors or thermocouple sensors
Alexander Whiplash
--- John Miles <jmiles@...> wrote:
A thermal sensor will also give true-RMS powerThe typical domain for the diode detector is below -20dBm, where the diode is operating in the "square-law" region. I believe that the response to complex waveforms is identical to the thermal converter in this case. So, for example, a pulse train with peaks of -20dBm could be accurately measured with the diode detector. However, a pulse train with peaks of -10 or 0 dbm and an average power of -20dBm would not be, unless you attenuated the signal accordingly. AW ____________________________________________________________________________________ The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. |
|
[ot] Characteristic freq of space
Hi Mike:
The characteristic impedance of free space is 120 * PI. So an antenna is just an impedance matching device from whatever impedance you start with (say 50 Ohms) to 120*PI Ohms. There are no mechanisims for reasonance in free space but there is one for the earth called the Shuman resonance. You can Google it. Something I just learned in the past couple of years is that the impedance of transmission lines is not constant for audio frequencies. For more on that see: Have Fun, Brooke Clarke, N6GCE -- w/Java w/o Java |
|
Optical fiber equipment
Thomas Fowler
Hello group--
I have two pieces of surplus equipment -- an Anritsu MW98A OTDR with 1300 nm source, and a Photodyne Optical Attenuator, 1975XQ. If you are interested in purchasing either of these, please email me off list. Thanks! -- Thomas B. Fowler, Sc.D. Senior Principal Engineer Mitretek Systems 3150 Fairview Park Drive Falls Church, VA 22042 703-610-2944 Fax 703-610-2399 tfowler@... |
|
Re: Looking for HP 117A VLF comparator data
--- In hp_agilent_equipment@..., "antoon_on6ea"
<antoon.debosschere@...> wrote: VLF comparator ?Hi I have the manual . May be I can scan and mail to you the pages you are interested in Regards Gianfranco |
to navigate to use esc to dismiss