Re: General opinion on 180 series scopes?
At 11:08 AM 22/01/07, you wrote: Would a 1742A be a better option than 180series then? I've got the
opportunity to purchase one from a non-ebay source for $400AU without
probes or manuals. Does that sound like a reasonable .au price? <cough> if its the one I sold, I'd say no as I recall the hybrid for the vertical deflection was on the verge of getting erratic, that was the other reason for selling... Other than that it was a great scope as I also had the top multimeter option :) Which state are u in btw ? and is the service manual in a red 3 ring binder ? *grin* The original probes were quite good but didnt like to be kinked, the single nickel steel wire was prone to breaking in older cro probes and new probes are quite cheap now. If the vertical deflection on the cro is close to calibrated dial settings then sure its worth it, I'd probably make an offer (if it was in perth) but closer to $300 on basis that the hybrids are not replaceable any more etc. Let us know the serial number if you get it :) Rgds Mike cheers
Paul
On 22/01/2007, at 1:13 PM, Mike wrote:
At 10:23 AM 22/01/07, you wrote:
The 1740A & 1741A 'scopes provides 100MHz capability in a smaller
package
with better triggering. Had 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 Regards 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
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Re: General opinion on 180 series scopes?
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
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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 package
with better triggering. Had 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
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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: Things like Euclids Postulates I 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's
Laws Only 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 Law Not a done deal at the quantum level - but that remains to be established.
Kirchoff's Voltage and Current Laws Which are really a statement of the First Law of Thermodynamics
(conservation of energy), which is pretty much established as a fundamental
law.
Maxwell's Equations Which 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
Regards 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?
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.
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
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On 22/01/2007, at 10:33 AM, Richard W. Solomon wrote: If you want a Spectrum Analyzer, get an HP.
If you want an oscilloscope, get a Tektronix.
73, Dick, W1KSZ
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Re: General opinion on 180 series scopes?
If you want a Spectrum Analyzer, get an HP.
If you want an oscilloscope, get a Tektronix.
73, Dick, W1KSZ
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-----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
|
Hello,
What is Option HO3 on a 180A scope?
Thank you,
Bruce WA8TNC
|
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
|
Re: [ot] Characteristic freq of space
Things like Euclids Postulates I 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's
Laws Only 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 Law Not a done deal at the quantum level - but that remains to be established. Kirchoff's Voltage and Current Laws Which are really a statement of the First Law of Thermodynamics (conservation of energy), which is pretty much established as a fundamental law. Maxwell's Equations Which 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
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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
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Re: General opinion on 180 series scopes?
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Re: [ot] Characteristic freq of space
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
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Re: [ot] Characteristic freq of space
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
"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
|
hp/ moseley 3s xy recorder
i won a moseley 3s recorder on ebay and even have
a service manual coming for same.
how does one rig up a pen for it or can a standard hp xy
recorder pen be used? with some modifications
|
Re: 141T variable persistence failure - fixed!
I would have assumed the EHT was OK if the thing worked in the conventional mode, too.
What a stinker!.............................................Don.
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----- 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
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Re: Diode sensors or thermocouple sensors
That's a good point -- if you want a voltage level at your meter terminals
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
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The 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
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Re: Diode sensors or thermocouple sensors
--- John Miles <jmiles@...> wrote: A thermal sensor will also give true-RMS power
readings for all waveform
shapes, for obvious reasons, while readings taken
with a simple diode
detector will be most accurate for clean sinewaves.
The 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.
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[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
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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@...
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