High frequency probes use resistive, low capacitance cable and more complex compensation circuits.
What the difference between the various chinese models is I don't know.
Robert G8RPI
|
Re: Analog vs Digital Oscilloscopes
Others have explained this adequately so I will only add a voice of
agreement and some random additional thoughts.
First of all, they are fundamentally different instruments. One is
discrete while the other is continuous.
Over the years many things that undergone an analog -> digital
transition, from "old fashioned analog" to "newer, better digital".
That seems to be the root of the general affinity, especially amongst
youngsters, for digital oscilloscopes over analog ones. Digital is just
better, though they can never seem to tell you why, other than "Because
it's...DIGITAL!"
The other issue is availability. Most analog design is much harder
than most digital design (note to nit-pickers: I said MOST), and most
manufacturing of high-end analog hardware is a lot more expensive than
most manufacturing of high-end digital hardware. This has led
manufacturers to prefer to make and sell digital oscilloscopes over
analog ones. Digital oscilloscopes are a lot cheaper to design and
make, especially in China where manufacturing volume far exceeds
engineering talent.
One other issue, though in which direction the causality relationship
goes is debatable, is the demise of CRTs. CRTs are inherently
continuous devices, while LCDs (and most other flat-screen display
technologies) are inherently digital, or discrete, devices.
So, let's face it, graphing voltage against time is a process that was
essentially perfected a long time ago. The only thing we're really
optimizing for anymore in successive generations of oscilloscopes is
whiz-bang features (and we're running out of ideas for those) and profit
margins. Sure, there are ever-faster 50+GHz instruments, but those are
for very specialized applications that almost nobody actually uses, in
comparison to the rest of us...but in general, an oscilloscope made last
month does pretty much the same thing as an oscilloscope made twenty
years ago.
For a long while I've been at the point where I can put pretty much
any oscilloscope I want on my bench. I own probably thirty
oscilloscopes now (I have a "thing" for oscilloscopes!), but I regularly
use three on my "ordinary day-to-day work" bench: A Tek 2465A, a Tek
7854 with various plugins, and a Tek TDS3012. Which do I prefer? None!
I use the best tool for the job at hand, on a task-by-task basis.
Knowing the strengths, weaknesses, and capabilities of each of your
instruments is the key.
-Dave
toggle quoted message
Show quoted text
On 07/20/2017 10:33 AM, bunge@... [hp_agilent_equipment] wrote:
Do digital 'scopes replace analog ones?
Perhaps this has been covered in which case I apologise.
I have a Tek 2467B and two of my friends have Tek 2465 'scopes, one of
which has a failed horizontal chip (see the Tek site). There do not
appear to be analog replacements for these 'scopes. I looked through HP
and Tek catalogs into the mid 1990's and see that HP dropped analog
'scopes completely and Tek does not show a replacement for the 2467B.
My experience in 1990 with a DSO was frustrating and, even knowing what
was there, I could not get a fast pulse pair to show on the DSO. It
showed sine waves. My HP54540 will display a fast pulse pair easily with
no confusion, so they have improved.
My question is if there is still a place for an analog 'scope? I use
mine all the time but I am obsolete.
If a digital 'scope will replace the Tek 2467B then which one would be a
good choice? What are people using t hese days and is there anything
affordable from the late 1990's?
Has anyone successfully replaced the horizontal chip on a Tek 2465/67
with a DIY board?
Has anyone got the Thomas Lafay PCB working? I will ask on the Tek site
as well.
--
Dave McGuire, AK4HZ
New Kensington, PA
|
I am confused regarding the stated bandwidth of an oscilloscope probe. I thought that the bandwidth was computed from the input impedance, almost purely capacitive at high frequencies. as the frequency where the reactance drops to 50 Ohms. This idea seems to work most of the time but I am seeing some probes with stated bandwidth somewhat higher.? For instance I see some Chinese probes advertised as 100 MHz, 200 MHz, even higher, yet their input capacitance is still around 20 pF more or less. Before you jump down my throat about how terrible Chinese stuff is, let's keep it at a technical level and explain just what bandwidth means so I can decide what to buy. I see probes very cheap (not really rugged but still a good value) for various prices from around $4 to $13 but they appear to be the same, except for the bandwidth rating.? How can this be? Since my use is very casual and I don't need to pay for high quality, this is a somewhat important question.? And of course, after a few years they fall apart and I need to purchase again, but over my lifetime I don't usually get to where I have spent the same money as for a Tek or HP probe. Bob
|
Re: OT: Anyone in UK (or Europe) likely to be placing an order with Lemo in the near future
toggle quoted message
Show quoted text
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: 20 July 2017 12:21
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Re: OT: Anyone in UK (or Europe) likely to be placing an order with Lemo in the near future? ?? requesting a sample.
|
Re: Analog vs Digital Oscilloscopes
Harvey gave you an excellent summary that answers
all your questions. I was typing up a reply when I saw Harvey's
response come in so I canned mine. I would like to add one
little tid-bit.... back in my prior life when I worked in the
lab where we did specialized measurements an analog scope was if
fact a huge asset. It may seem funny that even at a modern and
large aerospace corporation lab that is filled with millions of
dollars worth of the latest digital gear we still had a handful
of maintained & calibrated 7000 series (and other) analog
scopes ! Digital scopes because of their sampling & alias
issues can at times have a hissy fit when you try to properly
display a low frequency signal at the same time you are looking
at a high frequency signal. Analog scopes are much more capable
of doing this and were of great value to us.
Gedas, W8BYA
Gallery at
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 7/20/2017 10:33 AM, bunge@...
[hp_agilent_equipment] wrote:
toggle quoted message
Show quoted text
?
Do digital 'scopes replace analog ones?
Perhaps this has been covered in which case I
apologise.
I have a Tek 2467B and two of my friends have Tek 2465
'scopes, one of which has a failed horizontal chip (see
the Tek site). There do not appear to be analog
replacements for these 'scopes. I looked through HP and
Tek catalogs into the mid 1990's and see that HP dropped
analog 'scopes completely and Tek does not show a
replacement for the 2467B.
My experience in 1990 with a DSO was frustrating and,
even knowing what was there, I could not get a fast pulse
pair to show on the DSO. It showed sine waves. My HP54540
will display a fast pulse pair easily with no confusion,
so they have improved.
My question is if there is still a place for an analog
'scope? I use mine all the time but I am obsolete.
If a digital 'scope will replace the Tek 2467B then which
one would be a good choice? What are peopl e using these
days and is there anything affordable from the late
1990's?
Has anyone successfully replaced the horizontal chip
on a Tek 2465/67 with a DIY board?
Has anyone got
the Thomas Lafay PCB working? I will ask on the Tek
site as well.
|
Re: Analog vs Digital Oscilloscopes
On 20 Jul 2017 14:33:12 +0000, you wrote: Do digital 'scopes replace analog ones? nope. Perhaps this has been covered in which case I apologise.
I have a Tek 2467B and two of my friends have Tek 2465 'scopes, one of which has a failed horizontal chip (see the Tek site). There do not appear to be analog replacements for these 'scopes. I looked through HP and Tek catalogs into the mid 1990's and see that HP dropped analog 'scopes completely and Tek does not show a replacement for the 2467B. Not surprising. Digital is easier (in a way) to manufacture, offers more bells and whistles and has better connectivity. My experience in 1990 with a DSO was frustrating and, even knowing what was there, I could not get a fast pulse pair to show on the DSO. It showed sine waves. My HP54540 will display a fast pulse pair easily with no confusion, so they have improved.
My question is if there is still a place for an analog 'scope? I use mine all the time but I am obsolete. Er... no, you aren't. You've just specialized in older equipment... Digital scopes are sampling scopes, they take a bit of data, rest, take a bit more. What happens between those data samples the scope has no idea, nor can it. Only if a sample happens exactly on something interesting can you see it. Lower frequency repetitive events have the samples jitter (one way to do it) so that they get just about everything. On a single pulse mode, the sampling has to be fast enough to get that pulse reasonably, and at a single try. Analog scopes don't have this problem. I have both. I use both. For low frequency single events (like 50 Mhz or so, I use a 500 Mhz digital scope, or if the rep rate is low, same scope. For looking at high frequency events, some rise times, things above 50 Mhz or so, or if I need some odd plugin that my digital scope won't do, then it's a Tek 7000 with a set of plugins. That goes to 500 Mhz and gracefully dies off in response. The digital scopes have a sharper cutoff to avoid aliasing. If a digital 'scope will replace the Tek 2467B then which one would be a good choice? What are people using these days and is there anything affordable from the late 1990's? If you can, you might want to try the 7000 series, generally a 7904 or a 7904A; both analog. Avoid the 7104 because of the specialized CRT, which has a limited life (although it does have a 1 GHz bandwidth with the right plugins). You might want to check out the Tek TDS 800 (possibly 700) series. The 500 series (which I have, 540A) needs recapping at some point in its life. Ditto I think for the TDS 600 series. Look for reviews on these to find specific weak points. Has anyone successfully replaced the horizontal chip on a Tek 2465/67 with a DIY board?
Has anyone got the Thomas Lafay PCB working? I will ask on the Tek site as well.
Don't have a 2465. Harvey
|
Analog vs Digital Oscilloscopes
Do digital 'scopes replace analog ones? Perhaps this has been covered in which case I apologise. I have a Tek 2467B and two of my friends have Tek 2465 'scopes, one of which has a failed horizontal chip (see the Tek site). There do not appear to be analog replacements for these 'scopes. I looked through HP and Tek catalogs into the mid 1990's and see that HP dropped analog 'scopes completely and Tek does not show a replacement for the 2467B. My experience in 1990 with a DSO was frustrating and, even knowing what was there, I could not get a fast pulse pair to show on the DSO. It showed sine waves. My HP54540 will display a fast pulse pair easily with no confusion, so they have improved. My question is if there is still a place for an analog 'scope? I use mine all the time but I am obsolete. If a digital 'scope will replace the Tek 2467B then which one would be a good choice? What are people using these days and is there anything affordable from the late 1990's?
Has anyone successfully replaced the horizontal chip on a Tek 2465/67 with a DIY board? Has anyone got the Thomas Lafay PCB working? I will ask on the Tek site as well.
|
Re: H'P606A, 606B Question
Yes, I have a plastic squeeze bottle of it with a needle applicator. Works great.
I wonder, though, on the 606 problems that it could be something besides poor contacts and breaking/making that switch causes the oscillator to "restart".
When you rotate it to start it, does it eventually drop out again?
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "'James R. Bartlett' james.r.bart@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
To: "hp agilent equipment" <hp_agilent_equipment@...>
Sent: Thursday, July 20, 2017 5:52:18 AM
Subject: Re: [hp_agilent_equipment] Re: H'P606A, 606B Question
De oxit is available in non spray form, Comes in a glass bottle,.
Check their website maybe somebody in NZ does it.
I get mine from the UK, I am in Ireland.
Hope this is of use.
Regards
Jim
On 20 July 2017 at 10:50, donald collie donaldbcollie@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Thankyou Barry, and Ron. I should get some deoxit - the trouble would be
to get it here, because it`s in a spray "bomb", and can`t go by air [I`m in
New Zealand].USPS used to have a surface service, but I understand this is
no more. Funny thing is : I`ve tried another contact cleaner on the
contacts of the osc turret in the 606A, but it`s still doing the same thing
as the 606B, which hasn`t had "the treatment" I`m a bit puzzled as to
what`s going on, as the oscillators just drop out after a few minutes of
correct operation. ie the contact is made satisfactorally, and then for
some reason fails to make after a few minutes. I think silver contacts are
used. Cheers!.......Don
|
Re: OT: Anyone in UK (or Europe) likely to be placing an order with Lemo in the near future
If you only need one or two items try requesting a sample.
|
OT: Anyone in UK (or Europe) likely to be placing an order with Lemo in the near future
If so I'd very much like to piggy back on your order to avoid the GBP100
plus VAT MOV.
Thanks
David
|
OT: Manuals for Datron (Wavetek) 4808 Option 70 Wideband Source
Hi everyone,
I have the Schematics and Parts list for this on loan at present, but I have
had no luck finding any other documentation for it.
The edition of the user handbook for the 4808 that I have is too early to
know about this option.
I'm looking for a more up to date version of the 4808 User Manual, and the
User and Service documentation for Option 70
Hoping that someone can help with either real "dead tree" manuals or with
scans.
Thanks
Dave
|
Re: H'P606A, 606B Question
De oxit is available in non spray form, Comes in a glass bottle,. Check their website maybe somebody in NZ does it. I get mine from the UK, I am in Ireland. Hope this is of use. Regards Jim
?
Thankyou Barry, and Ron. I should get some deoxit - ?the trouble would be to get it here, because it`s in a spray "bomb", and can`t go by air [I`m in New Zealand].USPS used to have a surface service, but I understand this is no more. Funny thing is : I`ve tried another contact cleaner on the contacts of the osc turret in the 606A, but it`s still doing the same thing as the 606B, which hasn`t had "the treatment" I`m a bit puzzled as to what`s going on, as the oscillators just drop out after a few minutes of correct operation. ie the contact is made satisfactorally, and then for some reason fails to make after a few minutes. I think silver contacts are used. Cheers!.......Don
|
Re: H'P606A, 606B Question
Thankyou Barry, and Ron. I should get some deoxit - ?the trouble would be to get it here, because it`s in a spray "bomb", and can`t go by air [I`m in New Zealand].USPS used to have a surface service, but I understand this is no more. Funny thing is : I`ve tried another contact cleaner on the contacts of the osc turret in the 606A, but it`s still doing the same thing as the 606B, which hasn`t had "the treatment" I`m a bit puzzled as to what`s going on, as the oscillators just drop out after a few minutes of correct operation. ie the contact is made satisfactorally, and then for some reason fails to make after a few minutes. I think silver contacts are used. Cheers!.......Don
|
so does that mean I should connect all three pods to AD0-AD4, or just one of them?
Or should that be:
pod1 clock -> IA_H_D_L
pod2 clock -> IWR_R
pod3 clock -> IRD_L
pod3 data lines to AD0 to AD4
Thanks
Dave
toggle quoted message
Show quoted text
-----Original Message-----
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: 20 July 2017 04:33
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] 16700A setup
You might want to look at using Master/Slave clocks and Demultiplex Mode in the User's Reference manual for whatever analyzer module you are using.
You could specify the edge of IA_H_D_L as the Slave clock to latch in the address bits. Then use a combination of either IWR_R Write OR IRD_L Read edges as the Master clock to latch in the data bits from the shared ADx lines.
A logic analyzer state isn't saved until the Master clock occurs, along with the data that was latched on the last Slave clock occurrence.
------------------------------------
Posted by: Glen Slick <glen.slick@...>
------------------------------------
------------------------------------
Yahoo Groups Links
|
Re: On buying gear. A happy story.
Oops, pressed the wrong key. Picture. The intensified marker shows 33.423 MHz at the bottom just before the sweep makes its big rise. (The detector in the circuit has a negative output.) See Figure 3-2 on page 3-3 when you get the manual. All five markers work correctly. Looks like it needs only feet and cleaning to be ready for you. I need to sell the 8601A too but it may have an output problem. Don't know if I can fix it. Jeremy On Wed, Jul 19, 2017 at 10:36 PM Jeremy Nichols <jn6wfo@...> wrote: OK, it works. Here is a picture of my 8601A and the 8600A looking at a 32
MHz Lo-pass filter on my 175A scope.
On Wed, Jul 19, 2017 at 4:57 PM Roy Morgan k1lky68@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Jeremy,
Thanks, the meeting was about A Course In Miracles... my senior citizen
efforts at spirituality ?
Thanks for pictures - I would like to have found a manual before leaving
the library and internet access tonight but could not... maybe tomorrow mid
day I will find one online to read about the thing.
thanks,
Roy
On Wed, Jul 19, 2017 at 3:57 PM, Jeremy Nichols jn6wfo@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Hope the meeting goes well. Being retired here, I got roped into several
volunteer organizations and spend more time in meetings than I did when I
was working!
I'll send pictures of the 8600A.
Jeremy
On Wed, Jul 19, 2017 at 12:48 PM, Roy Morgan k1lky68@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Jeremy,
Ok sounds good. Thanks.
Address is
Roy Morgan
PO Box 101
Bernardston
MA. 01337
Physical address is 18 Center Street in case shippper can't send box
to Post office.
Glad to see there is a manual... I have lost track of the suggested web
sites that were mentioned on the HP list.
Thanks - more tomorrow or tonight... got to get food before a meeting.
Thanks much.. that thing will make my radio alignments MUCH easier.
On Wed, Jul 19, 2017 at 2:31 PM, Jeremy Nichols jn6wfo@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Roy,
My 8600A is serial number 2048A01572. It is complete and undamaged. I
need to clean it up, put feet on it, etc., and make sure it still works¡ªhas
been on the shelf for years! Also included is the factory operation/service
manual, an Ed Matsuda copy with a plastic spiral binding.
How about $125 and I'll pack and ship it for free?
Jeremy
N6WFO
On Wed, Jul 19, 2017 at 10:07 AM, Roy Morgan k1lky68@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Jeremy,
Hi, and thanks for the email. As I said, there was an 8600 for sale
recently at a very low price (fifty dollars!!) and I missed seeing it. One
other is offered at some $500. Ugh.
Anyway, if you have one, do let me know what you might want for it.
I do appreciate the possibility.
PS: If you see some garbage at the bottom of this message, I have
*tried* to delete it - I just upgraded my operating system (Mac Book) and
the editing is acting strangely.
On Wed, Jul 19, 2017 at 12:57 PM, Jeremy Nichols jn6wfo@...
[hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
Roy, I have a surplus 8600A. Please contact me off line.
------------------------------
--
Regards,
Roy
Roy Morgan
k1lky since 1958
--
Sent from my iPad 4.
--
Regards,
Roy
Roy Morgan
k1lky since 1958
--
Regards,
Roy
Roy Morgan
k1lky since 1958
--
Regards,
Roy
Roy Morgan
k1lky since 1958
--
Sent from my iPad 4.
-- Sent from my iPad 4.
|
Re: On buying gear. A happy story.
OK, it works. Here is a picture of my 8601A and the 8600A looking at a 32 MHz Lo-pass filter on my 175A scope.?
?
Jeremy,
Thanks, the meeting was about A Course In Miracles... my senior citizen efforts at spirituality ? Thanks for pictures - I would like to have found a manual before leaving the library and internet access tonight but could not... maybe tomorrow mid day I will find one online to read about the thing. thanks, Roy
|
On Wed, Jul 19, 2017 at 6:47 PM, 'David C. Partridge' david.partridge@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:
I have a set of lines as follows:
IWR_R Write Strobe (rising edge) pulsed low to write data
IA_H_D_L Address or Data on AD0-AD4
IRD_L Read Strobe (active low) pulsed low to read data
AD0
AD1
AD2 Bi-di Address/Data Lines
AD3 controlled by strobes and
AD4 IA_H_D_L
The address should be latched when IA_H_D_L goes low
I want to display the active address in hex, whether read or write, and the
value of the data
How do I set this up in an 16700A? to display the way I want it clearly it
is relatively simple to just display the "raw" signal 0/1s
I have read the training guide but seem none the wiser for doing so :(.
Thanks
Dave
You might want to look at using Master/Slave clocks and Demultiplex Mode in the User's Reference manual for whatever analyzer module you are using. You could specify the edge of IA_H_D_L as the Slave clock to latch in the address bits. Then use a combination of either IWR_R Write OR IRD_L Read edges as the Master clock to latch in the data bits from the shared ADx lines. A logic analyzer state isn't saved until the Master clock occurs, along with the data that was latched on the last Slave clock occurrence.
|
Re: Need copy/scan/borrow one page from HP 8673C/D service manual 08
|
On Thu, 20 Jul 2017 02:47:14 +0100, you wrote: I have a set of lines as follows:
IWR_R Write Strobe (rising edge) pulsed low to write data
IA_H_D_L Address or Data on AD0-AD4
IRD_L Read Strobe (active low) pulsed low to read data
AD0
AD1
AD2 Bi-di Address/Data Lines
AD3 controlled by strobes and
AD4 IA_H_D_L
The address should be latched when IA_H_D_L goes low
I want to display the active address in hex, whether read or write, and the
value of the data
How do I set this up in an 16700A? to display the way I want it clearly it
is relatively simple to just display the "raw" signal 0/1s
I have read the training guide but seem none the wiser for doing so :(. Just offhand: state mode. connect clocks to write strobe and read strobe (two pods). configure clocks to capture this on rising edge of read clock OR with write clock. If you want to see when the address sets up, I'd use either timing mode or yet a third clock for the address strobe and capture data then. timing mode works like a D flipflop, specify a signal on the clock pin and then the edge, qualify as needed. data is stored then. Same data can be viewed in timing mode, but the clock is not an edge change (any) or a timebase, it's the clock pin on the pod as you have defined it. Harvey
Thanks
Dave
|
Re: HP3582A Display unreadable
Have you tried the test switch on A9? You should get two rows of capital A's, a square wave, and two more rows of A's at the bottom.? This "isolates the Processor Ram and the Processor I/O Bus from the Display Section." (I'm quoting the Service Manual here).? It won't give you a smoking gun but will rule out some areas.
Don't feel bad, I was ignored the first time I asked a question about a fixer upper 3582A I bought too.? Got it working finally though. :)
Dave
|
Dave McGuire
David C. Partridge
Jeremy Nichols