Hi Jim, ? Uh Jim¡ I think you meant to say ¡°Cadillac¡± for the HP 8566A. It is a great Analyzer. Much earlier in my career, I would **beg** to use one for what I was working on. Very intuitive interface, set the standard for all others to follow. I still have my HP8566B. Still use it. I like it much better than any other Analyzer. ? I installed a Simmcon Labs LCD Display in my 8566. It modernizes the display of the Analyzer. ? I have a R&S FSIQ, I don¡¯t like it as much and only keep it for I/Q Demodulation and the Digital/Analog Vector Analyzer function. ? ? I should have mentioned the X and Y Capacitors need to be Safety Rated ie. X1/X2 or Y1/Y2 rated depending on Voltage requirements. Experience is required to understand how to implement the EMI fixes for Safety and Regulatory Compliance. ? ? As far as calibrating the cable for your EMI Loop Probing setup (also referred to as an EMI Sniffer), The probe results are all relative and unless you have precision calibrated Near-Field Probes like those from HP, the results are relative. You are really looking for a visual ¡°difference¡± to track down EMI noise sources. So, no real need to determine cable insertion loss unless you have a bad cable or cable adapter. ? ? As far as EMI loop Probes, the industry standard is 7405 made by Emco now owned by ETS Lindgren. They have a kit of five various probes which include: - 6cm E-Field Stub
- 6cm H-Field Loop Probe
- 3cm H-Field Loop Probe
- 1cm H-Field Loop Probe
- 3.6cm E-Field Ball Probe
- 20cm Extension Handle
- Some kits have a 10 - 20dB Preamp too.
- Carrying Case
? The Ball Probe is interesting. It will see things that the other Probes haven¡¯t. ?I have actually used the Ball Antenna as a transmitting antenna inside a shielded enclosure to get a rough idea of shielding effectiveness. ? That being said, there are a lot of EMI Loop Probe sets out there, including the ebay ones that work nearly identical and are fully usable. Even the inexpensive ones. I also have a set made by RF Explorer that I bought off of ebay. It is a higher quality set. ? You start your EMI Source search with the larger 6cm Loop Probe, find the general area of the emissions, disconnect that probe, connect the 3cm Loop Probe, narrow down the search to a smaller localized area, then move to the 1cm Loop Probe to further localize where the problem is. ? - For example, if I was troubleshooting a noisy shielded cable assembly connected to a system under test¡ I might use the 6cm Loop Probe to find ¡°which cable¡± in a cable bundle is noisy ¨C not always easy because one bad cable easily contaminates the rest of the cables until the bad one is split out. I would use the 3cm Probe to localize it to a specific cable connector. I would then use the 1 cm to find where a poor Cable Shield to Connector backshell connection is. Same thing can be done to locate a noisy IC on a Circuit Board. I rarely use the 6cm Loop Probe by the way, I almost always started with the 3cm Loop Probe.
? The Stub Antenna works well for identifying narrow slots in chassis and other items. ? Thanks for your response, I never know whether some contributions help others. Since this was a real topic that could be expounded on, I thought I would share. ? Ross ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Jim Ford Sent: Friday, September 20, 2024 8:45 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Introduction ? No apology needed, Ross!? That's a keeper!? In fact, I will print it out.? A good excuse to buy a 3 cm loop and an extra long flexible coaxial cable.? I will have to measure the loss over frequency of the cable- unfortunately my VNA only goes 300 kHz to 8 GHz.? Spec an is an old 8566A (100 Hz to 22 GHz) boat anchor and will have to remain in the rack.? Nice weekend project!? Thanks, Ross!? ? Jim Ford, Laguna Hills, California, USA? ? On Fri, Sep 20, 2024 at 7:11 PM, si_emi_01 via groups.io Hi,
I don't use LEDs for overall general or bench lighting, I have overhead Fluorescents for that. I do have a magnifier that has 144 LEDs on it that are variable in intensity. I purchased one with the Electronics at the bottom of the Boom, not near the Magnifier or Lights to keep it away from my prototyping area.
DISCLAIMER *
THE FOLLOWING IS OFFERED TO INFORM AND PROVIDE SOME STARTING SUGGESTIONS OF HOW TO LOOK AND WHERE TO LOOK FOR THE PROBLEMS ASSOCIATED WITH NOISY LED LIGHTING STRIPS (OR OTHER NOISY PRODUCTS). AGAIN, THIS IS JUST A STARTING POINT.
IT IS EXPECTED THAT KNOW HOW TO WORK WITH AC LINE POWERED ELECTRONICS AND VOLTAGES THAT EXCEED 30 VOLTS. IF NOT, DO NOT ATTEMPT TO MODIFY ANYTHING. YOU CAN STILL EMI CHARACTERIZE THE LED LIGHTING PRODUCT, THOUGH.
So, with the inexpensive LED strips there are two main issues with them Conducted EMI and Radiated EMI. You need to find out which one (or both) are the problem. It is recommended that you have an 3cm EMI Magnetic Loop Probe (purchased or home-made),? Interconnect Cable and a Spectrum Analyzer set to display frequencies from 100kHz through 1000MHz as appropriate. I am only giving information of Conducted to Radiated EMI Conversion. To provide an exact characterization, you need a Dual AC, Line Impedance Stabilization Network (LISN), and measurement in an EMI Chamber with real antennas and Receiver/Spectrum Analyzer. What is presented here is usually sufficient to EMI characterize many products.
EMI Characterization
----------------------------
You can start by using the EMI Loop Probe to probe the local environment watching the Spectrum Analyzer.
Separate the LED Lighting product from the installed location. You need at least a foot or three clearance from all other cables (plug it into a separate power strip and move it away from your bench).
0. Spectrum Analyzer Set up.
Set the Spectrum Analyzer up for a frequency range of 100kHz to 1 MHz, continuous sweep, Resolution Bandwidth of 30kHz, Reference Level 0 dB, No Attenuation (the emissions shouldn't be that high - if they are either back the probe away an inch or add attenuation).
1. Ambient EMI Emissions scan.
Turn the Light Strip Off and watching the Spectrum Analyzer Display,? just move the EMI loop Probe across (sweep), all of the surfaces in both Horizontal and Vertical orientations of the Loop Probe around the LED Light String and the Power Cord.
It should be dead with no emissions unless it uses a keep-alive circuit. Be aware that other instrument cables. If you see a lot of emissions, disconnect the Power Cord of the LED Strip, wait a few minutes for it fully discharge any bulk capacitance in the Power Supply. With it Powered off re-sweep to see a real Ambient environment.
Be aware that you may see other emissions on the Spectrum Analyzer even with everything powered-off. Those are Ambient Emissions and can be TV, Radio, other noisy equipment, room lighting - especially AC Light Dimmers, etc. emissions.
You just need to see where those emissions are, and know that they are there, so that you can mentally subtract them out when you see real Emissions from the Equipment Under Test (EUT).
Set the Spectrum Analyzer up for a frequency range of 1MHz to 10 MHz, same Resolution bandwidth and repeat an ambient sweep.
Set the Spectrum Analyzer up for a frequency range of 1MHz to 10 MHz, 100kHz Resolution Bandwidth and repeat an ambient sweep.
You now have an idea of what emissions ARE NOT coming from the LED Light Strip.
2. Product EMI Emissions.
Turn the Light String On and observe what happens on the Spectrum Analyzer as you sweep it again with it powered-on. Make note of emissions you see of what emissions are associated with physical areas of the LED Light Product. Using your phone to take pictures is a good idea, especially hot spots you see.?
You now see what the offending emissions are. Some may matter, some may not. Some of those are going to be seen as single peaks (Narrowband Emissions), that rise above the base line, some will be quite high. Some emissions will appear as groups of peaks or as large areas of the screen rise above the noise floor (Broadband Emissions - depending on the Resolution Bandwidth set on the Spectrum Analyzer). All of these emissions matter, but it is likely the Broadband Emissions are the source of the offending noise. Be aware that some emissions may occupy the same frequency space that the Ambient Emission Scan showed.
Set the Spectrum Analyzer up for a frequency range of 1MHz to 10 MHz, same Resolution bandwidth and repeat step 2.
Set the Spectrum Analyzer up for a frequency range of 10MHz to 100 MHz, 100kHz Resolution Bandwidth and repeat step 2.
Set the Spectrum Analyzer up for a frequency range of 100MHz to 1000 MHz, 1MHz Resolution Bandwidth and repeat step 2.
Same comments for Narrowband and Broadband Emission results seen on all of the Spectrum Analyzer display.
Results Evaluation.
-------------------------
You should have an idea what emissions are where now. The following is offered as suggested areas to look at.
If they are mostly below 50MHz Broadband Emissions on the Power Cable, see below discussion about the Trip-Lite EMI Filter.
If they are above 1 MHz and below 200MHz on the LED Strip Power Supply Area of the product, see below discussion about Shielding and Ferrite Cores.
If they are above 100 MHz on the LED Strip Wires or PCB that holds the LEDs, see the AC and DC LED Discussion below.
For the Conducted EMI problem...
One is that they use a Switch-mode Power Supply from AC Mains (120V/240V) to DC for the LED Controller Electronics and LED Power Source. The AC to DC Power Supply can cause multiple problems.
Those problems can be mitigated through various methods.
If it is an inexpensive Led Strip, it may or may not have adequate Power Line Filtering to keep the noise within their design and packaging. If it has an FCC B or CE-Mark it should have adequate filtering to meet the requirement - but a lot of the China stuff is marked and includes no design for compliance. Depending on their type of EMI Filter design or quality of components, and how it was tested or not, makes a big difference.
If it does have a Conducted EMI issue, that noise is impressed in Common-Mode (impressed on both Line and Neutral pins), or Differential Mode (impressed on Line or Neutral with reference to Ground).
If the noise is Common Mode, it follows through all of that power Cabling, Power Strips, etc., back to the Lowest Impedance Source. That source can be another well-designed EMI Filter (like the ones in you Spectrum Analyzers, Network Analyzers, Signal Generators and Receivers). It does not have to go back to your Power Wall Plug. And, we all have a lot of power cabling, right?
The Common Mode Conducted emissions couple into the cables and radiates off of the cables (unshielded cables can be very efficient radiators - read that as antennas - and are dependent on cable length, frequency, Impedance, coupling distance between cable, how long they are coupled, etc.). The coupled emissions become Radiated EMI which also couples into cables and wires that we are breadboarding, ungrounded, isolated or poorly grounded inputs to sensitive equipment, etc.. The Radiated Emissions E-Fields couple Capacitively to equipment cabinets and to some extent other cables, but mostly H-Field couple to other cables Magnetically into other cables and structures.
Many times, my EMI Filters designed in products have been "magnets" for other crappy designed EMI Filters in other products on the AC or DC Power Bus.
What to do?
The easiest way to diagnose if this is a problem is to use a well-designed EMI Power Filter (like a Trip-Lite ISOBar 1 or 4 or an EFI Brand Power Strip), and plug the LED Strip into it and the EMI Filter into the Power Source Outlet. The Trip-lite ISOBar device includes X and Y Capacitors as well as a Common Mode Choke in addition to Surge MOVs. A Surge Power Strip without the EMI Filtering in the ISOBar or the EFI unit will not diagnose the problem. If the emissions go down, there is a problem there. If it fixes the problem, you can't do anything with it or you will violate its Product Safety Certification - if it actually had it. But, you can use an external EMI Filter like the ISOBar and not violate Product Certification. The Trip Lite ISOBar products can be used to isolate AC EMI issues quickly.
A note about System Leakage Current:
----------------------------------------------------
With all of our equipment plugged into a common power wall outlet(s) - I usually have 27 instruments, we need to consider the leakage current induced into our "System of Systems" and that it can become too high for "Touch Current".
Each instrument has (should have), an EMI Filter composed of X and Y Capacitors to control Common-Mode and Differential-Mode Conducted EMI. All of those currents do a Vector-add since not all EMI Filters have the same values of Y Capacitors.
Many Equipment have EMI power Entry Filters that are not Powered Off at all - they stay on resident whether that instrument is creating EMI or not. Those circulating currents are on all of the chassis of our equipment that is common in the racked or shelved equipment.
Some equipment, have very aggressive EMI Filtering resulting in high value Y Capacitance in their EMI Filters, and when an Y Capacitor goes bad, how would you know it? I made a special Tektronix AC Cable Breakout TM500 Fixture with an AM503B and A6322 Current probe with an SC503. I use it periodically to check each instrument Leakage Current fore my safety. That's how I found a bad EMI Filter in my HP-4192A years ago. It tripped my GFCI Breaker on the bench Power. With all of the other instruments in parallel, it was k=just bad enough to trip it and remove the hazard it saw.
In some circumstances, all of those Vector Summed Currents may interfere with low level measurements - causing poor noise floor or erroneous measurements. Seen that happen by the way.
No man is an island.
That may or may not be a part of the problem.
The other issue is that the Power Cable itself radiates because of Conducted Emissions on it. If that is the case, wrap some Tin Foil around the whole cable length and Ground it. If that helps, the best thing to do is Z-Fold the Cable. That means that you make the total cable length about 12" with folding it back on top of itself as 12" sections. This has the EMI effect of making the cable look only 12" inches long. It does this by reversing the emission currents back on top of themselves causing the majority of those currents - and radiation strength and coupling efficiency to be reduced. Zip-tie around the ends of the cables about 2" from the ends to capture the cable loops.
You might also use a Ferrite Core on the Power Cable. A good choice for broadband power noise is a Fair-rite Corporation #44 Material or Steward Corporation #28 Material Snap-on Ferrite Core. Get one that the opening is big enough so that you can wrap the Power Cord a couple of times through the hole before you close it and lock it into place. The Ferrite Core is a low Q, crude Common Mode Choke on the cable. It looks like a low impedance to the Conducted Emissions and they are dissipated as heat in the Ferrite Material - no, they don't get hot, the currents are small.
For those of us with a lot of equipment on standby and large array of equipment, we should be Z-Folding all of our cables. Do not make them a coil of cable or let them droop, certainly, do not bundle groups of coils or groups of drooping cables.
That should address Power Line AC Conducted EMI issues in my experience. Radiated EMI issues can be problematic to solve depending on the design.
Since they are likely using a Switch-Mode Power Supply, the Outputs to the LED Array are likely unfiltered. They may even be Pulse Width Modulated (PWM) to control Color and brightness. It should be obvious that the base frequency of the PWM and we are having issues with the harmonics of the PWM edges on the wires going to the LEDs. Those wires are long of course and are likely the radiating antenna.
ALL OF THE BELOW APPLIES TO A DC ONLY OUTPUT TO THE LED STRIP ONLY.
-----------------------------------------------------------------------------------------------------
Normally, you would just add X and Y Capacitors or possibly a Common-Mode Choke to the output wires if they were straight DC. If they DC (you can control the brightness of LEDs by varying the current), great.
The DC is probably being trashed by the Switch-Mode Power Supply Output Conducted Emissions not being adequately filtered. That can happen as Common Mode or Differential Mode.
If it is Common Mode. We are trying to fix a High Frequency problem here (Switching harmonics from the Power MOSFET, Rectification Catch Diode, and Transformer Leakage Inductance), so, the values can be small and unpolarized. The X Capacitor should be 10X the value of the Y Capacitors. 1uF X Mylar Capacitor and 0.1uF for the Y Ceramic Capacitors. Those should be Probably a 100uH Common Mode Choke. Make sure the Voltage Values of the components are 3 to 4X the working Voltage of the All of this is great if it doesn't cause additional Power Dissipation in the MOSFET and Catch Diode or cause additional Conducted Emissions on the Power Line Side of the Power Supply - which they may have minimal Output Capacitance to the LED String to meet Conducted Emission Certification in the first place. You also have to make sure that the Y Capacitors do not affect the Common-Mode path back to the source - a double edge sword as a Capacitor is bi-directional and allows you to send Conducted Emissions away from the LED Strip, but also accepts Power Source Noise into the LED Strip.
If it is Differential Mode, you can use an L-C Filter on the Power Supply Output to LED Strip. Here again, the Inductor could be in the 50 to 100uH range, the Capacitor value is a little tricky here, ESR and dissipation in the Capacitor package is really important though. You need a low ESR Capacitor. You have to determine the value either by calculation or empirically. Same concerns apply for the Component Safety (including the MOSFET and Catch Diode and Product Safety). It may also create a problem with the Loop Bandwidth of the Switching Regulator.
Once again, you might also use a Ferrite Core on each wire or both wires from the Output of the Power Supply to the LED Strip. Use the same Cores except small ones that will go onto the wires - they don't have to be snap-on type, the solid ones are actually better. The longer, the better, the thicker the better (higher insertion attenuation).
ALL OF THE ABOVE APPLIES TO A DC ONLY OUTPUT TO THE LED STRIP ONLY.
FOR PWM OUTPUT DESIGNS THE FOLLOWING APPLIES.
--------------------------------------------------------------------------
For PWM Based LED Strip design, the only real thing you can do is shield it. You can't fix the output because it is AC Pulsed in nature and the chances of you causing compliance issues, damaging an output MOSFET or BJT driving the LED String is high. You will likely need to find a good way to shield the product, the internal wiring, or the PCB.
Any Output Filtering removes harmonics, for sure, but will likely increase Power Dissipation in the MOSFET Driving the LED Strip resulting in bad things up to and including ***FIRE***. The MOSFET has to stay in conduction much longer as it charges and discharges any Capacitance. It may also create a problem with the Loop Bandwidth of the Switching Regulator.
IT IS NOT RECOMMENDED THAT YOU FIX THE PWM DESIGNS FOR RELIABILITY, REGULATORY COMLIPANCE AND *** SAFETY ***. JUST SHIELD IT OR GIVE UP IN MY OPINION, DESIGN A CURRENT MODE DESIGN IF YOU WANT TO VARY THE INTENSITY.
Sorry for the long email.
Ross
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of John Griessen via groups.io
Sent: Thursday, September 19, 2024 6:34 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Introduction
On 9/19/24 15:53, Radu Bogdan Dicher wrote:
> when you align FM tuners (uV of signal) or do metrology applications, this noise can be a determining factor.
Yeah,? I've been thinking of a zero crossing and filtered and shielded and low frequency switcher supply to make and sell for LEDs in labs.
The usual products are designed for "don't care" how much EMI, and low cost.
|
Re: HP 8554B, no RF after first successful run...
Its a simpson 260, open to hearing any tips before i go in!
Some analog VOMs put out enough current to fry a mixer diode.
I did re-check, and I've since gotten more?problems in?this?area...? ? ? :-D? -10v supply is no longer happy..??
Lot of people saying it might be the mixer diodes, so I may check those w/ my old analog meter today after I look?
over MORE POWER SUPPLIES....? ??
Hi Bill,
?
When I first read your post I thought you did some very low frequency stuff.?
Actually you're referring to MHz (Megahertz), not mHz (Millihertz).
?
Since you left the unit running for a while until the fault condition appeared: did you re-check once it was cold again? Like after 24 hours?
?
cheers
Martin
|
Re: HP 8554B, no RF after first successful run...
Some analog VOMs put out enough current to fry a mixer diode.
toggle quoted message
Show quoted text
I did re-check, and I've since gotten more?problems in?this?area...? ? ? :-D? -10v supply is no longer happy..??
Lot of people saying it might be the mixer diodes, so I may check those w/ my old analog meter today after I look?
over MORE POWER SUPPLIES....? ??
Hi Bill,
?
When I first read your post I thought you did some very low frequency stuff.?
Actually you're referring to MHz (Megahertz), not mHz (Millihertz).
?
Since you left the unit running for a while until the fault condition appeared: did you re-check once it was cold again? Like after 24 hours?
?
cheers
Martin
|
Re: HP 8554B, no RF after first successful run...
I did re-check, and I've since gotten more?problems in?this?area...? ? ? :-D? -10v supply is no longer happy..?? Lot of people saying it might be the mixer diodes, so I may check those w/ my old analog meter today after I look? over MORE POWER SUPPLIES....? ??
Hi Bill,
?
When I first read your post I thought you did some very low frequency stuff.?
Actually you're referring to MHz (Megahertz), not mHz (Millihertz).
?
Since you left the unit running for a while until the fault condition appeared: did you re-check once it was cold again? Like after 24 hours?
?
cheers
Martin
|
....but the years are long.
I almost missed that. Another "like the hot kiss at the end of a wet fist" moment.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz, STK, ca. 1994)
==============================
toggle quoted message
Show quoted text
On Sep 21, 2024, at 09:58, Harvey White via groups.io <madyn@...> wrote:
?Art is long....
(apologies if I misremember that).
Harvey
On 9/21/2024 5:14 AM, David C. Partridge wrote:
Life is short.
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Harvey White
Sent: 21 September 2024 00:44
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Introduction
Lazarus Pascal, and no idea why they named it like that, their product picture is a cheetah.
Maybe one of the designers is a Howard?
Harvey
On 9/20/2024 6:50 PM, Dave Daniel wrote:
A longer reply is due.
BUT ... "Lazarus", as in RAH's "Lazarus Long"?
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz,
STK, ca. 1994) ==============================
On Sep 20, 2024, at 18:36, Harvey White via groups.io <madyn@...> wrote:
?Pascal became windows pascal, which went nowhere, and was paralled by free pascal, which morphed in a kind of parallel development into Lazarus Pascal. That has pretty much all that visual C has, or perhaps had. The Borland (pascal) version became Delphi and became an egregiously for Profit version. Lazarus is free and object oriented too.
Delphi is object oriented. So is Lazarus.
There was a language called PLM-86 (intel) that I used for a good while, but not Object Oriented Programming (OOP).
I did C, then when I went from the 6502 (assembly only or tiny forth), then C (AVR), then finally C++ when I got into the ARM (STMicro) world. I have a graphics driver setup that is written in C++, and the hardware driver structure is in C (ST Micro) with a C++ overlay. FreeRTOS gets thrown in there, too.
Depends on what you're doing, but for some things, C++ and OOP make a lot of sense.
Harvey
On 9/20/2024 6:09 PM, Dave Daniel wrote:
Yeah, Modula-2 never caught on. Neither did Pascal, actually. I did all my Applied Math programming in FORTRAN (calculating the zeroes of Bessel functions as a homework assignment at ~0600 on a weekday morning and getting a 'phone call from the data center sysadmin: "Dave, what are you running? You are using 98% of the CPU"). Later, of course, at work, everything was done using C or assembler. C++ came later; my only experience with OOP has been with SystemVerilog.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 15:08, Harvey White via groups.io <madyn@...> wrote: ?I never found any Modula-2 compilers. I looked at what was out there (circa 1980 or so) and I got what would work on a PC for free.
Strictly low budget (and still, in a way, am).
Harvey
On 9/20/2024 2:45 PM, Dave Daniel wrote:
Pascal was originally intended to be a "teaching" language only and was never intended to be used commercially. Modula-2 was supposed to fix that.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 13:44, Harvey White via groups.io <madyn@...> wrote: ?Nope, Borland Pascal, then Delphi.
It is possible to break the linker in Borland Pascal.
Harvey
On 9/20/2024 12:36 PM, Dave Daniel wrote:
Pascal? Did you ever write code in Niklaus Wirth's Modula-2?
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 09:52, Harvey White via groups.io <madyn@...> wrote: ?You're welcome. I can take a design from concept to hardware to pc board to build and then do the same for software. Limitations, of course.
I always encouraged my students to learn both hardware and software, even if they were not going to use it immediately (either!).
I have a program written in C++ (on the PC) that parses an EAGLE board file, then produces an OpenSCAD file (will need custom OpenSCAD parts) to model the board. Makes it useful for designing cases and assemblies as well as getting an idea of what fits where.
So current languages? embedded C, C++ for microprocessors, C++ for the PC, VHDL for FPGAs, OpenSCAD for 3D designs.
I have mostly dropped Delphi, which can be somewhat annoying to code in. Not a bad language (Pascal), but gives me no transportability to the microprocessor realm.
I do mostly digital and power supply design (in support), with a reasonably heavy concentration in microprocessors.
Harvey
On 9/20/2024 9:27 AM, Frank Mashockie wrote:
Thanks Harvey!
I really appreciate the feedback. The software is definitely my weakest point. I think it might be a good idea to start introducing myself to some of it. I've gotten familiar with programming development software to flash MCUs, but that is about it.
I love repair of PCBs. The problem solving and troubleshooting. Learning more about different types of circuits. With that, I think I'd like to get into PCB design. Definitely hardware related. But I guess I won't know for sure until I get into that degree - there's still so much I need/want to learn. I am also interested by power systems and the grid. I probably would have been a lineman if I wasn't afraid heights!
Sorry I don't mean to derail the thread, but I greatly appreciate the feedback!
-Frank
|
Oh the damage I have done with vi! I am an emacs guy, and have the emacs mode-less editor model permanently seared into my brain... Invariably, while using vi, I will forget that I am in command mode, and will touch type a bunch of text, at a furious rate, into being some random command. I won't notice what I have done, until one of my random text/commands honks off vi, and causes it to issue stream of beeps in complaint. When I look up at the screen, I will see that I have blown away a thousand lines of my code, started a few new processes, opened three or four spurious command line windows, and condemned myself to a half day's trying to fix the damage done... Early in my career, I found jove, which stands for (Jonathan's Own Version of Emacs). Jove was written by Jonathan Payne when he was a high school student, and I have ported it to every machine I have ever worked with, unix, msdos, or windows. Now a days, jove is in the debian linux repositories, so it too is available everywhere in linux. Jove is a tiny fraction of the size of vi, or emacs, and can do anything vi can do. I quickly install it on every machine I use and ditch vi. Once, as the sole user, I took down a customer's home grown 68000 based machine, with its home grown port of unix, while I was using it as a development system... I am told, simply by using jove. It took the guy that did the original unix porting a weekend to reassemble the system disk, and bring the machine back up. He forbade me from using jove on his machine, while being totally deaf to my protestations that if a user process can damage a unix system, there is a far bigger problem that needs fixing, than what the user was running... So, I was stuck using vi. About mid week after he banished me to vi, I crashed his machine down again, whilst using vi. This time, it took him a full week to put his machine back together... with some rumblings about my now being responsible for backing up his machine. He also decided that the problem was really me, so he banished me to using a Sun Workstation... -Chuck Harris On Fri, 20 Sep 2024 11:31:17 -0400 "Dave Daniel" <kc0wjn@...> wrote: Eeek! I used EMACS until I realized that vi was always available on
any UNIX system (vi, vim, gvim, etc.) and I kept getting "assigned"
sysadmin duties on every friggin UNIX-like system STK Printer Ops
acquired, and needed an editor upon which I could always rely. I
still have that yellow comb-bound EMACS book somewhere. Using EMACS
gave me my first exposure to the Gnu Public License. Dang. For an
EE/Physics major, entering into the UNIX/HPUX/VMS/SunOS/Solaris world
where people actually *argued* about using EMACS or vi or ed was kind
of like entering Oz. I scurried back to my electrons and holes as
quickly as I was able. LOL.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz,
STK, ca. 1994) ==============================
On Sep 19, 2024, at 19:57, Dave McGuire via groups.io
<mcguire@...> wrote:
?
Emacs!
On 9/19/24 19:53, Harvey White wrote:
Unless you like VHDL...... <grin>
Harvey
On 9/19/2024 5:29 PM, Dave Daniel wrote:
Add in SystemVerilog if one is contemplating FPGA/ASIC work.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 19, 2024, at 16:03, Roy Thistle via groups.io
<roy.thistle@...> wrote:
?
On Thu, Sep 19, 2024 at 09:11 AM, Frank Mashockie wrote:
I've been considering going into an online master's program
for EE.
If your boss is not paying for it... It's expensive.
2 to 3 years to complete, on average.
Say 50,000USD total cost, on average... and up... for many good
US schools. Georgia Tech is... about the lowest cost...
10,000USD total cost. Everyone is different... but IMO... the
average person... depending on which specialty they want...
needs to have a strong background in calculus... as in vector,
complex, and differential equations... linear algebra...
numerical methods... statistics. Computer science skills are
required too. Programming in Python or C Simulations in software
packages like Pspice HDL like Verilog, or VHDL Not to mention a
strong background in circuit analysis
devices
probably other stuff I forgot too.
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Art is long....
(apologies if I misremember that).
Harvey
toggle quoted message
Show quoted text
On 9/21/2024 5:14 AM, David C. Partridge wrote: Life is short.
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Harvey White
Sent: 21 September 2024 00:44
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Introduction
Lazarus Pascal, and no idea why they named it like that, their product picture is a cheetah.
Maybe one of the designers is a Howard?
Harvey
On 9/20/2024 6:50 PM, Dave Daniel wrote:
A longer reply is due.
BUT ... "Lazarus", as in RAH's "Lazarus Long"?
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz,
STK, ca. 1994) ==============================
On Sep 20, 2024, at 18:36, Harvey White via groups.io <madyn@...> wrote:
?Pascal became windows pascal, which went nowhere, and was paralled by free pascal, which morphed in a kind of parallel development into Lazarus Pascal. That has pretty much all that visual C has, or perhaps had. The Borland (pascal) version became Delphi and became an egregiously for Profit version. Lazarus is free and object oriented too.
Delphi is object oriented. So is Lazarus.
There was a language called PLM-86 (intel) that I used for a good while, but not Object Oriented Programming (OOP).
I did C, then when I went from the 6502 (assembly only or tiny forth), then C (AVR), then finally C++ when I got into the ARM (STMicro) world. I have a graphics driver setup that is written in C++, and the hardware driver structure is in C (ST Micro) with a C++ overlay. FreeRTOS gets thrown in there, too.
Depends on what you're doing, but for some things, C++ and OOP make a lot of sense.
Harvey
On 9/20/2024 6:09 PM, Dave Daniel wrote:
Yeah, Modula-2 never caught on. Neither did Pascal, actually. I did all my Applied Math programming in FORTRAN (calculating the zeroes of Bessel functions as a homework assignment at ~0600 on a weekday morning and getting a 'phone call from the data center sysadmin: "Dave, what are you running? You are using 98% of the CPU"). Later, of course, at work, everything was done using C or assembler. C++ came later; my only experience with OOP has been with SystemVerilog.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 15:08, Harvey White via groups.io <madyn@...> wrote: ?I never found any Modula-2 compilers. I looked at what was out there (circa 1980 or so) and I got what would work on a PC for free.
Strictly low budget (and still, in a way, am).
Harvey
On 9/20/2024 2:45 PM, Dave Daniel wrote:
Pascal was originally intended to be a "teaching" language only and was never intended to be used commercially. Modula-2 was supposed to fix that.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 13:44, Harvey White via groups.io <madyn@...> wrote: ?Nope, Borland Pascal, then Delphi.
It is possible to break the linker in Borland Pascal.
Harvey
On 9/20/2024 12:36 PM, Dave Daniel wrote:
Pascal? Did you ever write code in Niklaus Wirth's Modula-2?
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 09:52, Harvey White via groups.io <madyn@...> wrote: ?You're welcome. I can take a design from concept to hardware to pc board to build and then do the same for software. Limitations, of course.
I always encouraged my students to learn both hardware and software, even if they were not going to use it immediately (either!).
I have a program written in C++ (on the PC) that parses an EAGLE board file, then produces an OpenSCAD file (will need custom OpenSCAD parts) to model the board. Makes it useful for designing cases and assemblies as well as getting an idea of what fits where.
So current languages? embedded C, C++ for microprocessors, C++ for the PC, VHDL for FPGAs, OpenSCAD for 3D designs.
I have mostly dropped Delphi, which can be somewhat annoying to code in. Not a bad language (Pascal), but gives me no transportability to the microprocessor realm.
I do mostly digital and power supply design (in support), with a reasonably heavy concentration in microprocessors.
Harvey
On 9/20/2024 9:27 AM, Frank Mashockie wrote:
Thanks Harvey!
I really appreciate the feedback. The software is definitely my weakest point. I think it might be a good idea to start introducing myself to some of it. I've gotten familiar with programming development software to flash MCUs, but that is about it.
I love repair of PCBs. The problem solving and troubleshooting. Learning more about different types of circuits. With that, I think I'd like to get into PCB design. Definitely hardware related. But I guess I won't know for sure until I get into that degree - there's still so much I need/want to learn. I am also interested by power systems and the grid. I probably would have been a lineman if I wasn't afraid heights!
Sorry I don't mean to derail the thread, but I greatly appreciate the feedback!
-Frank
|
I'd been using it for the last fifteen years or so.
I dropped it for several reasons:
1. I think I remember running into some difficult to fix errors on
their end
2. The code became less useful as I started using C++ more and more.
3. I could not transfer the pascal code from there to an embedded
processor.
4. Making my own components never quite worked well enough. (I do
programmed arrays of stuff)
5. exactly like C++, the button class is very limited, made my own from
a panel.
So I'm doing quite similar projects in "Embarcadero" C++, having tried Microsoft VC (and not comprehending the startup menu because they have different names for everything).? Tried Eclipse C (no drag and drop for the UI).? Tried some of the commercial graphics products with an experimenter license, couldn't get them to work (inadequate documention at critical points).? Borland C++ (Embarcadero) seemed the only thing left. <sigh>.
I did get a complete application written in it with a decent enough repeatable UI (avoid templates, they refer back to the original code with links regardless of what they say).? So I'll stick with that for a while.
Harvey
toggle quoted message
Show quoted text
On 9/21/2024 5:10 AM, Dave_G0WBX via groups.io wrote: Re:-
From: Harvey White <mailto:madyn@...?subject=Re:%20Introduction>
Date: Fri, 20 Sep 2024 17:44:05 GMT
Nope, Borland Pascal, then Delphi.
It is possible to break the linker in Borland Pascal.
Harvey
Have you looked at ?
Largely cross platform, and fairly Delphi compatible too.
Even sporting a Delphi project import function, that "mostly" works, but usually needs some code fiddling in respect to any serial I/O or Networking.
Dave B (UK)
--
Created on and sent from a Unix like PC running and using open source software:
|
Re: GPIB software: Prologix and Python
Given the code example friendly issued by Chuck I could not
resist and spend a couple of hours to test it with my HP437B power
meter. The result is not A-level programming but just a script
that works. I have not used my Prologix GPIB adapter for many
years. The advantage over the HP82357 is that you have more
control over the GPIB lines, if you want. The HP adapter seems (much) faster to me.
Use it as you wish.
Cheers,
Harke
# try out some gpib data collection using the Prologix gpib-usb controller
# Chuck Harris
# Harke Smits
# Test for HP437B power meter @ GPIB address 3
# serial data format: bytes....----> str.encode("..")
# Sept 2024
import serial
import time
def gpib_init():
ser.write(str.encode("++mode 1\r")) # Controller mode
time.sleep(0.1)
ser.write(str.encode("++ifc\r")) # assert IFC line
time.sleep(0.1)
ser.write(str.encode("++auto 0\r")) #
time.sleep(0.1)
ser.write(str.encode("++eoi 0\r")) # disable EOI assertion
time.sleep(0.1)
def gpib_read(addr):
ser.write(str.encode("++addr " + str(addr) + "\r"))
time.sleep(0.1)
ser.write(str.encode("++read eoi\r"))
return ser.readline().strip()
def gpib_write(addr,gpibstr):
ser.write(str.encode("++addr " + str(addr) + "\r"))
time.sleep(0.1)
ser.write(str.encode(gpibstr + "\r"))
def check_srq():
srq = False
ser.write(str.encode("++srq\r"))
srq = (int(ser.readline()) == 1)
return srq
#
# test program...
#
ser = serial.Serial('COM4',rtscts=0,timeout=1) # verify COM number
gpib_address = 3 # HP437B power meter default GPIB address
ser.write(str.encode("++ver\r")) # Prologix version
print(f"Prologix controller version: {ser.readline().strip()}")
gpib_init()
gpib_write(gpib_address,"*RST\r")
time.sleep(0.5)
gpib_write(gpib_address,"IDN?\r")
print("ID = " + str(gpib_read(gpib_address)) + "\r")
gpib_write(gpib_address,"PR\r") # Preset cmd
time.sleep(0.1)
gpib_write(gpib_address,"CSZE\r") # Zero command
time.sleep(0.1)
print(f"Zeroing power meter")
while not check_srq():
print(".", end=" ", flush=True)
time.sleep(0.2)
gpib_write(gpib_address,"CSCL100%\r") # Calibrate command, adjust cal fac if necessary
time.sleep(0.1)
print(f"\r\nCalibrating power meter")
while not check_srq():
print(".", end=" ", flush=True)
time.sleep(0.2)
time.sleep(5) # PWM needs time to autorange
gpib_write(gpib_address,"ERR?\r") # check the error code: zero is all ok
print(f"\r\nError code line 71: {int(gpib_read(gpib_address))}")
value = str(gpib_read(gpib_address).strip())
print(f"RF power: {value} dBm.\r")
print(f"end")
|
HP 8566B Not Showing Any Signal
Hello All!
?
This is my first post here, and I'm super glad to have found this group. I'm working on an HP 8566B that I purchased locally in Dallas.
?
When I got the unit, the only issue I thought I had was an occasional YTO unlock light. Now, as I¡¯ve been playing with it and trying to test signals into the front of the unit, I find that the CAL signal does not show up on the RF input.
Tonight, I really got into it thinking that the attenuator must be at fault based on some YouTube videos I¡¯ve watched showing similar symptoms. Attached is a video showing some of the things that I¡¯m seeing. If you can share any light on any of this, I¡¯d be super grateful.
?
?
After I film this video, I went ahead and torn into it and removed the attenuator block. When I removed the attenuator block, I noticed that the press on connector that connects the attenuator to the motherboard had a pin that was flattened and never made contact in the female header. I assumed I had found my problem tonight so I straightened the pin out and carefully reassembled. It fired it up and I have the exact same issues as before. No matter what amount of signal I run into the input analyzer I¡¯m not able to see it.
The frustrating thing is that yesterday when I was playing with it I was able to see the signal when I ran the reference level down to -27 DB. Luckily I have a unit here so tomorrow night time allowing, I¡¯ll try to pull either the entire YIG sub assembly out and swap that in or merely just swap out the continuator.
Thanks again!
Brad Jackson
|
On 9/21/24 02:37, Tony Goodhew wrote: I'm on vacation near Shell Knob in Missouri and I'm trying to catch up with this. mammoth thread...
Dave,
I feel the need to come clean with everyone that I was the PM who killed EMACS emulation in Visual Studio back in the early 2010s.
In my defense, that usage data showed almost zero people used it and the maintenance cost exceeded that.
To all the EMACS adherents out there I apologize, No impact here; I'd not touch Visual anything with a ten-foot pole. I run *emacs*. Near-zero usage for such an emulation is not surprising at all. People who want an emacs emulation probably want it because they've run emacs in the past, and such people are probably still running emacs. Further, most Windows people I've met tend not to dig around and explore things, they just do what they're told. If you guys didn't tell them "hey, try emacs mode!" they probably didn't. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
On 9/21/24 04:56, Dave Daniel wrote: LOL. You never worked at Documation. We had a lot of fun doing weird ...uh... stuff there. It was kind of like being professional adolescents. When Storage Technology bought Documation, we all had to "grow up". But that was in the late 70s and early 80s. Haa, no I never worked there. But I was in the startup company world for a long time; it sounds like the attitudes are similar. :) But even there, we never wire-wrapped in humor. ;) We do have a few Documation card readers at the museum. None working yet; we must fabricate new rollers for them. It was during my stay at Doc that I wirewrapped the only card that I ever built that worked flawlessly without needing rework - a 128 kB memory card, using Intel 2 kB memory ICs, IIRC. Nice! -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
Re: HP8563E strange behavior
I should add that there are no visible error notifications on the screen.
|
Re: HP 8554B, no RF after first successful run...
Hi Bill,
?
When I first read your post I thought you did some very low frequency stuff.?
Actually you're referring to MHz (Megahertz), not mHz (Millihertz).
?
Since you left the unit running for a while until the fault condition appeared: did you re-check once it was cold again? Like after 24 hours?
?
cheers
Martin
|
Delphi was very popular in Europe, Germany especially.
There is also (previously? mentioned in another thread) EZGPIB, that is a Pascal based scripting system, for GPIB instrument/device control.
I believe that was probably created with Delphi.
Sadly it's author has passed, but his site lives on.
It's a Windows program, but will run in a guest VM on other OS's, if they can make USB peripherals available to the guest.? I've run it with NI-GPIB and common USB/Serial devices, running in a XP VM as a guest on Linux Mint in the past.
Regards.
Dave B (UK)
--
Created on and sent from a Unix like PC running and using open source software:
|
Life is short.
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Harvey White Sent: 21 September 2024 00:44 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Introduction Lazarus Pascal, and no idea why they named it like that, their product picture is a cheetah. Maybe one of the designers is a Howard? Harvey On 9/20/2024 6:50 PM, Dave Daniel wrote: A longer reply is due.
BUT ... "Lazarus", as in RAH's "Lazarus Long"?
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz,
STK, ca. 1994) ==============================
On Sep 20, 2024, at 18:36, Harvey White via groups.io <madyn@...> wrote:
?Pascal became windows pascal, which went nowhere, and was paralled by free pascal, which morphed in a kind of parallel development into Lazarus Pascal. That has pretty much all that visual C has, or perhaps had. The Borland (pascal) version became Delphi and became an egregiously for Profit version. Lazarus is free and object oriented too.
Delphi is object oriented. So is Lazarus.
There was a language called PLM-86 (intel) that I used for a good while, but not Object Oriented Programming (OOP).
I did C, then when I went from the 6502 (assembly only or tiny forth), then C (AVR), then finally C++ when I got into the ARM (STMicro) world. I have a graphics driver setup that is written in C++, and the hardware driver structure is in C (ST Micro) with a C++ overlay. FreeRTOS gets thrown in there, too.
Depends on what you're doing, but for some things, C++ and OOP make a lot of sense.
Harvey
On 9/20/2024 6:09 PM, Dave Daniel wrote:
Yeah, Modula-2 never caught on. Neither did Pascal, actually. I did all my Applied Math programming in FORTRAN (calculating the zeroes of Bessel functions as a homework assignment at ~0600 on a weekday morning and getting a 'phone call from the data center sysadmin: "Dave, what are you running? You are using 98% of the CPU"). Later, of course, at work, everything was done using C or assembler. C++ came later; my only experience with OOP has been with SystemVerilog.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 15:08, Harvey White via groups.io <madyn@...> wrote: ?I never found any Modula-2 compilers. I looked at what was out there (circa 1980 or so) and I got what would work on a PC for free.
Strictly low budget (and still, in a way, am).
Harvey
On 9/20/2024 2:45 PM, Dave Daniel wrote:
Pascal was originally intended to be a "teaching" language only and was never intended to be used commercially. Modula-2 was supposed to fix that.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 13:44, Harvey White via groups.io <madyn@...> wrote: ?Nope, Borland Pascal, then Delphi.
It is possible to break the linker in Borland Pascal.
Harvey
On 9/20/2024 12:36 PM, Dave Daniel wrote:
Pascal? Did you ever write code in Niklaus Wirth's Modula-2?
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick
Renz, STK, ca. 1994) ==============================
On Sep 20, 2024, at 09:52, Harvey White via groups.io <madyn@...> wrote: ?You're welcome. I can take a design from concept to hardware to pc board to build and then do the same for software. Limitations, of course.
I always encouraged my students to learn both hardware and software, even if they were not going to use it immediately (either!).
I have a program written in C++ (on the PC) that parses an EAGLE board file, then produces an OpenSCAD file (will need custom OpenSCAD parts) to model the board. Makes it useful for designing cases and assemblies as well as getting an idea of what fits where.
So current languages? embedded C, C++ for microprocessors, C++ for the PC, VHDL for FPGAs, OpenSCAD for 3D designs.
I have mostly dropped Delphi, which can be somewhat annoying to code in. Not a bad language (Pascal), but gives me no transportability to the microprocessor realm.
I do mostly digital and power supply design (in support), with a reasonably heavy concentration in microprocessors.
Harvey
On 9/20/2024 9:27 AM, Frank Mashockie wrote:
Thanks Harvey!
I really appreciate the feedback. The software is definitely my weakest point. I think it might be a good idea to start introducing myself to some of it. I've gotten familiar with programming development software to flash MCUs, but that is about it.
I love repair of PCBs. The problem solving and troubleshooting. Learning more about different types of circuits. With that, I think I'd like to get into PCB design. Definitely hardware related. But I guess I won't know for sure until I get into that degree - there's still so much I need/want to learn. I am also interested by power systems and the grid. I probably would have been a lineman if I wasn't afraid heights!
Sorry I don't mean to derail the thread, but I greatly appreciate the feedback!
-Frank
|
Re:-
From: Harvey
White
Date: Fri, 20 Sep 2024 17:44:05 GMT
Nope, Borland Pascal, then Delphi.
It is possible to break the linker in Borland Pascal.
Harvey
Have you looked at? ? ?
Largely cross platform, and fairly Delphi compatible too.
Even sporting a Delphi project import function, that "mostly"
works, but usually needs some code fiddling in respect to any
serial I/O or Networking.
Dave B (UK)
--
Created on and sent from a Unix like PC running and using open source software:
|
Re: HP 141T Power Supply Help Needed
Does it "Bloom" with the trace intensity set to minimum?
It does look like the storage sub-system needs attention.
Dave B. (UK)
--
Created on and sent from a Unix like PC running and using open source software:
|
Hi again.
Ah..? the "Large Scale Systems Museum".? That's been mentioned
before here.
If I'd known about that a few years ago, I'd have 110% definitely
visited at least once, as I used to visit a company at Souderton PA
on an irregular basis, & did the drive from there to Dayton for
the Hamfest back in 2015, with some (also licenced) colleagues who
had other business near Pittsburgh.? Resulting in a solo drive back
a few days later in some truly horrendous weather!? 4+ hours each
way.? (A bit like driving 200 miles on the M6 in the UK these days!)
I did get to spend half a day (not enough) at the Wright Patterson
Airospace Museum, another one I'd like to re-visit.
In an earlier past employment, where I was working with the DG
systems, one of my main functions was rebuilding crashed hard
drives.? Perkin Elmer, Diablo, Wangco, and the (then) advanced CDC
multi platter 96Meg units.? (I could lift one from the rack, onto
the bench back then, not now sadly!)
Full physical strip-downs and clean, then rebuild, purge and
re-align/calibrate, before thrashing the heck out of them with the
stressful (not just for the drive!) Random Read test.? Some drives
would have to be "secured" to the bench when that test was run, and
loose articles nearby removing.
We were even recovering some crashed heads with careful cleaning, if
they were just lightly damaged by accumulated debris.? Saved a ton
of money doing that...? Quite impressive how much physical
punishment some would take, then polish up like new and work just
fine afterwards.
(Plenty of "over qualified incompetent customer" stories accumulated
as a result of that work too!)
One of the few tasks, where no one really complained about the time
taken, as we found that the more care and time spent during the
rebuild and setup, the better they performed.? Even better,
enjoyable work as well.
I doubt very much I'll make it back to the US under my own steam
now.? Pitty, as I perhaps could help with your Tek 4014 problem, as
I also worked for Tek in the UK in the past, so those CRT storage
display systems I understand too.
Just a thought, do you home any of the DG Micro Nova systems?? That
were advertised as being "IBM PC Compatible" (with the 8086
co-processor card.)
Of course, by then, hard drives were mostly non-DIY fixable, sadly.
Regards to All.
Dave B (G8KBV)? Ex GPO Telecom, Tek', Finnigan MAT Ltd, Texscan, and
then way too long at AR UK.
--
Created on and sent from a Unix like PC running and using open source software:
|
LOL. You never worked at Documation. We had a lot of fun doing weird ...uh... stuff there. It was kind of like being professional adolescents. When Storage Technology bought Documation, we all had to "grow up". But that was in the late 70s and early 80s.
It was during my stay at Doc that I wirewrapped the only card that I ever built that worked flawlessly without needing rework - a 128 kB memory card, using Intel 2 kB memory ICs, IIRC.
DaveD
KC0WJN
Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz, STK, ca. 1994)
==============================
toggle quoted message
Show quoted text
On Sep 20, 2024, at 19:29, Dave McGuire via groups.io <mcguire@...> wrote:
?On 9/20/24 17:27, Dave Daniel wrote:
I had a wirewrapped Apple motherboard. I built a Heathkit H-something monitor and used that system for a couple of years. The Apple motherboard was wirewrapped as a sort of joke or something. I ended up with it because no one else wanted it. Probably worth a good bit now.
I've never known anyone to wire-wrap anything as a joke. That's...just weird.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Brad Jackson
Dave McGuire
Martin
David C. Partridge