Before I realized I was old and could afford the good stuff, I was very focused on low cost T&M kit.

Here's my current absolute cheapest acceptable quality RF suite:

Hanmatek DOS1104
F***Elec FY6900-50
Frequency counter ???
nanoVNA H
tinySA
BSIDE ESR02 Pro
diode noise source
OXCO <10e-9
TQP3M9037-LNA
-60 db x 1 dB JFW step attenuation DC-2 GHz. or similar

The DOS1104 only has 20k of memory, so not good for serious embedded work, but it also gives very fast and accurate FFT updates though with incorrect labeling if you are aliased. But it's also 1/2 the price of the deep memory Owon version which really isn't competitive in the $400 range.

Can anyone think of anything else to add?

Have Fun!
Reg

Reg,

I would upgrade to:

NanoVNA-H2
tinySA-Ultra

If operating portable outdoors I would upgrade to SAA-2N. It has a brighter screen and push buttons which are far less cumbersome than the thumbwheel switch.

My portable pack also includes a YIRU UNI-T UT210 Series True RMS Digital Clamp Meter. Clamp meter measures DC as well as AC current.

I do lots of portable operating in the summer.

Mike N2MS

I neglected to mention I priced the list out on Aliexpress last night at about $600. I think that is fantastic as it's a sum a student can afford. And actually move easily at the end of the school year.

At the moment I'm using the DOS1104 to compare a 10 MHz square wave from a Keysight 33622A and an F***Elec FY6900.

There are many options for better instruments. I was asking if there were anything essential I'd left out.

Have Fun!
Reg

Here the DOS1104 compares the F***Elec FY6900 and a Keysight 33622A generating 10 MHz square waves. The faster risetime is the Keysight. Both 128 trace averages.

I should note that a flaw in the FY6900 has the consequence that only the range from 0.5001 to 5.0000 V produces an accurate square wave. To evaluate the noise of the DSO I used a step attenuator to reduce the signal to fit the scope display at maximum sensitivity. The two traces are about 100x difference in price. I'd like to point out that both the AWGs were set to 0.5001 V and a JFW step attenuator used to adjust the level to the 5 mV/div range. So a cable shift between the two. Nothing else changed. I find the voltage agreement between the two units quite amazing.

The DSO is surprisingly low noise, significantly less so than the 1102.

I've done a lot of experiments testing the DSO, far more than I care to write up. The idea that this is available for under $200 USD with another $100 for the AWG blows my mind.

By the time you add PSU, cables, adapter and other bits a $1000 full lab is capable of doing a superb job on most design and diagnostic work. That's significant. A motivated individual working 3 months or so at minimum wage can acquire that. Add some books and videos on youtube and a person can become a quite competent RF engineer in a few years of evening and weekend hobby work. That represents a substantial intellectual asset. That opportunity didn't exist 20 years ago.

Have Fun!
Reg

On Wed, Dec 20, 2023 at 06:21 PM, Reginald Beardsley wrote:

Can anyone think of anything else to add?

Besides being 'light' on memory (Which... IMO... seems odd... but is probably for 'reasons?') [ Don't ask me what 'reasons' means; but, apparently some people think it explains 'stuff' ...not sure.])
Anyway....
Besides being light on memory... it's pretty light on decoders too... since essentially... it doesn't have any. (And so, the self-taught engineer might be missing some parts of the digital revolution.)
Also no battery... and no place? to put one. (Feels wrong without a battery.)
Also, feels strange working with a DSO (with no battery) where the power cord (mains cable... if your British?) is almost heavier than the scope. (Be prepared to chase it around the room, if you'r AC is a large fan.)
And what about that IEC C13/14 exiting the side... instead of the back? (Maybe that's better? ... since it won't blow away when you lie it flat?)
A lot of 'feels like to me' type analysis... I admit... but, when using a tool... a lot of 'feels like' stuff comes to mind... at least for me.

Anyway... it might be ok for analog/audio work... and if? you don't have much bench space... or money (who has enough monen?... not me)... and you have no urge for quality. (often overcome by reality...really.)

IMO... it's mostly an 'analog' DSO... which is far cheaper (and does a bit more useful) stuff than you could do with a Tek 465.)
But I wouldn't trade a 465 for DOS1104.

Time will tell... but IME...and at least... those 25 cent? encoders, and pots... may not hold up... even compared to the ones on a current 465 old timer.

On Thu, Dec 21, 2023 at 01:45 PM, Reginald Beardsley wrote:

Add some books and videos on youtube and a person can become a quite competent RF engineer in a few years of evening and weekend hobby work. That represents a substantial intellectual asset.

Can't say where other's went to EE school; but..
IMO... and in my university... it might have been different.
I'd say that tech talk on YouTube is mostly edutainment (nothing wrong with that for entertainment)
And pop-engineering books (even with a bit of math) are not very good... whilst... textbooks have gotten bad as well too.
I'd reckon I've spent hundreds... even thousands of hours... watching YouTube tech channels... and maybe only a handful of times had 'the experience.'
I can explain 'the experience' but can firstly finish off YouTube as a source of 'the experience' by just saying that YouTube doesn't 'cut it,' ... well... for 'reasons'
So for 'the experience' ... well... did you ever have the pieces of the 'puzzle' fall into place almost immediately, in that Archimedian like 'aha moment' (I think they say he said 'eureka'... but no matter.)?
No doubt... you did. And no doubt... many times it was something a particular someone mentioned.
So back to YouTube... well that's happened to me...? maybe... a couple of times, in the last two decades... and more so in the last decade... watching YouTube vids, as better YouTube tech content grew.
But... it happened almost weekly when I was in school. (There was always a prof... and sometimes a grad student too... that had such a unique conception to offer... an 'angle' if you like.)
And that's not something that's going to happen... at least IMO... with a bench full of Alitech, downloaded textbooks, and weekend warrior, regimen.
Naw!... you say.
Okay... let's see what AliEngbot AI/2 comes up with.?
But, I won't be crossing any bridges that those things designed... when it comes to it.
?

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I'm a bit of an instrumentation nerd these days. I rarely need to do RF measurements at near-DC frequencies (that is < 2 GHz) but I can't afford a VNA that will cover my ranges of interest.? I have a PocketVNA, NanoVNA H4 and LiteVNA 64 that sort-of work OK above 3 GHz, and some can go to 5.7 GHz with limited accuracy, but my budget won't stretch to the sort of kit I need to cover 5.7, 10, 24, 47, 76, 122, 134, 241/248 GHz and higher.???

I have a counter that will go to 20 GHz, HP and Agilent spec-ans that cover up to 50 GHz, signal generators to 27 GHz, calibrated diode noise sources to 6 and 18 GHz, plus gas discharge sources to 40 GHz, but there are serious gaps that I need to address without spending all my pocket-money allowance. All of the kit is very much second-hand and low cost.

I have some slotted lines for several frequency ranges to 40 GHz, and I'm building adaptors to cover other ranges using the standard Marconi Instruments slotted line carriage. I'm working on some machining slotted line rigs for some higher frequencies so I can make precision measurements at 24 and 47 GHz.??

I can do length/diameter measurements to within a micrometre, so wherever possible, I'm using tools that work from length or angle measurements (slotted lines for coax/waveguide, sliding shorts, sliding loads, cavity wavemeters, attenuators) without relying on any transfer standards or calibrations other than the attenuators. I can do pretty much whatever a VNA can do, but it takes at least 20 times as long.

I have some Rubidium sources plus a few very well-aged Morion quartz DOCXO devices in anti-vibration and insulated mounts, which are trimmed against (but not locked to) GPSDO sources, which are less than good over periods of less than a minute. I use a really neat BG7TBL FA-2 8 GHz reciprocal counter that gets to 11 digits quite rapidly.

My HP ESG series signal generators are noisy, but locked to GPS, but for higher frequencies I use multipliers and comb generators driven from 100 MHz OCXOs phase-locked to the Morion references. I have some Klystrons, various high power magnetrons, Gunn sources and even a couple of backward-wave oscillators, plus a range of YIG oscillators and YIG filters. For lower frequencies I have a super BG7TBL signal generator that was excellent value.

I don't have any precision voltage standards other than a Fluke 8845A 6.5 digit DVM which is still in calibration.

I have a Hutales LCR meter, but I rarely need to measure discrete capacitances or lumped inductors. Mostly I'm measuring microstrip, grounded coplanar waveguide and coaxial or simple cavities.

I have an HP 8970B noise-figure meter to work with the various noise sources.? One source is still in calibration and I use it to calibrate the others, but I'm working on some proper hot/cold sources using cold sky and a heated absorber panel as references, to avoid having to rely on transfer standards.

For RF power measurement, I rely on a range of thermal and diode heads, mostly HP/Agilent/Marconi, and some good quality power attenuators (eg Wiltron, Narda, H&S, HP) including one that's good for 100 W for DC to 18 GHz, and vane attenuators for various different waveguide sizes, plus some stepped attenuators.? I have some Narda/HP directional couplers, and some home-made directional couplers with calculated coupling and directivity based on precise diametric and linear measurements then calibrated against known good attenuators and power meters.??

I'm working on a proper DC-replacement calometric thermal flow power meter using only DC voltage and current measurements, so that I can use it to calibrate my other instruments.

For other RF measurements, I'm building some Fabry-Perot open resonators to make dielectric permittivity and loss tangent measurements, and a range of split-post dielectric resonators for the same function.? Those are all low-cost and simple enough to make in a home machine shop, and are mostly self-calibrating.? I'm also making some coaxial dielectric test jigs, again using precise linear and diametral measurements based on physical length standards accurate to better than 100 nanometres and a granite surface plate and Mahr gauges accurate to better than a micrometre.

I have made some precision capacitors in the past, with guard rings to eliminate fringeing, but they aren't much use above a few MHz.

I have some commercial EMF measuring heads (EMCO) and I've made a TEM cell to calibrate them, along with some home-made sensors.? Over the winter I'll be making a much larger 50 ohm open TEM cell with an internal septum and a volume of 2 x 1 x 0.7 metres.? Again, this is self-calibrating using precise dimensions, leaving only RF power measurement to be defined. The plan for that is to review a range of the tinfoil-hat-wearer EMF measurement devices in known fields so I can make a video debunking (or otherwise!) their performance.

For magnetic fields, I only have some Helmholtz coil pairs to generate calculated fields, and some Hall sensors.

For vacuum measurements I have some Pirani gauges to measure from atmospheric down to 1e-7 atmospheres and Penning gauges good to 5e-11 atmospheres (using a radioactive beta source, big magnet, 2.3 kV accelerating voltage and using the resulting spiral electron flow as an analogue of pressure).

I don't have anything to measure optical or RF power above about 100 GHz (yet).

I have a dual-tube Geiger counter for beta, X-ray and gamma.

I don't have anything to measure voltages greater than 3kV although I have a variable power supply running up to 50kV which has a meter.

I have a truly terrible digital scope with recording facility and a load of functions including Fourier analysis, but it only goes up to about 200 MHz, so I only use it very rarely.?

I plan to make a quadrupole mass spectrometer for gas analysis measurements and lots of testgear related to making thermionic vacuum devices such as magnetrons and gyrotrons.

My entire lab philosophy is based on using cheap, solid, ancient technology and calibrating where possible by transfer from calibrated length/weight standards, plus a calibrated DVM and thermometers calibrated with known melting/boiling points and my frequency standards ultimately referred to GPS time.? "Budget" is relative of course, I choose to waste my pennies on testgear and machines instead of radios, fast cars and high living!

I tend to agree with David on S/N ratio of this yutube stuff. There's plenty of smart clever people putting stuff up, but the yutubes seem to be way too long - probably to keep viewers on-site to maximize ad revenue. Most stuff I've seen takes maybe ten minutes to a half hour to describe or explain something that could be written on a single page .pdf - maybe two pages if there are pictures or diagrams needed.

There are some good to great ones, where you really do want to see video of things being opened up for discovery of what's inside and such, but even then, the run time seems way longer than necessary to get the picture, so to speak.

Ed

In my experience there is a great deal more noise than coherent signals on 'YouTube" when it comes to anything of a technical nature, especially when it comes to R.F. design for some reason... on the very rare occasion that I have encountered anything of apparent value there, the actual practical value is nullified by the length of the video; i.e. compared to reading a book where one can easily pause to study (e.g.) a diagram on the page - or indeed skip a few pages due to irrelevant material or material one already knows, on YouTube one has to mess around with pausing the video, maybe repeating a segment of it over again, or finding the point where the material is of interest. I find it to be totally impractical to use this as a media for the subject matter which we are? involved in.

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F.C. Trevor Gale

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I very much agree with the comments on the SN ratio of YouTube but there are, thankfully, exceptions - IMO one of the best is Alan (W2AEW).? To me he seems to consistently provide good information in a accessible format without a lot of filler.

Hal

On Fri, Dec 22, 2023 at 09:28 AM, Roy Thistle wrote:

Can't say where other's went to EE school; but..
IMO... and in my university... it might have been different.
I'd say that tech talk on YouTube is mostly edutainment (nothing wrong with that for entertainment)
And pop-engineering books (even with a bit of math) are not very good... whilst... textbooks have gotten bad as well too.

It is hard to replace a good instructor. However, it can be tough to figure out which schools have those good instructors. Most of my electronics knowledge is a result of the public library system.?

Discipline in learning can be difficult. I have the fortune to be very single-minded when i want to know something. After high school, a lot of people assumed I was in college because I had a backpack that always had a textbook, grid paper, and a scientific calculator in it that would come out at every break and at lunch. At home, I did a lot of experiments in RF and other circuits. I experimented on myself to see what was the level of current was at the threshold of perception in my hands and arms (in case of accidental contact while working) and incidentally measured the approximate impedance of flesh (past the skin) at 50 to 200 ohms. Except for a 'scope (bought used) and a VOM (built from a Radio Shack kit), I designed and built most of my own test equipment.

If a book didn't give me an "aha!" moment, I'd find more books on the same subject, make a lot of drawings, do some lab experiments, and think a lot about it.
?
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Tenure can also be based on the factor of having enough money that one can perform an universal gesture of love and kindness to the university. Especially effective when the finger is erected while seated in an exotic car or a first class seat.

Can be done. Has been done before.

/me did it. It felt great.

With best regards
Tam HANNA

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On Tue, Dec 26, 2023 at 08:31 AM, Dr. David Kirkby, Kirkby Microwave Ltd wrote:

Tenure will be based on publications -

Unless you're applying to Harvard it seems :-)

Morris (who was non-tenured)