Cheers!

--
Raj, vu2zap
Bengaluru, South India.

I learned something new from this slideshow:

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Electronics 101, with a lot of not-such-good advice.

Boat anchors are fine, if you know what you're doing - you take as much of a chance buying Chinese as a boat anchor.? (I have both boat anchors and Chinese, and have not been stiffed on either.)? If you buy from the $25 or lower "get rid of" pile, you should EXPECT it not to work, and be ready to do research and repair.? Sometimes they can't be repaired and are only good for parts - although obsolete parts sometimes take some research to replace, but parts can still often be found.? There ARE manuals and schematics available for many boat anchors available... I would warn that troubleshooting complex equipment can be time consuming and rather difficult (expect caps to go bad, and sometimes resistors change value).? I would leave the $5 pile alone unless you like taking long shots.? (If it's more than that, you might get lucky... if it can be tested before buying... do so.)? Oh,? and just because it looks 'high-tech', doesn't mean it's something you could find useful.? A logic analyzer is great for some older equipment, but not always that useful for newer stuff!

If a DVM won't do 120vac (standard house voltage for the US), don't buy it... it's worthless.? There are perfectly good DVMs available that are under $100 and that's one instrument you shouldn't ever skimp on.? Radio Shack is still in business the last time I checked, although only online.? They had really decent meters (and I loved the 'pen scope' I used to have, before my original shop was torched).? I found them reliable and comparatively rugged (don't try to measure a high voltage DC with strong AC component... few meters like that combination!).? (You should also know their limitations and what the tolerances are that count!)

Soldering iron... the better the iron, the more you'll appreciate it.? Temp control and 60 or more watts is a good combination that quickly become important.? It's not fun trying to solder a ground plane with a $15 cheap-o.? Soldering skills are critical - know what you're doing!? (Butane irons get addictive, by the way... and I've had really good luck with them, although they generally don't last as long as a decent electric one.)

Scopes are an important tool, but you also need to understand them and how to use them (a digitizer with adequate bandwidth is nice, but there are many times that an analog is much easier and effective and worth the price - and? a low bandwidth digitizer requires thought and skill to effectively use, within its limitations).? For me they're indispensable, but I've used one for over 40 years!

If you DO buy something that requires software to operate, scan the he** out of the software before you install it - and if you can get an older version, I'd use that first (more likely that if there is something bad, it will be found).? The authors often DO like Windoze, and you WILL encounter viruses and malware (or back doors), especially if they come from, shall we say, a certain country.? If the software comes up clean, it can be really useful... again within its limitations.

An antenna analyzer is very useful... can often be used for far more than antennas (such as checking values of caps or coils at frequency).? Along these lines, the old "grid-dip" (or modern equivalent) meters are very useful.? I could name several other pieces that would be lower on the priority list, but great for the bench... many can be home-brewed for little or no cost.

I stopped reading after a couple of dozen slides or so... I don't know how important the author considered a decent signal generator.? There are ones available in kits that are very reasonable... and work great when combined with (for instance) a step attenuator.? I salvaged a decent attenuator out of a (partially) burned signal generator and combined it with such a kit, and since the software for it that I run is open source (under Linux) and well-known, I have no problems.? Kits are great... a lot of fun to put together (if you have the time).? If you work on radio gear, you really should consider something like this!

IMPORTANT POINT: Keep your equipment in a reasonably temperature-and-humidity controlled area, and keep it cool!!!? The equipment was meant to be in a low humidity environment and most were designed to stay in temperatures under 70 degrees or so!? Heat is the killer of electronic equipment by a huge margin, with 'mistakes', and power surges/lightning, and so on a distant second!? (DVMs are designed for a wider environment - at least the better ones.? Same goes for SOME portable gear.)? If you buy boat anchors, consider improving the ventilation on the device, adding fans and so on.? The cooler and more stable the temperature and humidity, the better!

Finally, find someone in your area who is competent and willing to help - a decent (patient and listening) and experienced Elmer.? Someone like that can help evaluate gear, help with developing a calibration protocol or method, and so on.

(Qualifications: Ham since 1980, General Radiotelephone License, owned Robotics/Industrial Electronics shop for 16 years and repaired commercial two-way radios and consumer electronics before that, with a great many hours fixing boat anchors and so on - including precision laboratory equipment.)

Bob

N4FBZ

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Ask that of the original poster.

Thank you so very much. For myself this one post would make it worth joining even if no one ever helped a fellow Han and the the whole group was grumpy old men. But NO, this is just the opposite. A bit of good humor goes a long way even on a good day.?
Qualifications:
electronics study, build, repair, design, & modify since 1950.?
USMC trained telephone, radio, fader, & test equipment use/calibration.
Design/build 2 kw amp using military salvage dental equipment power supply for K4MCL/N0AMC Albany, Ga.?
IBM trained computer hardware, software, and senior programmer vi editor.

Future:
7 inch display for ubitx v4 with wireless remote control using no machine/teamviewer software.?
System boxed for use with Terratrike when trail riding.?

Frank KJ5WI, the wild Indian

I disagree with his hate for cheap/free Harbor Freight multimeters.? Sure they're not nuclear grade accurate but for a ham on a budget they have their place.? Besides, it is most likely more accurate than the tolerances of the components being tested.
--

I've got about 10 of the HF dvm's lying about,
I do have better, but the HF are generally the first dvm I reach for.
Mostly because there is likely to be one close at hand.

I've never found accuracy to be an issue, they are extremely accurate.
A capacitance range would be nice, and auto ranging can be handy too.
Probe wires separate from the probes after a few months of hard use, easy to fix.
My primary issue is the HF dvm's seem easier to destroy than
some of the other dvm's, doing stupid stuff like having the dvm set to ohms
when looking at a voltage source.? Especially when??probing stuff out in the rain
at night when the pickup has an electrical failure or something.? And in that case
it would always be the HF, since I have one in the glovebox.

When I do pop one, it's a very cheap $1.00 (on sale) lesson.
Not a $100 one.

Good idea to color the business end of the knob so you don't accidentally?
have it turned 180 degrees from what you want.

Jerry, KE7ER
??

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One thing to keep in mind with a DVM is it’s safety rating. Should a transient voltage hit the meter you want the meter to be able to interrupt the internal fault and protect the user with adequate insulation in the probes, leads, and case. At minimum you should look for a Cat 1 rating. Here is some info from Fluke>>

I agree with Jerry -- the Harbor Fright DVMs are the ones I reach for first.?

?

Like Jerry, I do that because they are cheap crap and I don't care if I blow one up.? Having set fire to the same Fluke 77 three times, I agree, blow up the cheap junk first.? I will mention that Fluke has always been more than generous on repair or upgrade replacement on my 77s.? So they're high on my "use vendor again" list.?

I'll also add -- the ME-77C/U mil-surplus multimeter (google iot) is on my "maybe you don't want to buy this again, because it uses a $75 unobtainium 22.5 V battery that can't be replicated from current sources.? But if I could get one to work ... I'd put it out on my Field Day table for testing stuff.? And then I'd get a few more.

Why?? Because everybody around here (Austin TX, within shouting distance of all the airbases in San Antonio) we see a lot of these in the junk boxes at swap fests, and they're kinda the 1950s version of the crap Harbor Fright DVMs.? Most of the gentlemen who used to use these have passed, but there are a few of us who still recognize classic utility.

73
Jim N6OTQ

PS -- Good off-list stuff at <https://armypubs.army.mil/>

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The Radio Shack unit I had (the only meter I ever destroyed - by the output of a 50hp PWM servo drive that had too much of an AC component on a DC voltage) was really rugged (I replaced it with the same model).? When the thing blew, it popped internal fuses and shut down the drive, and the only thing that happened was smoke coming out of the lead holes.? Needless to say, I was one unhappy camper about that.

The better units often come with a plastic (insulative) cover or sleeve which helps to contain things like that - they're always a good idea to have on.? (Flukes are pricey but awesome units, I could never afford the model I liked, which had a computer interface.)? I think that sleeve helped to contain the 'pop' (It was quite... audible).

Talking about having equipment blown up...

I did have a scope blown up one time - working on a CNC machine and was doing some special tests in the control.? Stupid nut of an employee pulled the tag from the breaker and flipped it on - sparks and smoke everywhere (fried what was left of their control too).? The company refused to do anything to the stupid jerk, and refused to replace the (portable) Tek scope he destroyed - he almost fried me too (I did get a small burn on my shirt from a spark).? His argument "I need to punch some holes NOW!!!" - even though the machine was NOP and tagged out.? That was the last time I went in that plant.

(The company said because nobody else saw it, that they wouldn't do anything about it, it was my word against their employee!? They also implied that they were going to charge me for a replacement control - even though the jerk did say out loud in the presence of others "but I had to punch some holes!!!")

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I didn't have a lock... and the company didn't provide one - considered a tag to be sufficient.? That was back in the late 80s, as I remember.? Tagging and locking were considered "Government regulations harming my business!!!" by a lot of companies in this area.? It sometimes caused friction.

BTW... it's offensive to add insult to injury.? It was THEIR responsibility, or their employees, to respect the tag... not my 'fault' because one was too stupid to think or read.

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(Laugh) I know what you mean.? Most of my customers didn't care, as long as they couldn't be held liable or would have to pay out of pocket.? I was just a service provider, not an employee so I really didn't count.? Something happened to me... unless they could be sued, it might mean not having to pay for the work.

I could tell all sorts of horror stories about places I went in, but that's not even close to topic.

kj5w Frank.

A well spent $10 insurance policy for electric & electronic as well as anyone doing walk in repair or maintenance.?