Re: A word of advice


geoff M0ORE
 

I have to agree 100%. I have had one kit where there was a problem with the board and I contacted Hans direct on that.

There is no point having a bench full of test equipment if you don't know how to use the results that it gives. No scope will tell you that the fault is due to C???, you have to be able to diagnose the symptoms and test results.

A lot of practice on equipment that is working will build up confidence in the testing, no point learning on a kit that has never worked.

We were all beginners once and have built up our skills over many years. I was fortunate to work in an environment where I had to repair faults ( sometimes after being called out in the early hours ) with the clock ticking and the customer  or control centre breathing down my neck to get the systems back.

Start on the easier kits to build up the confidence and skills.

On 23/01/2021 12:05, howard winwood G4GPF wrote:
Groups like this  tend to be a gathering point for those building and troubleshooting kits offered (in this case) by QRPLabs.
One thing I have noticed, and this applies to a lot off other similar groups, is that there appears to be very little advice on who should/should not be building these kits.
I say this because of the obvious lack of knowledge/skills in even basic electronics that some builder seem to have.
Now, that is not to belittle anyone, we all have to start somewhere, BUT these kits are not really aimed at the beginner for a variety of reasons.
1/ Basic electronic knowledge of components, Ohms law.
2/ Basic soldering skills
3/ Basic set of tools
4/ Basic test gear
5/ Ability to read a simple schematic circuit diagram.
I have noticed on this group and on the microBitx group, that some people (usually with less than even basic knowledge) think these kits (I use the term kit loosely for the microbitx kits) should work with very little effort.
Sadly, as most experienced builders know from experience, this is not the case.
I am going to offer those who may be tempted to get into kit building, some advice based on 50+ years of tinkering with all sorts of electronics, not just in Ham radio.
How do you judge the quality of a kit?
This one is quite simple, look at the documentation.
I will say at this point QRPLabs have some of the best and most comprehensive documentation out there, and would recommend their kits to anyone who has reasonable skills in electronics.
The standard by which kits are judged goes back to the days of Heathkit, superb kits with superb step by step instructions, but certainly not cheap.
So! what level of competence should a prospective kit builder have?
To start with, a basic knowledge of components, resistors, capacitors, semiconductors, inductors.
I would have thought that most radio hams would have this knowledge but it seems I am wrong.
To be able to identify and test resistors and capacitors is a start and to have a basic understanding of their function.
Basic soldering skills are essential, you should not be practising your skills on an advanced kit like the QCX.
After 50+ years of radio building I can still get a bad solder joint, because my eyes don't always pick it up straight away, but I always go over my soldering with a magnifier and ANYTHING that looks suspicious gets a second go.
Basic tools are essential, go for the best quality you can afford, they will last you a lifetime.
a small selection of screwdrivers, side cutters, long nosed pliers to start with.
Some basic test gear such as a Digital Multimeter, and it does NOT have to be expensive. You do NOT have to know the voltage down to the 3rd,4th or 5th decimal place.
Forget things like Oscilloscopes, signal generators, Spectrum Analysers and other fancy test gear for now, they can come later when you know what they can be used for (AND how to use them).
The ability to make some basic sense of a circuit (schematic) diagram, otherwise you are on to a hiding to nothing.
This is where the likes of QRPLabs show their mettle, by not only providing very detailed construction  notes, but also detailed set up instructions with a lot of the hard work taken care of by being in the software
and accessed through the display.
Unfortunately, by making it relatively easy for Joe Bloggs to successfully build and get working, these kits, it will attract those with lesser skills to attempt something that MAY be beyond there current capabilities.
I would not dissuade anyone from having a go, but would advise to start on a few much simple projects, there are plenty of cheap soldering skill kits on Ebay that will get you going and get you skills (soldering especially) up to scratch
before you tackle something more adventurous.
Unfortunately groups like QRPLabs will by definition attract those who have had problems, and where would we be without such groups to help iron out such problems?
It is where the problems are caused, not because of the quality of the kits, but caused by the lack of skill/knowledge/understanding of the constructor.
Because it is the problems that get highlighted, that the casual observer can get the impression that these kits are not always up to scratch.
When, in fact it is the constructor that is not up to scratch.
I am not trying to put anyone off building their own gear, it is massively rewarding to operate something you have put together yourself, and would encourage anyone to have a go.
BUT, be prepared for disappointment, there are no guarantees in this game.
The BEST piece of advice I can give if you are starting out in the world of radio construction is to mate up with someone who has been doing it for a while and and can offer advice and possibly test gear you may not yet need/have.
Groups like this really are helpful but unfortunately remote, so is much harder to diagnose and get information across.
I am not trying to put anyone off, just offering some advice on being realistic when you tackle kits like these.
Just remember, there are times you just have to put things down to experience and move on to the next project.
You can always come back to the projects in the "to finish one day" bin. ( I have lots! LOL)

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