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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
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
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
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
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
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)