Re: Diagnostic software for uBitx #ubitx


Tim Gorman
 

Heathkit used to do this with some of its kits oh so many years ago.
Then the concept seemed to disappear into the ether.

Congrats to you for newly discovering the concept again. It is a
concept that is of huge benefit to the newcomer to electronics that
doesn't have the resources to build up a test bench right off.

tim ab0wr

On Sun, 29 Apr 2018 05:44:30 +0000
"Hans Summers" <hans.summers@...> wrote:

Hi all

So far I have to say the Han's QCX concept is really
neat. It uses 6 passive components and provides an
on-board DC, AC/RF meter, RF power meter, frequency
meter and signal generator. Brilliant.
That coupled with the measuring functions pre-loaded
in software and an expected list of values seems the
best value for money in debugging a radio's circuit
and wiring.
Thanks for the nice comments about the built-in test equipment and
alignment procedures in the QCX transceiver kit
http://qrp-labs.com/qcx ! At the time I developed these features I
had no idea that they would create so much excitement.

I had never seen a kit with built-in test and alignment equipment
before. But I have personally in the past have built kits or
projects, and got all the way to the end - only to find what seems
like a very complex alignment procedure, or I need some other piece
of test equipment for it - and relegated the kit to the shelf for
seemingly infinite postponement.

The QCX concept was originally designed for the YOTA 2017 summercamp
buildathon hosted in UK by RSGB in August last year. I could imagine
a room full of youngsters finishing the assembly and getting stuck
for want of equipment to use for an adjustment procedure... or
fighting over one set of equipment the organizers had brought along
for the purpose. How much nicer, to have all the equipment built-in,
along with firmware assistance to guide you easily through the
process! In the QCX it's a Band Pass Filter peaking adjustment, then
the I-Q balance and phasing adjustment to get best unwanted sideband
suppression. It makes alignment simple. Literally just a few minutes
is all it takes to adjust it for around 60dB unwanted sideband
cancellation.

Once that far... It was a relatively small further thought step to
say, well why not add the DVM (which can later be jumpered to the
power supply input to allow an on-screen battery icon, useful for
portable use!), RF Power meter, frequency counter and signal
generator. It took very few additional components to add these, which
are useful if the assembly needs debugging, and even just for general
purpose use in the shack.

I'm really happy these built-in test and alignment equupment features
have turned out so popular!

73 Hans G0UPL
http://qrp-labs.com

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