kristoff wrote:
Well, I have this discussion a number of times.
(I man a infobooth to promote amateur-radio at FOSDEM -a yearly
conference on open-source development in Brussels- so I get to explain
this quite a lot)


In essence, that is not the problem with the exam itself.


When explaining to people why you need to do an exam for amateur-radio,
I compare this to a drivers-license.

A drivers-license is to show that you are technically capable to drive a
car on the public road in a way that is safe for yourself and others on
the road.

This is very similar to the the amateur-radio exam: it is to make sure
that you have sufficient technical knowledge to transmit without
interfering with other radio-users and to make sure you do not blow up
yourself.

The only additional element here is that we are not only allowed to
drive a car, but to also build one ourself; so, you have to show you are
technically able to build a basic model of a transmitter.



So, in essence, the exam still serves it goal: allow all users of the
radio-spectrum operate without to much "bumping into each-other".



But there is very different problem:

The problem is that radio-technology nowadays is nowhere near the
technology when the exams where conceived.

However, that does not apply to antennas, the current topic.
For antennas, their matching, and the losses, the theory that you
(should have) learned for your amateur radio exam still applies today.

Maybe you should listen/join the ZX net, every Sunday 9AM on 3603 kHz,
where this topic is patiently explained time after time by the moderator
Bob ON9CVD. Or check his website or send him a mail asking for some
of the talks he has held their on the topic of antenna matching.

Hi Rob,



On 22/07/2020 11:09, Rob wrote:

The problem is that radio-technology nowadays is nowhere near the
technology when the exams where conceived.

However, that does not apply to antennas, the current topic.
For antennas, their matching, and the losses, the theory that you
(should have) learned for your amateur radio exam still applies today.

Euh .. why would this not apply to antennas?



Modern technology allows you to do a lot of new things that are not at
all covered in the exam:

Antenna-related technologies like spacial diversity reception, phased
antenna-arrays) have become easier to implement with SDR.
Using signal-processing, you can much easier modify (e.g. delay) a
signal, and you can change that dynamically and -if needed- several
times a second.

I did talk to somebody at the GNURadio devroom at FOSDEM last year who
wanted to make such a setup to track weather-satellites with a setup
with three fixed antennas and three phase-locked SDR receivers.



The exam mentions antenna-impedance and antenna tuners, but in how many
clubs has there been a workshop on how (say) the hardware and software
of an magnetic loop automatic antenna-tuner actually works.
(I know of one club where this has been done .. :-).


Same thing for tools.
In how many clubs has the topic of (say) antenna simulation tools.
I went to a club where there was a presentation on this topic. I was
actually the only person who took the time to try this out myself
beforehand and who had a real antenna with me.
When after the presentation, I proposed "you know, why don't we do a
workshop on this, say 5 people. Everybody brings an antenna and we can
all together try to create a model of it so we can really learn the tool".
The responds was ... euh .. overwhelming. (sarc)


I've been trying for years now to find somebody who can give a workshop
on how to design a path-antenna. No success.


The same thing for physical design technology (3D printing, CNC milling,
....) for antenna applications.


There now even is technology where an FPGA on the antenna is use to
connect / disconnect parts of an antenna and to control the polarisation
of the antenna.
You can actually do it so fast that you can use it to encode bits of a
digital transmission in the polarisation of a signal. (apparently, 5G
will use this).





Maybe you should listen/join the ZX net, every Sunday 9AM on 3603 kHz,
where this topic is patiently explained time after time by the moderator
Bob ON9CVD. Or check his website or send him a mail asking for some
of the talks he has held their on the topic of antenna matching.

Thx I will contact him.

Perhaps he can help me to understand how an antenna system actually
works from a physics perspective.


73
kristoff - ON1ARF

Hi Jeff,



On 28/07/2020 11:07, Jeff wrote:
The problem is that radio-technology nowadays is nowhere near the
technology when the exams where conceived.

However, that does not apply to antennas, the current topic.
For antennas, their matching, and the losses, the theory that you
(should have) learned for your amateur radio exam still applies today.

Euh .. why would this not apply to antennas?

I think what the OP is trying to say is that antenna theory has not
changed over the years, and Maxwell's equations, transmission line
theory etc. still apply and have not been superseded.
There has been no great leap in antenna technology compared to other
branches of radio communications. What was good 50 years ago is still
good today.

Well, I did use the term antenna *systems* with a reason :-)


But in essence, that's not the point.

This message-thread is actually a reply to a message saying that the
exam has become to easy.

The way I see it, it is not the 90 % "operator" hams that will determine
the future of amateur-radio. Operators follow the technology as it
become available (DIY, commercial) and, in that sense, how easy or
difficult the exam is not that relevant.

What is important are the 5 to 10 % technically-minded part of the
amateur-radio community, the people who are busy building and designing
things, either creating new devices or combining devices to build
infrastructure in a novel way. (and, to be honest, I consider this NG
part of that).
For me, that is the group of people that will make amateur-radio survive
in the 21st century.



20 to 30 years ago, most devices consisted of one type of technology,
and that was either "analog" or "digital". (with some exceptions, like
using a PC to do RTTY)
But in 2020, almost all devices are now a mix of analog, digital-control
and digital-processing technologies, that might even use a LAN or PAN
network to connect to a backend-infrastructure and do data-processing or
even ML.

(See the examples of the combination of antenna-technology with fields
of technology like like digital-control and digital-processing in the
previous message.)


And that aspect makes things now completely different from technology 20
years ago: as devices have become a mix of different technologies, so
has become the requirements for people interesting in developing new things.


So, yes, I agree. Antenna-technology by itself is one of the fields that
has changed less then other technologies; but antennas + digital-control
+ digital-processing + simulations + "data" + whatever is nowhere what
was possible 20 years ago.



Anycase, let's hope that we can find a way to get sufficient
technically-minded people from ham-community interested in taking the
next step so the hobby can survive in the 21st century.


(but as we have now gone quite off-topic here, I propose to close this
discussion)



Jeff

73
kristoff - ON1ARF

Hi Jim,




Just a quick reply.


On 30/07/2020 20:09, Jim H wrote:
For me, that is the group of people that will make amateur-radio survive
in the 21st century.

Surely you're kidding... or didn't think it through well enough.

It takes the other 90 - 95% (using your 5 - 10% figure) to create the
critical mass needed to keep the equipment manufacturers in
business... without which the hobby/service won't survive.
Even if the 5 - 10% make their own rigs, we wouldn't have a critical
mass of licensees to lobby successfully to keep our frequencies if our
ranks were to consist of only the 5 - 10%.


I think you do not really understand this issue here.

This is not about boxes. "making your own rig" and "designing new
technology" are two completely different things:

- You can build your own radio, but just use it do plain old CW or SSB.
- You can use a commercial rig to try out if by using a different
FEC-system you can make GMSK-based codec2 digital-voice more robust to
slow-fading then FM on 10 meter Es DX.



By definition, amateur-radio is "a scientific / technical hobby that
deals with everything related to radio, radio-communication and
radio-technology".

If you equate technology to just the device, then you're a user.
If you understand and are able to manipulate the ideas behind that
technology, then you are can determine the future of that technology,
and of amateur radio!

That is what the 90 / 10 % is about!




73
kristoff - ON1ARF