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Old October 29th 11, 03:05 AM posted to rec.radio.amateur.antenna
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Posts: 117
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"Owen Duffy" wrote in message
...
"Sal" wrote in :

...

Say, after following the link, above, I just took a look at that
AIM4170 web site and it looks like it's more trouble to get it up and
running than most things. A lot of the steps are left to the
imagination ... or they assume a whole lot about what potential buyers
already know.


Sal, I bought an AimUHF, and it worked fine out of the box.

I suspect that the problem that most hams encounter with analysers and
VNAs is that the knowledge of basic complex numbers, AC circuit theory,
transmission lines, and antenna systems does not 'come in the box'.

If acquiring such a thing is the stimulus for expanding knowledge on
those topics using the box as a learning aid, that is great. But to
many, they are safer to just treat it as a VSWR measuring device.

I am staggered by the popular advice offered to newbies who ask 'why is
my VSWR high' on eHam and QRZ to borrow an analyser. The advice appears
to offered mainly by people who don't understand the instruments, and
possibly have never used them effectively.

A classic example is the advice to connect the instrument at the shack
end and tune for resonance, for as everyone knows, "an antenna just
ain't gonna work any good unless it is resonate (sic)".

The getting of knowledge just isn't a priority in a world of instant
gratification.

Owen


Thanks, Owen,

I understand the world of complex numbers and vector impedance
well enough. My concern is whether I can make the thing work with
what appeared to me to be a dearth of hookup instructions.

How did you know what cable(s) to order? Are you operating with
a software COM port or do/does your computer(s) come with a
hardware COM port?

Anecdote:
Right after Field Day, for which I am the club Chairman, I followed
a fellow club member's suggestion to try to get a network logging
program running in preparation for next year. No dice. Hours
wasted.

I followed many conflicting or wrong instructions; the best I managed
was to get the two computers to each acknowledge the existence of
the other -- but no more. No sharing of information and darn little
help from the maker of the software, who assumes we are are all
networking engineers.

Moral:
So, with the bitter taste of failure still fresh, I'm not really ashamed
to act shy around this next (possible) installation.

As I told Ian, I'll try the software and see if it radiates warmth. It
needn't be hot ... just not ice cold. :-|

"Sal"


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Old October 29th 11, 03:24 AM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
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"Sal" wrote in :


....

Thanks, Owen,

I understand the world of complex numbers and vector impedance
well enough. My concern is whether I can make the thing work with
what appeared to me to be a dearth of hookup instructions.

How did you know what cable(s) to order? Are you operating with
a software COM port or do/does your computer(s) come with a
hardware COM port?

The AIMuhf connects to the computer by USB, just a mini USB IIRC, and I
think they supplied a cable.

....
As I told Ian, I'll try the software and see if it radiates warmth.
It needn't be hot ... just not ice cold. :-|


The software is a very important element.

In my experience, the software with these kinds of things is
amateurish... but usable.

I also have a TecTec VNA, but I avoid using it if I have something else
that will do the job, and the AIMuhf is usually better if a one port VNA
is up to the task.

You will see plots from both of those in the article
http://www.vk1od.net/antenna/7MDipole/7MDipole02.htm .

There are other ham grade VNAs, I haven't researched them deeply, some
may be kits or homebrew that leave you challenged to find some of the
parts.

Owen
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Old October 29th 11, 04:49 AM posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Jul 2011
Posts: 117
Default Trap antenna


"Owen Duffy" wrote in message
...
"Sal" wrote in :


...

Thanks, Owen,

I understand the world of complex numbers and vector impedance
well enough. My concern is whether I can make the thing work with
what appeared to me to be a dearth of hookup instructions.

How did you know what cable(s) to order? Are you operating with
a software COM port or do/does your computer(s) come with a
hardware COM port?

The AIMuhf connects to the computer by USB, just a mini USB IIRC, and I
think they supplied a cable.

...
As I told Ian, I'll try the software and see if it radiates warmth.
It needn't be hot ... just not ice cold. :-|


The software is a very important element.

In my experience, the software with these kinds of things is
amateurish... but usable.

I also have a TecTec VNA, but I avoid using it if I have something else
that will do the job, and the AIMuhf is usually better if a one port VNA
is up to the task.

You will see plots from both of those in the article
http://www.vk1od.net/antenna/7MDipole/7MDipole02.htm .

There are other ham grade VNAs, I haven't researched them deeply, some
may be kits or homebrew that leave you challenged to find some of the
parts.

Owen


Thank you, Owen. That web page was all very instructive.

"Sal"


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