John and Mary Powell wrote in a different thread:
>Is there a body of opinion out there that considers the above subject has gone
>on far too long, or got out of hand. To me it appears as if academic
>intransigence has got in the way of the Reflector dealing with it's core
>business. I noted an earlier plea for an end to of this uninteresting topic,
>which evolved from a simple enquiry as to accuracy of the Bird 43 Wattmeter.
>
>Cheers
>John Powell. ZL1BHQ
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>http://lists.contesting.com/mailman/listinfo/amps
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>
>
>
I'm not keen on a thread being split up for no good reason. Someone
started this thread with the title 'Measuring RF Power' and so why
ZL1BHQ starts a new thread 'MEASURING RF POWER' complaining about the
original subject going on too long is beyond me. Most people use mail
clients that that are capable of following a thread, and collapsing that
down to one line. Most mail clients can be configured to automatically
delete something with a particular title.
So if you don't like a thread, just collapse it to one line in your
mail client, or do an automatic deletion, so it takes up zero space.
Hence I decided to reply under the original thread, not the new one that
has been started for no good reason.
By starting a new thread, you have of course screwed it up for someone
who was choosing to ignore the thread - now they have a second one to
ignore. It also means when it is archived, someone interested in the
subject will not see all the posts if they follow the thread, since it
got split. Hence I'm not replying to the new thread, but under the old one.
Now to address the comments of ZL1BHQ:
I think you are right to suggest there is a body of opinion that
consider the above subject has gone on for far too long. Those might include
1) People who want just simple things, and don't wish to learn any more.
2) People who were wrong, and don't wish to admit it.
Sure, the thread is technical in nature, but less so than other threads
that have appeared on here before, and with less mystique about it.
However, there is also a body of opinion that thinks it is:
1) Relevant to amplifiers. They do produce RF power, so measuring it is
a pretty good idea.
2) There is a 22.5% difference between the mean and RMS values of power,
so the replies by some of "who cares anyway" seem odd, when there are
quite a few who would care about a 22% difference in power levels.
3) Within their grasp to understand.
To follow the paper written in Laymens terms
http://www.eznec.com/Amateur/RMS_Power.pdf
you need the level of maths and electronics any radio ham should be able
to handle if they put their mind to it.
To understand the formal definition of RMS (using integration) a level
of mathematics that I had learnt at school by about the age of 16 will
suffice.
4) A new topic discussed, and not the same old arguments being used
about a topic that comes up again and again, year in and year out.
It's also possible the topic has greater implications that some of you
think. Someone wrote to me and said
"Several years ago I did not realize, like many others, that there was
no RMS power calculation that was useful. I ran into problems when
looking at tube curves and trying to calculate power levels. Nothing
came out quite right. Once I figured out the average power stuff then it
all fell into place. Same thing when trying to figure Peak envelope
power. The rms power figure will screw things up. "
Should a thread go too far "off topic" then I can see a point in
requesting it is dropped, or moved to private email. But this is very
relevant to RF amplifiers.
--
Dr. David Kirkby,
G8WRB
Please check out http://www.g8wrb.org/
of if you live in Essex http://www.southminster-branch-line.org.uk/
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