On Mar 27, 2005, at 4:33 AM, David Kirkby wrote:
> 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
>> ...
>
> 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' ...
...
> 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.
chortle
>
> 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.
As I see it, a more meaningful measurement is what effect an amplifier
has on S-meter readings. Experience has taught me that a 20db change
in PEP does not always produce 20db more or less signal at the
receiver.
>
> 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.
I have conducted many tests on 40m during daylight hours where I
increased PEP by 40%, and, thanks to QSB, so far no one has been able
to consistently detect the change on a S-meter at the Rx end.
>
> 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. ...
... ... ...
Indeed, David, indeed. I see a connection with Freudian psychohistory
and also what Andy Warhol said about 15-minutes.
Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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