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Re: [Amps] Measuring RF Power

To: <amps@contesting.com>, "Alek Petkovic" <vk6apk@eon.net.au>,"Bill Fuqua" <wlfuqu00@uky.edu>
Subject: Re: [Amps] Measuring RF Power
From: "Dr. William J. Schmidt, II" <bill@wjschmidt.com>
Reply-to: "Dr. William J. Schmidt, II" <bill@wjschmidt.com>
Date: Mon, 28 Mar 2005 19:22:58 -0600
List-post: <mailto:amps@contesting.com>
Agree, but only if we do the same for: 1) parasitic oscillation suppression, 
2) the proper way of connecting 220 VAC to an amp, 3) how to calculate L, C, 
make coils, etc., 4) what does grounded grid mean,  5) how come my amp 
explodes....  well, you get the picture.

Sincerely,

Dr. William J. Schmidt, II  K9HZ
Trustee of the North American QRO - Central Division Club - K9ZC

Email: bill@wjschmidt.com
WebPage: www.wjschmidt.com

"If computers get too powerful, we can organize them into a committee; that 
will do them in."  -- Bradley's Bromide


----- Original Message ----- 
From: "Bill Fuqua" <wlfuqu00@uky.edu>
To: "Dr. William J. Schmidt, II" <bill@wjschmidt.com>; 
<amps@contesting.com>; "Alek Petkovic" <vk6apk@eon.net.au>
Sent: Monday, March 28, 2005 9:29 AM
Subject: Re: [Amps] Measuring RF Power


>I think if we just package all the emails about this subject and keep the 
>"package" attachment  handy for the next time this  comes up just send it 
>to the person with the question instead of going thru this again and again 
>over the years. I know we have gone thru this exercise twice maybe three 
>times already.
>
> 73
> Bill wa4lav
>
>
> At 08:39 AM 3/28/2005 -0600, Dr. William J. Schmidt, II wrote:
>>I agree....  Lots of good discussion.
>>
>>Sincerely,
>>
>>Dr. William J. Schmidt, II  K9HZ
>>Trustee of the North American QRO - Central Division Club - K9ZC
>>
>>Email: bill@wjschmidt.com
>>WebPage: www.wjschmidt.com
>>
>>"If computers get too powerful, we can organize them into a committee; 
>>that
>>will do them in."  -- Bradley's Bromide
>>
>>
>>----- Original Message -----
>>From: "Alek Petkovic" <vk6apk@eon.net.au>
>>To: <amps@contesting.com>
>>Sent: Monday, March 28, 2005 6:54 AM
>>Subject: Re: [Amps] Measuring RF Power
>>
>>
>> > It is surely the best thread we have seen on this reflector in a long 
>> > long
>> > time. Very comprehensive, informative and lots of fun to follow.
>> >
>> > Thanks to all,
>> > Alek. VK6APK
>> >
>> > At 08:33 PM 27/03/2005, 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
>> >> >_______________________________________________
>> >> >Amps mailing list
>> >> >Amps@contesting.com
>> >> >http://lists.contesting.com/mailman/listinfo/amps
>> >> >
>> >> >
>> >> >
>> >> >
>> >>
>> >>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/
>> >>
>> >>
>> >>
>> >>_______________________________________________
>> >>Amps mailing list
>> >>Amps@contesting.com
>> >>http://lists.contesting.com/mailman/listinfo/amps
>> >
>> > http://www.qrz.com/vk6apk
>> > http://profiles.yahoo.com/vk6apk
>> >
>> > _______________________________________________
>> > Amps mailing list
>> > Amps@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/amps
>> >
>>
>>
>>_______________________________________________
>>Amps mailing list
>>Amps@contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>
> 


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