I agree on the inaccuracies in some of the ARRL publications. The same
errors are reprinted year after year without apparently anyone checking
the subject matter. I am the first to admit that most, if not all of
the errors, are due to mistakes in the typesetting, after all the
humble printer is not a degreed engineer, but I thought the "galleys"
are supposed to be sent to the original author for approval.
I came across a classic mistake today in the ARRL Microwave
Experimenters Handbook in the section dealing with Cavity amplifier
design. As I was wishing to refresh my memeory, at the same time as
building a new 23cm PA, I took the example which was skimpily worked
out and double checked the calcs. Just as well as I would been several
10's of $$ out of pocket with scrap metal because of a simple error in
the calcs. It cannot even be called a typo as the correct answer to one
part was 37,7 ohms and 3 lines further on it somehow became 34,94 ohms?
I may have an old edition but I am not sufficiently wealthy to buy
every new edition when it comes out.
John ZS5JF
----------
> From: john merryman <andy_m_99@yahoo.com>
> To: amps@contesting.com
> Subject: Re: [AMPS] big or small amps, we're all hams
To: <amps@contesting.com>
> Date: 26 January 1999 04:03
>
>
>
> Yes i agree totally, there are some individuals who dont want to
> educate people, but who just want to bottle up information, either
for
> commercial gain or just have a poor attitude, and some people who
just
> love making fun of people in front of others. This is a recent
> phenomenon, since in days gone past people were willing to share
> knowledge.
>
> Equally sad is the quality of printed information, i must admit now
> that i go through bookshops and hamfests looking for all the old
radio
> engineering and electronic book, because they explain things in
simple
> clear english. The maths is also very well illustrated. I have
learned
> more from these books than all issues of the Arrl Handbook put
together.
>
> The ARRL and others complain about black box operators all the time,
> yet they are supposed to be educating us and trying to improve our
> knowledge, yet they fail at this. Look at the Handbook, besides all
> the geniuses on this board, has anyone actually looked at the section
> on High Voltage Power supply design, its not very good. Its
> application of maths, formulas and design principles is very poor and
> has many errors. If you want to build a canned project power supply
> its great, but if you want to understand how to design and calculate
> things and go your own way, you will struggle if you are a newcomer.
> There are many other areas like this in the Handbook. CARL THEIR IS A
> CONTRACT JOB OPPORTUNITY, STRAIGHTEN THESE ARRL MORONS OUT, and show
> them how its done.
>
> Yet a Guy Like RICHARD MEASURES, can on his web page teach you more
in
> 50 pages about amps and high voltage power supplies than it would
take
> 10 years to accumalate waiting for articles in QST QEX etc, or the
> latest ISSUE of the Handbook, KEEP UP THE GOOD WORK RICH.
>
> Well some could learn from the honest and true Ham spirit of Rich
> Measures, i wish their was a 100 more individuals like him, who help
> share and educate and raise the standards of us all. Because many
> would like to reduce us to morons, that use articles and kits without
> understanding what they are doing. We will be back in the dark ages
> going Hail The Great God Carl!
>
> nuff said
>
>
>
> ---John Fielding <johnf@futurenet.co.za> wrote:
> >
> >
> > Thanks John for bringing a voice of "medium road" to the
discussion.
> I
> > have learnt a lot from several professional rf engineers who are
not
> > hams but understand high power amplifiers and are willing to pass
on
> > some of their knowledge. Often the questions must sound kind of
> > stupid, but if you don't ask you won't learn!!
> >
> > Incidentally the term "expert" was explained to me many years ago.
> >
> > An Ex is a "has-been" and a "Spurt" is a drip under pressure - Hi.
> >
> > John ZS5JF
> >
> > ----------
> > > From: John T. M. Lyles <jtml@lanl.gov>
> > > To: amps@contesting.com
> > > Subject: [AMPS] big or small amps, we're all hams
To: <amps@contesting.com>
> > > Date: 25 January 1999 10:07
> > >
> > >
> > > I realize that the heat may have passed, but I just wanted to
> comment
> > on
> > > one sentence that I read this morning:
> > >
> > > >>And then claiming that those who help the poor guy are just
> > building
> > > >>there egos is just absolute rubbish. Many thanks to guys like
> Rich
> > > >>Measures and John Lyles for doing some good old fashioned
> elmering.
> > > >
> > > >
> > > >Yeah sure, how many need 100KW Elmers that have zero revelence
to
> > any ham
> > > >reality? Interesting reading but of no practical use at 1500W.
> > >
> > > The theory and practice of RF power amplifiers are identical,
> whether
> > it's
> > > 100 watts or 100 Megawatts. Pi networks, tubes, HV power
supplies.
> It
> > all
> > > scales up or down. Ohms law always seems to work. Maybe corona
> creeps
> > in,
> > > but other than that.....
> > >
> > > I don't particularly believe that it is irrelevent, or I would
not
> > have
> > > even mentioned what I build for my own career thing. I could
just
> > sit here
> > > talking about my modified SB220 (it does work, and has the same
mods
> > that
> > > most hams chat about here) but I thought something more
interesting
> > to most
> > > amplifier builders would be other units, that use the EXACT same
> > > prinicipals as the 1500 watters. In 1978 I built/modified an 829B
> > amplifier
> > > on two meters. Yuk! But I learned from that old piece. Most of
the
> > advice
> > > that I read from a number of very knowledgeble RF experimenters
> here,
> > I
> > > agree with. Which is exactly why I don't like to waste bandwidth
on
> > the
> > > Internet complaining, or shooting down other peoples circuits.
> When a
> > less
> > > experienced amplifier builder asks a question, which may be
common
> > > knowledge to 'experts', hams take the time to reply, and the
> > requester gets
> > > a variety of answers, to sort through. Usually, if one reads
them,
> > there is
> > > a common middle ground answer than can be distilled. Funny, I
never
> > even
> > > looked to see ham calls, or what the power level is. I do not try
> and
> > > police what someone will use RF power for, as a number of people
> here
> > use
> > > RF in their work. I have met a lot of people here, who do bigger
RF
> > systems
> > > than 1500 Watts, and never mention it here. This appears to be
the
> > only
> > > forum I have seen that covers all RF power amplification.
> > >
> > > The same tube/transistor manufacters apply. The same passive RF
> > components
> > > - ceramic caps, doorknobs, micas, vacuum variables, in bigger or
> > smaller
> > > PAs. I have learned a lot reading the AMPS reflector, and applied
> > some of
> > > the new knowledge to my own designs. I assume that others do the
> > same. I do
> > > not sell my designs for $$ here, nor to I recommend that all read
> > every
> > > word that I say and believe it.
> > >
> > > I am an advanced class ham, since 1971, a youngster compared to
some
> > - but
> > > I am middle aged! I would have gotten extra class except for the
20
> > WPM.
> > > Maybe it will finally happen. Ham radio got me into RF, along
with
> > working
> > > in a small town radio station back then. I am happy to have
gotten
> to
> > do
> > > the things that i liked, and been paid for it. Everyone can do
this
> > in
> > > whatever field they wish, if they really try. OK, enough said,
i'm
> > sounding
> > > like one of those self-help talk shows, but I hate seeing people
> > bashing
> > > themselves and others over their opinions.
> > >
> > > 73
> > > John
> > > K5PRO
> > > (former WN4PRO, WB4PRO)
> > >
> > >
> > >
> > >
> > >
> > > --
> > > FAQ on WWW: http://www.contesting.com/ampfaq.html
> > > Submissions: amps@contesting.com
> > > Administrative requests: amps-REQUEST@contesting.com
> > > Problems: owner-amps@contesting.com
> > > Search:
http://www.contesting.com/km9p/search.htm
> >
> > --
> > FAQ on WWW: http://www.contesting.com/ampfaq.html
> > Submissions: amps@contesting.com
> > Administrative requests: amps-REQUEST@contesting.com
> > Problems: owner-amps@contesting.com
> > Search: http://www.contesting.com/km9p/search.htm
> >
> >
>
>
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>
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> FAQ on WWW: http://www.contesting.com/ampfaq.html
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--
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Search: http://www.contesting.com/km9p/search.htm
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