Hi Scott, I guess you couldn't see the dead pan
expression on my face as I typed. I was just being
tongue-in-cheek. Maxwell's just fine with me and I
agree with him 100%. In fact, so does the ARRL
Antenna Handbook! 73s
--- Scott Harwood <scotth@hsc.edu> wrote:
>
> Maxwell used to be a contributor to the ARRL Antenna
> Book and his book ?Reflections? sold through the
> ARRL. Now neither is true. As to the reason why,
> depends on who you want to believe; Maxwell or the
> ARRL!
>
> I prefer Maxwell.
>
> Scott K4VWK
>
> ---------- Original Message
> ----------------------------------
> From: Randy Russe3ll <lord_russell53@yahoo.com>
> Reply-To: Discussion of Ten-Tec Equipment
> <tentec@contesting.com>
> Date: Thu, 19 Jan 2006 10:49:27 -0800 (PST)
>
> >Sounds to me like Maxwell needs to go back and read
> >the ARRL Antenna Handbook.
> >
> >--- JOHN <ku3g@yahoo.com> wrote:
> >
> >> Thank You Scott finbally somebody has it correct.
> >> 73 john ku3g
> >> ps interestinmg subject
> >>
> >> Scott Harwood <scotth@hsc.edu> wrote:
> >>
> >> Hey guys:
> >>
> >> In his book, ?Reflections?, Maxwell states that
> all
> >> power fed into the transmission line (minus line
> >> loss) is absorbed by the load, regardless of the
> >> mismatch. Secondly, with open-wire tuned feed
> lines,
> >> we can ignore this mismatch at the junction of
> the
> >> feed line and the antenna, and all matching can
> be
> >> done at the transmitter itself. Put another way,
> if
> >> an antenna tuner can properly match the impedance
> of
> >> the input of the feed line, using open wire line
> we
> >> can transfer just about all power to the antenna.
> >>
> >> Thus, the case for open wire line and a tuner.
> >>
> >> Scott K4VWK
> >>
> >> ---------- Original Message
> >> ----------------------------------
> >> From: Randy Russe3ll
> >> Reply-To: Discussion of Ten-Tec Equipment
> >> Date: Wed, 18 Jan 2006 18:57:09 -0800 (PST)
> >>
> >> >Even if you have a finely tuned resonant dipole,
> >> and
> >> >it is actually 50 ohms at your feedpoint
> heighth,
> >> >you're losing more db in 100 feet of coax than I
> am
> >> on
> >> >a mismatched 4:1 swr. If you put your loading
> coils
> >> >on to "fool the transmitter" your using even
> more.
> >> If
> >> >you try to use your coax on any kind of
> mismatch,
> >> your
> >> >losses skyrocket. This includes feeding a 35 ohm
> or
> >> >say 80 ohm feedpoint with 50 ohm coax. Those are
> >> both
> >> >Z's attained on dipoles between 20 feet in the
> air
> >> and
> >> >a full wave high. The purpose of coax is
> >> convienence
> >> >swapped for performance. A link coupled tuner is
> >> more
> >> >of an Antenna impedance transformer. You've
> already
> >> >got a few of those in your rig anyway. I didn't
> see
> >> >anything supporting your theory about
> transmission
> >> >lines in the ARRL Antenna book. In fact, if you
> go
> >> >back and read it, you will understand what I'm
> >> saying
> >> >about losses in coax, and the reasons for the
> >> >superiority of balanced feedlines. In a multi
> band
> >> >system, it's an absolute must. Oh, and resonance
> is
> >> >NOT a requirement for radiation efficiency. 73s
> >> >--- Roger Borowski wrote:
> >> >
> >> >> After more than 45 years of continual hamming
> on
> >> all
> >> >> bands and modes, I can
> >> >> honestly say that I never have used an antenna
> >> tuner
> >> >> and never found any
> >> >> system that will outperform a resonant antenna
> >> fed
> >> >> with coaxial cable, which
> >> >> I've always used since the early 60's. If the
> >> >> antenna isn't resonant on the
> >> >> desired frequency of operation, many people
> think
> >> an
> >> >> antenna tuner is the
> >> >> fix. While an antenna tuner will allow you to
> use
> >> >> most anything metallic as
> >> >> a radiator of RF, the most efficient power
> >> transfer
> >> >> is to a 50 ohm resonant
> >> >> load via 50 ohm coaxial feedline. In all cases
> >> where
> >> >> an antenna tuner is
> >> >> used with a coaxial fed antenna, all it does
> is
> >> >> further complicate a system
> >> >> with an added piece of equipment that only
> fools
> >> the
> >> >> transmitter into seeing
> >> >> the match it is looking for, while creating
> >> losses
> >> >> in itself and further
> >> >> losses in the coaxial feedline due to the
> >> mismatch
> >> >> that still remains
> >> >> between the antenna tuner and the antenna.
> >> >> Fortunately I've never been
> >> >> forced to use anything other than resonant
> >> antennas
> >> >> fed with good quality 50
> >> >> ohm coaxial cable. If you're bound and
> determined
> >> to
> >> >> use open wire feeders
> >> >> to one of the many non-resonant antenna
> designs
> >> of
> >> >> yesteryear, that would
> >> >> require an antenna tuner. Why anyone who
> >> understands
> >> >> antennas would want to
> >> >> do that 50-60 years after coaxial cable became
> >> >> common place is beyond my
> >> >> comprehension. It's an easy chore to adjust
> >> antenna
> >> >> lengths for resonance
> >> >> and where available space doesn't permit, it's
> >> also
> >> >> easy to use loading
> >> >> coils or linear loading configurations on the
> >> >> antenna. If you haven't a clue
> >> >> as to what I'm saying, pick up a book on
> >> antennas,
> >> >> such as the ARRL Antenna
> >> >> Book and read the entire section on the theory
> of
> >> >> antennas. As a Ham, you
> >> >> really need to know this. An antenna tuner is
> a
> >> band
> >> >> aid approach that
> >> >> allows one to use an inefficient antenna,
> >> whatever
> >> >> it may actually be, with
> >> >> some degree of success. You see 1:1 SWR on the
> >> tuner
> >> >> meter and you and your
> >> >> rig are happy, but in actuality, put another
> SWR
> >> >> meter after the antenna
> >> >> tuner and you'll see the real mismatch, why
> you
> >> are
> >> >> generating RFI, and
> >> >> experiencing far less performance, both
> >> transmitting
> >> >> and receiving, than you
> >> >> could be.
> >> >> 73, -=Rog-K9RB=-
> >> >> FCC First Class Commercial License first
> attained
> >> in
> >> >> 1967, Ham Radio license
> >> >> first attained 1961.
> >> >> A-1 Operator Club, ARRL Life Member, DXCC #1
>
=== message truncated ===
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