I sure didn't, Randy. FB on the ARRL Handbook. I enjoy it also. I can't
remember precisely what precipitated the spat between ARRL and Maxwell. Seems
to me it had something to do with UHF antenna design and nothing about feedline
stuff.
Anyhow, thanks for the clarification.
73,
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 13:25:12 -0800 (PST)
>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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