[Boatanchors] Was 813 grid to filament... - now antenna tuners

[Bill Cromwell]

Well...

...there is another term that must expire before I do.

Crossing it off my list now.

73,

Bill  KU8H



On 10/03/2015 01:41 PM, D C _Mac_ Macdonald wrote:
> *I subscribe to a Merriam-Webster list entitled "Word of the Day."  A 
> very recent posting debunked the commonly held idea that "doozy" and 
> its various other spellings somehow relates to the Duesenberg 
> automobile.  The etymology of the word apparently relates way back to 
> the word "daisy" (and others) in the sense of meaning a superlative 
> example of a specific grouping.  This root is apparently at least a 
> full century before the invention of the automobile! *
> *
> * * * * * * * * * * *
> * 73 - Mac, K2GKK/5 *
> * (Since 30 Nov 53) *
> * k2gkk hotmail com *
> * Oklahoma City, OK *
> * USAF & FAA (Ret.) *
> * * * * * * * * * * *
>
>
> *
> *> To: boatanchors at mailman.qth.net
> > From: wrcromwell at gmail.com
> > Date: Sat, 3 Oct 2015 13:11:31 -0400
> > Subject: Re: [Boatanchors] Was 813 grid to filament... - now antenna 
> tuners
> >
> > Thank you Gary,
> >
> > In spite of occasional curmudgeonly behavior here most of the list
> > members are intelligent enough to figure out most typos (there are some
> > real Duesies once in a while). I didn't notice any typos but I'm not
> > necessarily the sharpest tool in the shed. Besides that - we are not
> > draughting legislation here so typos are often inconsequential.
> >
> > I have two Johnson Matchboxes and some L networks with which I tune the
> > transmitter end of my antenna system. I definitely tune something so I
> > often call it an antenna tuner because my antenna system starts 
> where my
> > transmitter (or receiver) leaves off.
> >
> > *Real Duesie* comes to us from having a fabulous automobile named a
> > Duesenberg; a real duesie as opposed to a cheap flivver. Some typos are
> > unintelligible - real duesies
> >
> > 73,
> >
> > Bill KU8H*
> >
> > On 10/03/2015 09:19 AM, Gary Peterson wrote:
> > > ”You are correct. Actually what they are are (adjustable) 
> impedance transformers...
> > > Eugene W2HX”
> > >
> > >> N0DGNsaid:
> > >> They are matchboxes! the impedance of the antenna hasn't changed 
> one little bit!
> > >> All you do is make the transmitter/transceiver happy. The feed 
> line and the antenna don't change one iota.
> > > It is not incorrect to call the matching device in your ham shack 
> an “antenna tuner,” rather than a matchbox, a transmatch or an 
> impedance transformer.
> > >
> > > Walter Maxwell, W2DU (SK) wrote on this subject in a series of 
> articles in QST, called “Another Look at Reflections.” He also 
> published at least three editions of a book called “Reflections.”
> > >
> > > Mr. Maxwell was no dummy when it came to this subject. He was an 
> antenna design engineer, employed by RCA, and several of his designs 
> ended up in Earth orbit and on the Moon.
> > >
> > > Maxwell pointed out the importance of the conjugate matching 
> theorem, which states that if a conjugate match is achieved at one 
> point in a system, then a conjugate match exists in every other point 
> in the same system.
> > >
> > > A conjugate match is defined (paraphrasing on my part) as having 
> equal resistances and equal reactances (if there is any), of opposite 
> sign, as one looks in both directions from a point in a system. An 
> example would be at the feedpoint of a dipole where, at a given 
> frequency, the resistance of the dipole is 82 ohms and the reactance 
> is +j 35 ohms (inductive). Looking back into the feedline, the 
> resistance would be 82 ohms and the reactance would be –j 35 ohms 
> (capacitive).
> > >
> > > Assuming a low loss feedline, this means that if you achieve a 
> match, in the ham shack, with your L, tee, pi or whatever network 
> between your transmitter and feedline input, there now exists a 
> conjugate match between the end of the feedline and the antenna. One 
> of his articles was entitled “My Transmatch Tunes My Antenna,” as I 
> recall.
> > >
> > > Mr. Maxwell is in good company. Several of my BSEE and MSEE 
> friends are in complete agreement with him.
> > >
> > > There is no reason to jump on anyone who refers to the matching 
> unit in their shack as an “antenna tuner.” It is just one of several 
> correct terms for the device.
> > >
> > > Gary, KØCX
> > >
> > > PS - I just got out of bed...so I hope there are no typos in above...