Circular polarization... does it have to be synchronous??
 

Peter O. Brackett wrote:
Jerry:

[snip]
I dont think a rotating dipole with DC on it will generats a field
that propogates. Your post reads as though you dont think the
rotating DC dipole will producing a propogating Far Field. I read
other posts that seem to indicate that others assume the DC spinning
dipole will generate a propogating "far field". It is sad that I am so
lazy that I cannot express myself using Cross Products. But, I submit
that it takes more than rotating a dipole to produce a propogating far
field.

I dont understand where the "Cross H" is generated by a rotating DC
dipole, as required for propogation.

I dont understand why it requires more power to rotate a DC dipole
with increased voltage on it, as required to account for the increased
power.

Jerry KD6JDJ
[snip]

What is required to generate electromagnetic radiation is any movement of
electric charge such that there exists a rate of change of the
positional acceleration
of electric charge. This can be derived from first principles from the
Maxwell/Heaviside
equations. There is a section in the volume of Feynman's Lectures on
Physics that
discusses this, and I believe that the previous editor of QEX magazine
wrote an
article outlining a derivation of this a year or so ago.

In physics and dynamics the rate of change of acceleration is termed
"jerk".

In terms of simple differential calculus, there is position ("x"), there
is velocity
("v = dx/dt") the rate of change of position, there is acceleration ("a
= dv/dt")
the rate of change of velocity, and there is jerk ("j = da/dt") the rate of
change of acceleration. Expressing it in these terms, it can be said
that it
it can be shown from the Maxwell/Heaviside partial differential equations
that govern all of electromagnetics, that radiation occurs when ever
electric
charge is "jerked". i.e. whenever the rate of acceleration of charges
changes
either up or down.

Now in sinusoidal realms, where all the signals are assumed to be of sine
wave shapes, we know from simple differential calculus that differentiating
sine waves results in more sine waves. In other words a sine wave current
comprises electric charges changing position according to a sine waveform,
and so perforce is the velocity, acceleration and jerk of those charges.
Hence
whenever electric current motion follows a sine-like wave there will be
radiation caused by the sinusoidal 'jerk'.

Now there are more forms of acceleration than just sine wave motion.

For example when things have angular motion, there is centrifugal
acceleration, and when things move on a rotating frame there
is coriolis acceleration, etc... and so in general whenever electric
charges are put in motion, the exception being simple motions where
the third derivative of motion is zero, there will be radiation caused
by that motion.

All of the above details are well known to most physicists who study
electromagnetics, from first principles (Maxwell/Heaviside), these 'facts'
are less well known to most (modern) electrical Engineers.

Consequently I find it easy to believe that the mechanical motion of
any body with electric charge on it, be that charge DC or AC is highly
likely to radiate electromagnetic waves.

All of this is difficult, actually impossible, to simulate with NEC codes
like Roy's EZNEC since those analysis codes all assume a simple
steady state fixed sinusoidal regime for the framework in which
the Maxwell/Heaviside equations are solved. NEC does not
provide for the simulation of antennas in motion! And so...

It is beyond the capability of NEC in general or EZNEC in
particular to generate field patterns for rotating dipoles!

Othewise someone (Cecil maybe?) would already have run
a simultation on EZNEC to refute my claims to being able
to generate circular polarization by mechanical rotation.

In other posts in these threads on CP I have asked if anyone
knows of any simulation software (generally would be in the
category called "multi-physics packages" that can adequately
simulate/calculate the fields for rapidly rotating dipoles driven
by sinewaves at arbitrary frequencies. If so I'd like to know.
And I'd like to simulate some of my "theories" just to prove
my assertions.

Actually it may be easier to emulate (i.e. prototype) such
a spinning dipole. In fact one does not have to mechanically
spin a dipole to do this. One can generate the same fields
as a spinning dipole by applying the "right" signals to two
orthogonal linear dipoles. i.e. a synthetic or phased array
beam former, that emits circularly polarized beams of
arbitrary rotation velocity.

Phased arrays can be elctronically scanned or rotated,
this is in fact how most modern STAP radars work, e.g.
Aegis, etc... and so one can electronically rotate emitted
waves in the same way. It's not cheap, but it can be done.

My curiosity is along the lines of if you could find a cheap
way of rapidly spinning an emitting dipole, what new
applications might arise from that.

As far as I can determine, no one has yet done the experiments
that I have been discussing here in these threads.

And so my suggestions/theories are met with comments
like, "It's never been done before, why would you want to do it,
etc, etc... ?

Why do I ask such questions?

Just curious or perhaps I'm just plain stupid!

But no one has yet been able to categorically refute my assertion.

Whenever charge is jerked there is radiation!

Food for thought.

-- Pete K1PO
-- Indialantic By-the-Sea, FL

Do you have any hobbies?

Circular polarization... does it have to be synchronous??
 

Dave:

[snip]
Do you have any hobbies?
[snip]

Technical hobbies, or social hobbies?

Other than kibitzing on r.r.a.a?

Would you believe that I'm a salsa dancing champion? Actually my wife Kathy
(who is a dance genius) and I do a lot of dancing which might be described
as a "hobby" of sorts.

Let me tell you about one of our recent dance escapades.

About three weeks ago my wife and I were in Paris, France, returning from
three weeks in Italy where, among other things, we hiked to the top of
Vesuvius. But that's another story!

All this to say that we stopped over for a night in Paris on our way back to
Indialantic from Naples. We took the opportunity to take in dinner and a
show at the celebrated Moulin Rouge near Pigalle in Paris.

Ouch! That was an expensive evening! It didn't look too bad in Euros, but
when the bill showed up on my Visa statement in US$ it was heart stopping!

Front row seats at the Moulin Rouge, right up against that venerable125 year
old stage, and the multi-course meal with a magnum of champagne was great
and as you will note from the rest of my "story" it turned out to be a
memorable evening!

Kathy and I took the train from CDG airport into the Gare du Nord, and then
we took the Paris Metro over to the Pigalle station leaving time to get lost
at least three times before we got there. Pigalle as you know is in the
center of the "red light district" of Paris. The Moulin Rouge is in the
middle of that district on Monmatre, the dandy's, Princes and Princesses do
not walk along Pigalle to get to the Moulin Rouge like Kathy and I did,
rather they arrive right in front of the door in long black Mercedes
limousines.

Well... at the Moulin Rouge they serve a first class dinner before the show
if you elect to take the dinner and show rather than just the show.

During dinner, a small elegant music ensemble is fronted by a talented duet
of singers, who are sort of the Parisian equivalent of
Edye Gorme and Steve Lawrence, except they sing in French, such songs as
"Chanson d'Amour", etc. as enteratinment for the diners.

During dinner that part of the main stage that later becomes elevated during
the main show is kept at ground level so that people can dance if they wish,
during dinner, and before the main show.

The Moulin Rouge was packed the night we were there and, as usual whenever
there are lots of "observers", there were not many dancers on the floor!
Only a couple of pairs, who had consumed all of their champagne by that time
got up to dance staggered through a few 'slow dance' steps, and so the floor
of the Moulin Rouge looked downright barren.

My wife Kathy suggested that WE get up and dance. As a dance instructor,
you can well imagine that Kathy is not shy about that kind of thing. My
athy always likes
to be the first one out on the dance floor.

Well the small ensemble and the two singers got round to a number with a
certain beat (NC2S) that my wife and
I like and so Kathy suggested that we get up on the Moulin Rouge dance
floor in front of the whole audience that night
and do the Night Club Two Step.

Now for those of you who don't know, the NC2S is a modern dance that was
"invented" by and American,
Buddy Schwimmer of Costa Mesa, CA a few years ago. NC2S is a very elegant
dance done to slower music and is very elegant and quite
unique.

Aside: NC2S is known in the USA but likely not well known in Europe. In case
you are not a dancer, you should know that Buddy Schwimmer
happens to be the father of Benji Schwimmer who won the "So You Think You
Can Dance" show two years ago, and he is also the father of Lacey
Schwimmer who was partnered with Lance Bass on the "Dancing with the Stars"
show this past fall. Lacey and Lance
came in second on the show this year, after that graceful "Brooke Burke" and
her partner Derek Hough.

And so... "there we were", my wife Kathy and I dancing the elegant Night
Club Two Step all alone on the dance floor of the Moulin
Rouge in Paris, in front of an International audience of several hundred
people.

Well... we were surprised! As we danced together to that beautiful slow and
sexy music, all of the dinner "chatter" stopped and all eyes
in that famous 125 year old theatre, were on us as I showcased Kathy's
wonderful dance skills (as the dance partner/leader).

The highlight came as the music ended and we walked back to our dinner
table.

The audience at the Moulin Rouge favored us with a standing ovation!

Apparently they had never seen the Night Club Two Step before!

Unfortunately no one recorded the happenings at the Moulin Rouge that night,
but... for those of you who might be interested to see what the NC2S looks
like
as it is danced, you see an example on You Tube, just click on...

http://www.youtube.com/watch?v=VoyxrEbZpSw

BTW... the Moulin Rouge show after dinner and dancing was spectacular and
well worth the $$$$$.

I suppose that if it were not a 125 year old tradition in Paris that the
Moulin Rouge show mighty be described by Americans as a "high end" Las Vegas
show,
except that... Las Vegas, NV was not even in existence when the Moulin Rouge
started its run 125 years ago!

I'd say that one should really describe Las Vegas shows as pale imitations
of the Moulin Rouge show! [smile]

Guys who are reading this will be pleased to know that not only is the whole
show spectacular, but the show girls at Moulin Rouge are spectacular as
well.

All this to say, Dave.... yes I do have hobbies!

And... I am often "asked to dance"...

BTW.... I highly recommed dance to any man/boy who wants to be closely
asociated with women!

Dave, I'd challenge you to name a hobby for a man that is as exciting as a
hobby where the man gets to hold attractive girls in his arms and run his
hands all over thier bodies for 3-5 minutes at a time and the girls thank
him when it's over and asks him if they could do it again soon?

Ciao!

-- Pete K1PO
-- Indialantic By-the-Sea, FL

Circular polarization... does it have to be synchronous??
 

On Sat, 13 Dec 2008 09:41:46 -0500, "Peter O. Brackett"
wrote:

None of the guru's lurking around this particular newsgroup (r.r.a.a) will
deny that whenever electrical charge is "jerked" that photons are emitted.

At the risk of being so identified with that villified group, I will
deny that statement (for what it is worth).

And... none of the gurus hanging hereabouts will deny that photons can have
'spin'.

That is a fairly short list of what is "not" denied. Why don't you go
further like Gurus refuse to deny:
1. They hate their parents;
2. They stopped beating their wives;
3. The earth is perfectly round;
4. Gussian arrays are the perfect metaphor for radiation;
....
n. and on and on and -heh heh- on.

73's
Richard Clark, KB7QHC

Circular polarization... does it have to be synchronous??
 

Richard:

[snip]
"Richard Clark" wrote in message
...
On Sat, 13 Dec 2008 09:41:46 -0500, "Peter O. Brackett"
wrote:

None of the guru's lurking around this particular newsgroup (r.r.a.a) will
deny that whenever electrical charge is "jerked" that photons are emitted.

At the risk of being so identified with that villified group, I will
deny that statement (for what it is worth).
[snip]

Your denial is not worth to much simply because, as The Bard had one of his
thespian protagonists quote,
"methinks he doth protest too much".

And, so... well, I am afraid to admit that... I don't really know which of
the honored denziens of this
group (r.r.a.a) are the select members of the secret clique of lurkers known
as "The Gurus".

It seems from what you have written above that you deny being one of The
Gurus.

I believe it was Groucho Marx who said, "I wouldn't want to be a member of
any club that would accept
me as a member", and so...

Me?

Hmmm... I not only deny membership in The Gurus, but I actually know that I
am not a member.

Now, if my recollection is correct, Reg Edwards may have known the names on
that secretive list of gurus, but
since Reg has now passed to his reward and, although we have evidence of
Reg's own electromagnetic expertise
in the form of the many programs and web site information he graciously left
for us gratis, there is no evidence
that Reg ever belonged to The Gurus. In fact, I recall Reg indirectly
denying his own membership on many
occasions by referring difficult and sometimes rhetorical questions to "The
Gurus", often answering those
questions himself after much newsgroup discussion.

Apparently Art Unwin has definite knowledge of who The Gurus are, since he
often challenges and castigates
them at the same time. Unfortunately Art would condemn the poor IEEE
because of corrupt behavior, and
so I am not sure that Art is really connected in the electromagnetic world.

All this musing to note that... USENET is a great tool for scientific
discussion, that adheres to the most basic
tennets of "The Scientific Method".

Why, anyone... from freely identified persons, to anonymous posters, may
make whatever assertions and pose
whatever theories they care to, and everyone knows that eventually the truth
will be revealed as those assertions
are examined in the brilliant light of the scientific cross examination that
occurs in these r.r.a.a threads!

Hey! Where's Art when you need him? Art... I've created your opening, now
its your turn...

It's saturday night and I gotta go dancing, the girls are waiting... :-)

-- Pete K1PO
-- Indialantic By-the-Sea, FL
care to and

Circular polarization... does it have to be synchronous??
 

On Sat, 13 Dec 2008 18:21:10 -0500, "Peter O. Brackett"
wrote:

None of the guru's lurking around this particular newsgroup (r.r.a.a) will
deny that whenever electrical charge is "jerked" that photons are emitted.

At the risk of being so identified with that villified group, I will
deny that statement (for what it is worth).
Your denial is not worth to much simply because, as The Bard had one of his
thespian protagonists quote,
"methinks he doth protest too much".

I didn't think the question had any legs either. D.O.A.

Apparently Art Unwin has definite knowledge of who The Gurus are, since he
often challenges and castigates them at the same time.

He is like Septimus who awaits the death of his six brothers before
ascending to the crown.

Art... I've created your opening, now its your turn...

Stand back then, because you'll find him spitting at you in the chance
of catching me in the backwash.

73's
Richard Clark, KB7QHC

Circular polarization... does it have to be synchronous??
 

On Dec 13, 5:21*pm, "Peter O. Brackett"
wrote:
Richard:

[snip]"Richard Clark" wrote in message

... On Sat, 13 Dec 2008 09:41:46 -0500, "Peter O. Brackett"
wrote:

None of the guru's lurking around this particular newsgroup (r.r.a.a) will
deny that whenever electrical charge is "jerked" that photons are emitted.

At the risk of being so identified with that villified group, I will
deny that statement (for what it is worth).

[snip]

Your denial is not worth to much simply because, as The Bard had one of *his
thespian protagonists quote,
"methinks he doth protest too much".

And, so... well, I am afraid to admit that... I don't really know which of
the honored denziens of this
group (r.r.a.a) are the select members of the secret clique of lurkers known
as "The Gurus".

It seems from what you have written above that you deny being one of The
Gurus.

I believe it was Groucho Marx who said, "I wouldn't want to be a member of
any club that would accept
me as a member", and so...

Me?

Hmmm... I not only deny membership in The Gurus, but I actually know that I
am not a member.

Now, if my recollection is correct, Reg Edwards may have known the names on
that secretive list of gurus, but
since Reg has now passed to his reward and, although we have evidence of
Reg's own electromagnetic expertise
in the form of the many programs and web site information he graciously left
for us gratis, there is no evidence
that Reg ever belonged to The Gurus. *In fact, I recall Reg indirectly
denying his own membership on many
occasions by referring difficult and sometimes rhetorical questions to "The
Gurus", often answering those
questions himself after much newsgroup discussion.

Apparently Art Unwin has definite knowledge of who The Gurus are, since he
often challenges and castigates
them at the same time. *Unfortunately Art would condemn the poor IEEE
because of corrupt behavior, and
so I am not sure that Art is really connected in the electromagnetic world.

All this musing to note that... USENET is a great tool for scientific
discussion, that adheres to the most basic
tennets of *"The Scientific Method".

Why, anyone... from freely identified persons, to anonymous posters, may
make whatever assertions and pose
whatever theories they care to, and everyone knows that eventually the truth
will be revealed as those assertions
are examined in the brilliant light of the scientific cross examination that
occurs in these r.r.a.a threads!

Hey! *Where's Art when you need him? *Art... I've created your opening, now
its your turn...

It's saturday night and I gotta go dancing, the girls are waiting... :-)

-- Pete K1PO
-- Indialantic By-the-Sea, FL
care to and

Peter, there are no gurus on this newsgroup period
When I extended the Gaussian law of statics by making it a dynamic
field
I proved beyond doubt that radiation was via particles and not waves.
David and others denied that you could even bring in the subject of
statics
when discussing radiation even tho it is known that the force between
particles
is part and parcel of Maxwells laws. I might add that many joined him
in this thinking
like lemings. Since that time all of this group have sunk lower and
lower with respect to radio.
All have demanded a definition of equilibrium no less so all are
lacking in science.
They have all denied that mathematically my extension of Gauss results
in the same mathematics
that were arrived at by Maxwell. When I point out that eddy current
( really a field) is the weak
force that Einstein was looking for as he was convinced that
radiation held the clue he was looking for.
Yup they howled at that one too. Ofcourse it was Maxwell who found out
that one of the existing laws by the masters
was not in equilibrium which he then corrected by adding the
displacement current which describes the
action of the eddy current field in lifting and applying spin to a
charged particle. Howls again from all
as this could not be found in any books. Ofcourse this operation in a
macro scale is used daily in scrap
yards for sorting out materials as well as non destructive testing but
again the howls rose again.
So I then told them that maxwell based computor programs account for
all the forces used in radiation
which they could find out for themselves with a optimizer program as
long as the input was not slanted towards a planar design so that it
may be discarded
But then they are self perceived gurus thus don't need to use a
computer as all is already known, ala their books that are more than
50 years old.
I then informed them that one naval base had tipped all their
verticles for better performance by incorporating the weak fork which
also can be confirmed using Maxwells laws. Now I am being considered
and idiot no less. So I then posed the question as to where the
current goes when reaching the top
of a fractional wave antenna and the answers I got was that a closed
circuit is not required for radiation. And this thinking goes on and
on but at no time
has anybody come forward to refute my analysis in anyway, mathematics,
computor programs or what ever.
This whole story reminds me of the Yagi invention that was dismissed
totally by the Japanese intelligensia but embrace by the rest of the
world such that the Japanese never used the Yagi design thru out the
length of the war which was their loss. Peter, all of the above has
been pointed out to this group of self perceived gurus over the past
few years but all has been denied as it is no where in the books to be
read.
When I joined this group more than a decade ago Roy W7EL said he was
going to expose all the old wives tales that floated around including
all the newly touted sciences that were being tossed around but his
silence has been defining while at the same time Snakespere has been
prancing around in his fishnet pants while talking in tongues. Ian is
still demon strating how to solder a connector on coax while the Naval
instructor Woods in Washington
is in total belief that the US navy is using tilted antennas for
superior performance. No Peter, there are no gurus on this newsgroup
as I have one time or another proved that they are nothing more than
talking heads beyond doubt.
As an aside Peter on another subject I have no bone to pick with the
professional societies only the Universities for giving away
information provided by tax payers money and thus was not theirs to
remove from publics eyes
Best regards
Art Unwin.......KB9MZ.......xg (uk)

Circular polarization... does it have to be synchronous??
 

Art Unwin wrote:

...
I proved beyond doubt that radiation was via particles and not waves.
...

Best regards
Art Unwin.......KB9MZ.......xg (uk)

Actually, that is false ... you could not prove such a thing, unless you
force us to disbelieve our own eyes! To proceed claiming such is only
to invite us to think you daft!

http://www.newscientist.com/article/...1_head_dn14172

The best you can now argue is that light is composed of a type(s) of
particle(s) which travels as a wave(s); And, still, it seems to possess
both qualities--i.e., behaving both as particles AND waves ... but then,
we already knew that.

Regards,
JS

Circular polarization... does it have to be synchronous??
 

On Dec 13, 9:38*pm, John Smith wrote:
Art Unwin wrote:

* ... I proved beyond doubt that radiation was via particles and not waves.

* ...

Best regards
Art Unwin.......KB9MZ.......xg (uk)

Actually, that is false ... you could not prove such a thing, unless you
force us to disbelieve our own eyes! *To proceed claiming such is only
to invite us to think you daft!

http://www.newscientist.com/article/...ts&nsref=news1....

The best you can now argue is that light is composed of a type(s) of
particle(s) which travels as a wave(s); *And, still, it seems to possess
both qualities--i.e., behaving both as particles AND waves ... but then,
we already knew that.

Regards,
JS

John I am confident about my analysis. Scientists have not been able
to explain
anything in radio that procedes at the or near the speed of light or
explain how communication is resolved.
I have provided an explanation that is duplicated in many ways every
day and vindicated by Maxwells equations.
Reviewing the URL you supplied. The photograph is not a simple proof
that it appears to be. Camera pictures are notorious
in fooling people into falible interpretatations. However you can
believe what you want. I would point out that I have melded many
things and aproaches
such that all mesh in a single conclusion None of these separate
aproaches have had any errors pointed out whether it be mathematics or
otherwise.
I am not a programmer so there is no way I could have injected such a
complicated scenario into all the programs now available. Nor could I
have invented the weak force that Einstein was convinced resided in
the analysis of radiation. On the other hand there are many
photographs available of the Lock Ness monster, alien space craft and
alabaster statues with tears coming from the eyes. By the way, compare
different aproaches of resolving radiation analysis and check which
form provides the minimum losses and you will find that planar
antennas just don't measure up versus antennas in equilibrium. On the
other hand if the field of an eddy current is not the weak force that
Einstein forcast or predicted then where and what is this force that
propels a wave, presumably without spin that knocks out what I have
suggested? At the same time does it fit exactgly the jigsaw pussle
that Maxwell left us with the puzzle turned over so the picture could
not be pre determined? And as a finale I see particles occilating
possibly in tandem form that gives the impression that the particles
arenot interconnected in string form but a series of interactions
between particles that operate in their own right als
H2O in molecular but unbound form as with mass
Best regards...... good effort but no cigar. I would aim for best
results at the computer programs or finding the true weak force, or
determining how a electrical wave travels with intelligence or the
center of all proove that the mathematics as applied to gaussian
boundary that is made dynamic under a time varying field DOES NOT
equate with the mathematical laws of Maxwell and last of all that the
term equilibrium has NO PLACE in the laws devised by the masters with
respect to the Universe. I left out the part that a radiater must be
straight as expoused by some pseudo experts in the radio field as well
as to how the addition that Maxwells made to his laws provide the
mathematics for the tilting action on a radiator for minimum lossand
the many other things I have pointed out
My very best regards and best wishes in any endeavor that you wish to
undertake in an effort to proove me in error. There will be some
talking in tongues by the group but I am absolutely positive there
will be no fresh revalations other than just words provided over the
years which have meant nothing
other than the intent to hurt. Goodnight
Art Unwin KB9MZ..........XG....(UK)

Circular polarization... does it have to be synchronous??
 

Art Unwin wrote:
On Dec 13, 9:38 pm, John Smith wrote:
Art Unwin wrote:

... I proved beyond doubt that radiation was via particles and not waves.

...

Best regards
Art Unwin.......KB9MZ.......xg (uk)
Actually, that is false ... you could not prove such a thing, unless you
force us to disbelieve our own eyes! To proceed claiming such is only
to invite us to think you daft!

http://www.newscientist.com/article/...ts&nsref=news1...

...
Reviewing the URL you supplied. The photograph is not a simple proof
that it appears to be. Camera pictures are notorious
in fooling people into falible interpretatations. However you can
believe what you want. I would point out that I have melded many
things and aproaches
...
Art Unwin KB9MZ..........XG....(UK)

Well, that is simple enough then. You are to have us disbelieve our own
eyes ... good enough, we have that cleared up.

Regards,
JS

Circular polarization... does it have to be synchronous??
 

On Dec 14, 3:50*am, John Smith wrote:
Art Unwin wrote:
On Dec 13, 9:38 pm, John Smith wrote:
Art Unwin wrote:

* ... I proved beyond doubt that radiation was via particles and not waves.

* ...

Best regards
Art Unwin.......KB9MZ.......xg (uk)
Actually, that is false ... you could not prove such a thing, unless you
force us to disbelieve our own eyes! *To proceed claiming such is only
to invite us to think you daft!

http://www.newscientist.com/article/...ts&nsref=news1...

* ...

Reviewing the URL you supplied. The photograph is not a simple proof
that it appears to be. Camera pictures are notorious
in fooling people into falible interpretatations. However you can
believe what you want. I would point out that I have melded many
things and aproaches
...
Art Unwin KB9MZ..........XG....(UK)

Well, that is simple enough then. *You are to have us disbelieve our own
eyes ... good enough, we have that cleared up.

Regards,
JS

John you can interprete what you want. For me I will await for
somebody
to prove me wrong in the many areas that I have espoused and allow
those that
just want to make nasty remarks go ahead with their agenda. Sooner or
later reason will prevail
and Snakesphere talking in tongues will fade away.. I look forward to
the time that a real guru on radiation
appears on the group to discuss what is salient to the subject
Very best regards
Art Unwin.......KB9MZ........xg (uk)