Why must only series circuits be considered for radiators?.

What is it about parallel circuits that make them
unsuitable?

Is stagger tuning a parallel circuit ?

Regards
Art

Art KB9MZ wrote:
"Why must only series circuits be considered for radiators?"

It is convenient to follow custom.

Art also wrote:
"What is it about parallel circuits that make them unsuitable?"

We are more familiar with impedance than admittance in most cases due to
our instruction.

A parallel resonsant circuit is a high impedance (low admittance).
A series resonant circuit is a low impedance (high admittance).

For a parallel circuit, Q=R/X.
For a series circuit, Q=X/R.

The series circuit has its equivalent parallel circuit.
The parallel circuit has its equivalent series circuit.
The mathematical conversion from one to the other is simple and shown in
my 19th edition of the ARRL Antenna Book on page 24-12.
(By coincidence the action of 1//4-wave and 1/2-wave transmission line
sections is shown on the next page, 24-13) Commentors on using a
1/2-wave of foreign line inserted in a 50-ohm system, and what the ITT
Handbook says should consult the Antenna Book or some other book that
not only gives you the basic information but also tells you how to use
the information.

Best regards, Richard Harrison, KB5WZI

Art, KB9MZ also wrote:
"Is stagger tuning a parallel circuit?"

Stagger tuning is two or more resonant circuits each tuned to a
different frequency. No restriction that I know of requires parallel
resonance. You can mix and match.

Best regards, Richard Harrison, KB5WZI

On Thu, 04 Mar 2004 18:18:46 GMT, "aunwin"
wrote:

Why must only series circuits be considered for radiators?.

Hi Art,

I don't know if there's a "must" to this. Every series circuit can be
seen as a parallel circuit; and on the flip side, every parallel
circuit can be seen as a series circuit. It is all a matter of where
you put your leads to drive/measure/load/receive.... The same
components vary only slightly in frequency from their being series
resonant or parallel resonate. Without that
drive/measure/load/receive path, there is no energy transfer and power
consumption is all strictly a matter of component ohmic loss.

What is it about parallel circuits that make them unsuitable?

They are used every day to load up halfwave verticals, which in turn
are also parallel equivalent circuits. The input to the parallel
interface is performed through divider action (usually a tapped coil,
but could be through a capacitor divider).

Is stagger tuning a parallel circuit ?

No, but it could be. Stagger tuning, by convention is a chain of
separately tuned circuits, be they RC, RL, or LC (or, of course RLC).
One RC or RL circuit exhibits a 6dB/Octave or 10dB/Decade roll-off.
One LC circuit exhibits twice that or a 12dB/Octave or 20dB/Decade
roll-off. Again, it is all a matter of connections for the identical
components (which will show a slight shift in parallel to series
resonance frequency - which is to say it is application dependent).

Two RC or two RL, or one RC with one RL in cascade constitute "stagger
tuning" irrespective of what frequencies their roll-off occur at (this
sets the stage for Bandwidth) and their sum contribution equal roughly
one LC circuit (which does not qualify as "stagger tuned") as long as
they share the same characteristic frequency (where the roll-off
occurs which is generally defined at the 3dB inflection).

Now, as to the expression "roll-off" used liberally above. All such
circuits may be called "de-emphasis" (where roll-off is evident) or
"pre-emphasis" (where roll-up would be more descriptive). The
application is strictly a matter of where the drive is applied, and
where the load takes its output.

73's
Richard Clark, KB7QHC

This is silly......... and you can't blame this on web tv.

Not one answer to any of the questions that anybody can hang their hat on!,
Just talking out loud from a book that fell open at a page. When are you
going to make some sense with your responses, most of us know and use the
formulas that you keep regurgitating but only when they are relavent.

Did your posting get cut short and the answers destroyed or did you forget
why you are posting?

There are three simple questions only. Simple answers should
suffice............. if........ you know your stuff.
If you find the answers to the simple questions in a book then please let me
know and I can read it in context for myself and I will thank you..

When Johny Carson gave the answers first on his show and one then had to
find a suitable question for it it was funny first time around only, so you
should quit doing it.
If you don't know the answers then it O.K. you don't have to respond if you
don't know, certainly better than verbal diarrea.
Art


"Richard Harrison" wrote in message
...
Art KB9MZ wrote:
"Why must only series circuits be considered for radiators?"

It is convenient to follow custom.

Art also wrote:
"What is it about parallel circuits that make them unsuitable?"

We are more familiar with impedance than admittance in most cases due to
our instruction.

A parallel resonsant circuit is a high impedance (low admittance).
A series resonant circuit is a low impedance (high admittance).

For a parallel circuit, Q=R/X.
For a series circuit, Q=X/R.

The series circuit has its equivalent parallel circuit.
The parallel circuit has its equivalent series circuit.
The mathematical conversion from one to the other is simple and shown in
my 19th edition of the ARRL Antenna Book on page 24-12.
(By coincidence the action of 1//4-wave and 1/2-wave transmission line
sections is shown on the next page, 24-13) Commentors on using a
1/2-wave of foreign line inserted in a 50-ohm system, and what the ITT
Handbook says should consult the Antenna Book or some other book that
not only gives you the basic information but also tells you how to use
the information.

Best regards, Richard Harrison, KB5WZI

"aunwin" wrote in message
news:aqK1c.176934$jk2.646180@attbi_s53...
Why must only series circuits be considered for radiators?.

They aren't. Series circuits are series circuits , radiators are
radiators. They are different things.

What is it about parallel circuits that make them
unsuitable?

Suitable for what?


Is stagger tuning a parallel circuit ?

Regards
Art

This question needs to be finished. A parallel circuit can't be stagger
tuned.


Troll??

--
Steve N, K,9;d, c. i My email has no u's.

"Richard Clark" wrote in message
...
On Thu, 04 Mar 2004 18:18:46 GMT, "aunwin"
wrote:

Why must only series circuits be considered for radiators?.

Hi Art,

I don't know if there's a "must" to this.

At last.... at last somebody said
'I don't know'
Perhaps Walter will now say he doesn't know!


Every series circuit can be
seen as a parallel circuit; and on the flip side, every parallel
circuit can be seen as a series circuit. It is all a matter of where
you put your leads to drive/measure/load/receive.... The same
components vary only slightly in frequency from their being series
resonant or parallel resonate. Without that
drive/measure/load/receive path, there is no energy transfer and power
consumption is all strictly a matter of component ohmic loss.

Yes, partially understood , so to the question......



What is it about parallel circuits that make them unsuitable?

They are used every day to load up halfwave verticals, which in turn
are also parallel equivalent circuits.

Did you mean that? A halfwave vertical is a parallel circuit!

The input to the parallel
interface is performed through divider action (usually a tapped coil,
but could be through a capacitor divider).

Yes I know that but the question did say antennas didn't it?

You gave an answer to a question that was not asked. What you are refering
to is not for its radiation attributes is it? I hope we are not going into a
multi heading thread mode in less than 12 hours.


Is stagger tuning a parallel circuit ?

No, but it could be. Stagger tuning, by convention is a chain of
separately tuned circuits, be they RC, RL, or LC (or, of course RLC).

You mentioned the all important word of "tuned" so all of the above are
parallel circuits....right?

One RC or RL circuit exhibits a 6dB/Octave or 10dB/Decade roll-off.
One LC circuit exhibits twice that or a 12dB/Octave or 20dB/Decade
roll-off. Again, it is all a matter of connections for the identical
components (which will show a slight shift in parallel to series
resonance frequency - which is to say it is application
dependent).

I totally miss this point and probably the blame is mine. I think you are
saying that yes, they are parallel circuits, but you have an exception that
you want to point out i.e.slight shift in parallel to series...........

Not sure if you are saying 'yes'. I personaly think it is a parallel
circuit to which I would answer 'yes'.
Are you asking for some wriggle room? Two elements that are physically
separated is much too hard for me to describe as a series circuit. So I ask
the question in the context of the first two questions to prevent answers to
the like of 'just habit.'
Now I am not being awkward, believe me or I would not have responded. Force
12 has stagger tuning, if it is series devised then it gives more ammo to
the 'do not use parallel circuits for antennas' argument which seems to be
prevalent with antenna experts.

Two RC or two RL, or one RC with one RL in cascade constitute "stagger
tuning" irrespective of what frequencies their roll-off occur at (this
sets the stage for Bandwidth) and their sum contribution equal roughly
one LC circuit (which does not qualify as "stagger tuned") as long as
they share the same characteristic frequency (where the roll-off
occurs which is generally defined at the 3dB inflection).

Now, as to the expression "roll-off" used liberally above. All such
circuits may be called "de-emphasis" (where roll-off is evident) or
"pre-emphasis" (where roll-up would be more descriptive). The
application is strictly a matter of where the drive is applied, and
where the load takes its output.

I lost the point that you had in mind with the above and I wish you had not
mentioned bandwidth since it will bring another fork to the thread

73's
Richard Clark, KB7QHC

No rudeness intended anywhere Rich.. I seriously need reasonable specific
answers before I spend a lot of money.
Art

Steve, ask me what you want to know about the posting. I am trying to keep
it short and to the point so I assumed ,maybe wrongly, that most were
conversant with antennas. The shorter the question the less mucking around
and surely, only an expert can provide the answers.
Regards
Art
"Steve Nosko" wrote in message
...

"aunwin" wrote in message
news:aqK1c.176934$jk2.646180@attbi_s53...
Why must only series circuits be considered for radiators?.

They aren't. Series circuits are series circuits , radiators are
radiators. They are different things.

What is it about parallel circuits that make them
unsuitable?

Suitable for what?


Is stagger tuning a parallel circuit ?

Regards
Art

This question needs to be finished. A parallel circuit can't be
stagger
tuned.


Troll??

--
Steve N, K,9;d, c. i My email has no u's.

Richard I am reading your posts because I initiated the post
So for you I will pose it differently so you can quote from all your books
legitimately. For you just one question only so you don't wander off as you
sometimes do. And yes I will respond because I initiated the thread,yes I
will read it.

If radio was just thought of today give the pros and cons between a series
circuit and a parallel circuit from which to base a radiator ? Don't put
down 'tradition' or 'habit' just put a list of pro's and con for each side .
Just to give you a start a series circuit radiator is a dipole. And we will
say a parallel circuit radiator is one with at least one capacitive lumped
circuit and one inductive lumped circuit in parallel. Keep it simple, don't
twist the question around because you know of a special case. Just simple
pro and con and you can quote from a book if it provides specific pro and
con which will keep things in perspective i.e we know the formulae so there
is no need to give your fingers a workout.
Here is a start
A dipole provides a lot of signals at the same time( good)
A parallel circuit can only supply one signal at a time (bad )
Get the idea?
There, I am giving you the benefit of being a antenna guru that has the
personal knoweledge that the question obviously requires and where a lot of
people are hopelessly adrift.
The question now is a bit long but hopefully for you it will be beneficial.
Art

"Richard Harrison" wrote in message
...
Art, KB9MZ also wrote:
"Is stagger tuning a parallel circuit?"

Stagger tuning is two or more resonant circuits each tuned to a
different frequency. No restriction that I know of requires parallel
resonance. You can mix and match.
Two circuits each with a different frequency will couple to each other via
back EMF and thus makes it a parallel circuit. You can call it under
coupled, over coupled or just coupled but it is a parallel circuit none the
less. But let's not get side tracked because you don't
know......'restrictions" just factual pro and con or you will wander off
again.
Art

Best regards, Richard Harrison, KB5WZI

On Thu, 04 Mar 2004 21:36:22 GMT, "aunwin"
wrote:
What is it about parallel circuits that make them unsuitable?

They are used every day to load up halfwave verticals, which in turn
are also parallel equivalent circuits.

Did you mean that? A halfwave vertical is a parallel circuit!

That is the longstanding convention. Same thing applies to a one
wavelength dipole. All such are the basis of the J-Pole and the Zepp
(when you strip away their matching sections).

The input to the parallel
interface is performed through divider action (usually a tapped coil,
but could be through a capacitor divider).

Yes I know that but the question did say antennas didn't it?

Antennas don't find much application without some method of driving
them. Very few successful halfwave designs exist without matching.
This is because the halfwave vertical, looking like a parallel
circuit, has a considerable amount of Z that rejects power (unless
your rig is a van-de-graff generator). Adding the radiation
resistance to a high Z hardly allows any current into the radiation
resistance. On the other hand, a quarterwave looks like a series
resonant circuit with very low Z, and thus the radiation resistance
absorbs all the power applied. Very simple electronics.

One solution to feeding the halfwave tall vertical is to break it in
half and feed it half way up (where the two sections look like series
resonant, low Z elements feeding the radiation resistance without much
impediment). This is simplified, of course, but it illustrates how
the same circuit can support either a series resonant or parallel
resonant description determined only by the topology of connection.

You gave an answer to a question that was not asked. What you are refering
to is not for its radiation attributes is it? I hope we are not going into a
multi heading thread mode in less than 12 hours.

Matching sections to the J-Pole and the Zepp are contributors to
radiation due to the unbalanced nature of those antennas designs. How
much they contribute is perhaps arguable, but when they are built in
without care, their contribution cannot be denied. The matching
circuits contain both circulating currents and common mode currents.
The common mode currents, as a function of the physical length
compared to wavelength, offer radiation. The radiation may aid, or it
may hinder, but it is there none the less.

Is stagger tuning a parallel circuit ?

No, but it could be. Stagger tuning, by convention is a chain of
separately tuned circuits, be they RC, RL, or LC (or, of course RLC).

You mentioned the all important word of "tuned" so all of the above are
parallel circuits....right?

No, but they could be. The application of drive and loads determine
the topology:

One RC or RL circuit exhibits a 6dB/Octave or 10dB/Decade roll-off.
One LC circuit exhibits twice that or a 12dB/Octave or 20dB/Decade
roll-off. Again, it is all a matter of connections for the identical
components (which will show a slight shift in parallel to series
resonance frequency - which is to say it is application
dependent).

I totally miss this point and probably the blame is mine. I think you are
saying that yes, they are parallel circuits, but you have an exception that
you want to point out i.e.slight shift in parallel to series...........

No, they are NOT parallel - they could be, but there is nothing
inherently parallel and it all depends on the drive and load applied.

Not sure if you are saying 'yes'. I personaly think it is a parallel
circuit to which I would answer 'yes'.

No, they are NOT parallel - they could be, but there is nothing
inherently parallel and it all depends on the drive and load applied.

Force
12 has stagger tuning, if it is series devised then it gives more ammo to
the 'do not use parallel circuits for antennas' argument which seems to be
prevalent with antenna experts.

Force 12 makes many antennas, I will presume you are speaking of some
beam array. Stagger tuning, in that sense, is much akin to the
reflector, radiator, director relationship of the yagi. That design
is stagger tuned, but such stagger tuning is to accomplish various
delays that aid gain in one direction, and negate it in another. Such
stagger tuning is not directly engaged upon for the purpose of
bandwidth, although it may have indirect consequences. I have a beam
array for 440 that employs an LPDA radiator tied into the conventional
reflector and directors. As such it performs stagger tuning for the
purpose of beam forming AND bandwidth.

The elements in the Fan Dipole or the Log Periodic Dipole Array more
closely align to the conventional meaning of stagger tuning. The Fan
Dipole is the most obvious case. It's metaphor would be as many
parallel, series resonant circuits as there are elements, each
slightly tuned off from the other, all feeding in series and combining
in parallel to average a wider bandwidth response than any single
series resonant element.

73's
Richard Clark, KB7QHC