Art Unwin, KB9MZ wrote:
"What other options do I have for increasing Q other than silver plating
of the copper?"

Art has access to yhe 1955 edition of Terman`s "Electronics and Radio
Engineering", I believe. On page 32 Terman writes:
"In designing single-layer coils, the highest Q in proportion to size is
obtained when the length of the winding is somewhat less than the
diameter of the coil."

It appears Art went in the right direction by increasing the coil
diameter to 12 inches from 4 inches. Nonetheless, his coil is 35 inches
long.

If Art doesn`t want to use a high permeability core, and his coil
already has the required inductance, it seems fewer turns on a larger
diameter form would have a higher Q, so the length of the coil can be
less than the diameter of the coil for the same inductance.

It is good to space the turns by about the diameter of the conductor, or
slightly less. Insulation can be lossy and tends to rise in loss by the
cube of the frequency, so Terman warns about cotton or enamel covered
wire and insulating material used in coil forms at high frequencies. See
page 35 in his 1955 edition.

The existing coil can be measured for inductance, if it is right, and a
coil calculator or program can be consulted to get a coil with better
proportions.

To tune a circuit, a variable capacitor may maintain a better Q than a
variable inductance, (variometer) but at 160 meters, permeability tuning
of the coil should be practical if the power level isn`t too high.

Best regards, Richard Harrison, KB5WZI

If both coil diameter and length are doubled, and number of turns are
reduced to 71% of the number you started with, then you will end-up with the
same inductance as before but the loss resistance will be 71% smaller.

You can continue to do this until radiation resistance becomes the
predominant loss.

Download program SOLNOID2 for coil design and to study these effects.
--
=======================
Regards from Reg, G4FGQ
For Free Radio Design Software
go to http://www.g4fgq.com
=======================


"Art Unwin KB9MZ" wrote in message
...
Richard Clark wrote in message
. ..
On 12 Oct 2003 03:24:10 GMT, oSaddam (Yuri Blanarovich)
wrote:

Art Unwin, KB9MZ wrote:
"The markings are 3600 - 5000 KC."
It was used in a radio or transmitter operating in that range. (German
WW II
SK10?)

Yuri

Hi Yuri,

More probable is Marine DF.

73's
Richard Clark, KB7QHC

After digging into this subject so that I fully understand it I found
that this particular antenna did not work as it should have done. This
'dummy' assumed that I could obtain any Q that I wanted, however
actual inductor was very inefficient for top band use ( very
broadbanded because of losses.)
I went from 4 inch diameter inductance windings to
a 12 inch o/a diameter with 0.6, O.D. copper tubing for a total length
for the inductor of 35 inches. My intention is to now flatten the
copper tubing so the edges to provide minimum interwinding
capacitance.
However I do want the maximum Q available so the antenna is narrow
banded and inductance change is made by lessening the inductance
length for moving around the band.( or possibly the insertion of a
brass rod)

What other options do I have for increasing Q other than silver
plating of the copper?
I opted away from LITZ wire as I figured that top band was too
high a frequency to benefit from its properties.
Any comments or discussion of the subject would be very apreciated
Best regards
Art

Make it as small as possible, with as large as possible conductors.
===========================

Rubbish !

Richard Clark wrote in message . ..
On 19 Oct 2003 16:49:23 -0700, (Art Unwin KB9MZ)
wrote:

What other options do I have for increasing Q other than silver
plating of the copper?

Hi Art,

Make it as small as possible, with as large as possible conductors.
Look at any of the small, tunable, loop antennas on the market.

As a bonus, you also get to participate in the eternal debate about
the voltage found at the ends of a dipole when your own construction
begins arcing big time.

73's
Richard Clark, KB7QHC


Richard,
In my case I need the field around the inductance for coupling
purposes.
To make it smaller a core material would have to be used.
I spoke of flattening the tubing but I am not sure if it would
be worth it to plate or should it be wound ribbon wise as
some of the old Collins inductors or edge wise wound per some
of the commercial inductances.
Going to the large copper winding really showed up as an
improvement in the antenna such that it has wet my appetite !
Regards
Art

Art, I should have added - you must take the opportunity to increase
conductor diameter. You have twice the length of coil with only 70% of the
number of turns to wind along it.

There is NO other way to increase Q of a coil while maintaining the same
inductance.

If you think about it it's fairly obvious.
---
Reg

"Reg Edwards" wrote
If both coil diameter and length are doubled, and number of turns are
reduced to 71% of the number you started with, then you will end-up with
the
same inductance as before but the loss resistance will be 71% smaller.

You can continue to do this until radiation resistance becomes the
predominant loss.

Download program SOLNOID2 for coil design and to study these effects.
--
=======================
Regards from Reg, G4FGQ
For Free Radio Design Software
go to http://www.g4fgq.com
=======================


"Art Unwin KB9MZ" wrote in message
...
Richard Clark wrote in message
. ..
On 12 Oct 2003 03:24:10 GMT, oSaddam (Yuri Blanarovich)
wrote:

Art Unwin, KB9MZ wrote:
"The markings are 3600 - 5000 KC."
It was used in a radio or transmitter operating in that range.
(German
WW II
SK10?)

Yuri

Hi Yuri,

More probable is Marine DF.

73's
Richard Clark, KB7QHC

After digging into this subject so that I fully understand it I found
that this particular antenna did not work as it should have done. This
'dummy' assumed that I could obtain any Q that I wanted, however
actual inductor was very inefficient for top band use ( very
broadbanded because of losses.)
I went from 4 inch diameter inductance windings to
a 12 inch o/a diameter with 0.6, O.D. copper tubing for a total length
for the inductor of 35 inches. My intention is to now flatten the
copper tubing so the edges to provide minimum interwinding
capacitance.
However I do want the maximum Q available so the antenna is narrow
banded and inductance change is made by lessening the inductance
length for moving around the band.( or possibly the insertion of a
brass rod)

What other options do I have for increasing Q other than silver
plating of the copper?
I opted away from LITZ wire as I figured that top band was too
high a frequency to benefit from its properties.
Any comments or discussion of the subject would be very apreciated
Best regards
Art

On 20 Oct 2003 15:19:42 -0700, (Art Unwin KB9MZ)
wrote:
Richard,
In my case I need the field around the inductance for coupling
purposes.

The size of the field has nothing to do with Q.

To make it smaller a core material would have to be used.

Only if you want the same inductance - you didn't ask that, you asked
for more Q.

I spoke of flattening the tubing but I am not sure if it would
be worth it to plate or should it be wound ribbon wise as
some of the old Collins inductors or edge wise wound per some
of the commercial inductances.

Flattening will only increase loss - not Q.

Going to the large copper winding really showed up as an
improvement in the antenna such that it has wet my appetite !
Regards
Art

Increasing copper for the same, or near same inductance is a waste of
time. You have to have started with a pitifully poor example wound on
a old wive's sewing spool to make any gain in that game.

Start with the basic dipole's Q and reckon how much your Q will be
improved = diddly squat. Turn that basic dipole into a small tuned
loop (AKA MFJ or whoever) and watch that Q go through the roof.

However, there is one hidden negative to your wish. Q is not, of and
in itself, a positive thing when optimized beyond all other
characteristics. The crystal in an electric circuit has an
exceptionally high Q and a dipole a mediocre-to-poor one. Which
transmits HF further? If you read your Terman, you will find that
even for a transmitter's tuned final, you DO NOT want the highest Q,
but instead a value between 8 and a dozen. If it were higher, power
would never come out the antenna port.

73's
Richard Clark, KB7QHC

Rubbish !
RTMFQ!

(Richard Harrison) wrote in message ...
Art Unwin, KB9MZ wrote:
"What other options do I have for increasing Q other than silver plating
of the copper?"

Art has access to yhe 1955 edition of Terman`s "Electronics and Radio
Engineering", I believe. On page 32 Terman writes:
"In designing single-layer coils, the highest Q in proportion to size is
obtained when the length of the winding is somewhat less than the
diameter of the coil."

It appears Art went in the right direction by increasing the coil
diameter to 12 inches from 4 inches. Nonetheless, his coil is 35 inches
long.

If Art doesn`t want to use a high permeability core, and his coil
already has the required inductance, it seems fewer turns on a larger
diameter form would have a higher Q, so the length of the coil can be
less than the diameter of the coil for the same inductance.

I recognise the form factor could be better however the change I made
was a huge improvement which I hope to improve by flattening the pipe
in tape winding form.Aty the moment I have two peaks on top band so I
am not ready to change diameters which will come under consideration
when I advance to a lighter construction.

It is good to space the turns by about the diameter of the conductor, or
slightly less. Insulation can be lossy and tends to rise in loss by the
cube of the frequency, so Terman warns about cotton or enamel covered
wire and insulating material used in coil forms at high frequencies. See
page 35 in his 1955 edition.

The existing coil can be measured for inductance, if it is right, and a
coil calculator or program can be consulted to get a coil with better
proportions.

To tune a circuit, a variable capacitor may maintain a better Q than a
variable inductance, (variometer) but at 160 meters, permeability tuning
of the coil should be practical if the power level isn`t too high.
A couple of points here the variometer is only inefficient when you
have a bucking effect, if designed for use in adding inductance I
would suggest that
it would be superior to the use of a capacitor. When you think more
about it the most efficient way is to use just a normal squeezing
action on the inductance length.
Permiability tuning is to be ruled out since the inductance provides
the means
for triple coupling one of which is moved to satisfy 50 ohm impedance
for all frequencies used. Tho I do not use the top band it presents
more of a challenge
than the other bands used with this antenna and it would appear that
one requirement of an antenna for top band is the use of high power
without having to mess with ground radials !

As an aside I seem to remember reading that form factor can exceed the
1:1 ratio
without to much of a problem !!!!
Regards
Art

Best regards, Richard Harrison, KB5WZI

"Reg Edwards" wrote in message ...
Art, I should have added - you must take the opportunity to increase
conductor diameter. You have twice the length of coil with only 70% of the
number of turns to wind along it.

There is NO other way to increase Q of a coil while maintaining the same
inductance.

If you think about it it's fairly obvious.

Reg
my mind is not as alert as yours, many times I will argue for what is
obvious at the time but after several days am forced to change my
mind.
This is a similar case where I am mindful of the bad effects of
capacitance
so I am heading towards keeping the same outside area but reducing
capacitance raising surfaces which by flattening the coil places
the turns closer together.
Since the coils are so large the design forces me to place one side of
the coil close to a fibre glass support which is not good either plus
if I make the turns larger and lighter it will become flimsy unless I
add dielectric loss type supports which may well overtake the losses
in the present design.
All most interesting which is forcing me to think about such a simple
thing such as inductance.
Cheers
Art

---
Reg

"Reg Edwards" wrote
If both coil diameter and length are doubled, and number of turns are
reduced to 71% of the number you started with, then you will end-up with
the
same inductance as before but the loss resistance will be 71% smaller.

You can continue to do this until radiation resistance becomes the
predominant loss.

Download program SOLNOID2 for coil design and to study these effects.
--
=======================
Regards from Reg, G4FGQ
For Free Radio Design Software
go to http://www.g4fgq.com
=======================


"Art Unwin KB9MZ" wrote in message
...
Richard Clark wrote in message
. ..
On 12 Oct 2003 03:24:10 GMT, oSaddam (Yuri Blanarovich)
wrote:

Art Unwin, KB9MZ wrote:
"The markings are 3600 - 5000 KC."
It was used in a radio or transmitter operating in that range.
(German
WW II
SK10?)

Yuri

Hi Yuri,

More probable is Marine DF.

73's
Richard Clark, KB7QHC

After digging into this subject so that I fully understand it I found
that this particular antenna did not work as it should have done. This
'dummy' assumed that I could obtain any Q that I wanted, however
actual inductor was very inefficient for top band use ( very
broadbanded because of losses.)
I went from 4 inch diameter inductance windings to
a 12 inch o/a diameter with 0.6, O.D. copper tubing for a total length
for the inductor of 35 inches. My intention is to now flatten the
copper tubing so the edges to provide minimum interwinding
capacitance.
However I do want the maximum Q available so the antenna is narrow
banded and inductance change is made by lessening the inductance
length for moving around the band.( or possibly the insertion of a
brass rod)

What other options do I have for increasing Q other than silver
plating of the copper?
I opted away from LITZ wire as I figured that top band was too
high a frequency to benefit from its properties.
Any comments or discussion of the subject would be very apreciated
Best regards
Art