How to design an Interesting inductor

[Phil Hobbs]

On 8/20/19 3:04 PM, amdx wrote:

On 8/20/2019 11:28 AM, Phil Hobbs wrote:
On 8/20/19 4:41 AM, Clive Arthur wrote:
On 20/08/2019 01:53, amdx wrote:
I'd like to have a Variable 100uh inductor, that is controlled
to full saturation with dc through the 100uh coil. I see some
two winding coils, but the dc control winding has huge
inductance. Working range 500kHz to 4MHz. Is this possible?

Thanks for your thoughts, Mikek

Some RM cores and pot cores have a central hole through which you
could wind your 100uH, and the DC winding goes on the bobbin...

https://uk.farnell.com/ferroxcube/rm10-i-3c95/ferrite-core-rm-i-3c95/dp/2103458?st=rm%20core



...this is a 5.5uH core so approx 4 turns for 100uH if it were
wound on the bobbin, I don't know how many if wound through the
hole, but I'd guess it would be similar. I'd try to grind the
hole edges to take off the sharp edge if possible.

Cheers

One minor tweak to that idea is to run an odd number of half-turns
on the bobbin, and use a high-mu pot core with an adjustable centre
gap.

The extra half-turn will generate a large field going round the
outside of the core (avoiding the post) and so will saturate it
fairly readily.

Cheers

Phil Hobbs


Can you explain physically how that would look?

With pot cores you usually twist the two leads together and bring them
out through a slot in the side of the core. If there are two or more
slots, the wire goes in through one slot and comes out through a second
one, 180 degrees away.

My only experience with half turns is, we put a 4-1/2 turn inductor
in a medium power circuit. The coil over heated, 4 turns were fine, 5
turns were fine, we never did a half turn inductor again. OH wait you
only mean a single half turn as we did above, so if I need 12 turns
make it 12-1/2 turns. Is that correct? Any way to do 1/2 turn on a
toroid?

Nope. It's just the threading count.

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 8/21/19 7:50 PM, amdx wrote:

On 8/21/2019 4:45 PM, Phil Hobbs wrote:
On 8/20/19 3:04 PM, amdx wrote:
On 8/20/2019 11:28 AM, Phil Hobbs wrote:
On 8/20/19 4:41 AM, Clive Arthur wrote:
On 20/08/2019 01:53, amdx wrote:
I'd like to have a Variable 100uh inductor, that is controlled
to full saturation with dc through the 100uh coil. I see some
two winding coils, but the dc control winding has huge inductance.
Working range 500kHz to 4MHz. Is this possible?

Thanks for your thoughts, Mikek

Some RM cores and pot cores have a central hole through which you
 could wind your 100uH, and the DC winding goes on the bobbin...

https://uk.farnell.com/ferroxcube/rm10-i-3c95/ferrite-core-rm-i-3c95/dp/2103458?st=rm%20core




...this is a 5.5uH core so approx 4 turns for 100uH if it were
wound on the bobbin, I don't know how many if wound through the
hole, but I'd guess it would be similar.  I'd try to grind the
hole edges to take off the sharp edge if possible.

Cheers

One minor tweak to that idea is to run an odd number of half-turns
on the bobbin, and use a high-mu pot core with an adjustable centre
gap.

The extra half-turn will generate a large field going round the
outside of the core (avoiding the post) and so will saturate it
fairly readily.

Cheers

Phil Hobbs


Can you explain physically how that would look?

With pot cores you usually twist the two leads together and bring them
out through a slot in the side of the core.  If there are two or more
slots, the wire goes in through one slot and comes out through a second
one, 180 degrees away.


My only experience with half turns is, we put a 4-1/2 turn inductor
in a medium power circuit. The coil over heated, 4 turns were fine, 5
turns were fine, we never did a half turn inductor again. OH wait you
only mean a single half turn as we did above, so if I need 12 turns
make it 12-1/2 turns. Is that correct? Any way to do 1/2 turn on a
toroid?

Nope.  It's just the threading count.

Thread count? Huh?

 ^  Room for explanation ^

Not like bed sheets.

The inductance contributed by the toroid goes as N**2, where N is the
number of times the wire goes through the aperture of the toroid. No
half turns need apply.

 Just because I left out the details, my 4-1/2 turn inductor was a
potcore inductor, easy to add that 1/2 turn.

Right. And that half turn completely changes the saturation behaviour,
at least if the centre post has a gap.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[amdx]

On 8/21/2019 4:45 PM, Phil Hobbs wrote:

On 8/20/19 3:04 PM, amdx wrote:
On 8/20/2019 11:28 AM, Phil Hobbs wrote:
On 8/20/19 4:41 AM, Clive Arthur wrote:
On 20/08/2019 01:53, amdx wrote:
I'd like to have a Variable 100uh inductor, that is controlled
to full saturation with dc through the 100uh coil. I see some
two winding coils, but the dc control winding has huge inductance.
Working range 500kHz to 4MHz. Is this possible?

Thanks for your thoughts, Mikek

Some RM cores and pot cores have a central hole through which you
 could wind your 100uH, and the DC winding goes on the bobbin...

https://uk.farnell.com/ferroxcube/rm10-i-3c95/ferrite-core-rm-i-3c95/dp/2103458?st=rm%20core




...this is a 5.5uH core so approx 4 turns for 100uH if it were
wound on the bobbin, I don't know how many if wound through the
hole, but I'd guess it would be similar.  I'd try to grind the
hole edges to take off the sharp edge if possible.

Cheers

One minor tweak to that idea is to run an odd number of half-turns
on the bobbin, and use a high-mu pot core with an adjustable centre
gap.

The extra half-turn will generate a large field going round the
outside of the core (avoiding the post) and so will saturate it
fairly readily.

Cheers

Phil Hobbs


Can you explain physically how that would look?

With pot cores you usually twist the two leads together and bring them
out through a slot in the side of the core.  If there are two or more
slots, the wire goes in through one slot and comes out through a second
one, 180 degrees away.


My only experience with half turns is, we put a 4-1/2 turn inductor
in a medium power circuit. The coil over heated, 4 turns were fine, 5
turns were fine, we never did a half turn inductor again. OH wait you
only mean a single half turn as we did above, so if I need 12 turns
make it 12-1/2 turns. Is that correct? Any way to do 1/2 turn on a
toroid?

Nope.  It's just the threading count.

Cheers

Phil Hobbs

Thread count? Huh?

^ Room for explanation ^

Just because I left out the details, my 4-1/2 turn inductor was a
potcore inductor, easy to add that 1/2 turn.

 

[Phil Hobbs]

On 8/21/19 8:57 PM, jlarkin@highlandsniptechnology.com wrote:

On Wed, 21 Aug 2019 20:36:36 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 8/21/19 7:50 PM, amdx wrote:
On 8/21/2019 4:45 PM, Phil Hobbs wrote:
On 8/20/19 3:04 PM, amdx wrote:
On 8/20/2019 11:28 AM, Phil Hobbs wrote:
On 8/20/19 4:41 AM, Clive Arthur wrote:
On 20/08/2019 01:53, amdx wrote:
I'd like to have a Variable 100uh inductor, that is controlled
to full saturation with dc through the 100uh coil. I see some
two winding coils, but the dc control winding has huge inductance.
Working range 500kHz to 4MHz. Is this possible?

Thanks for your thoughts, Mikek

Some RM cores and pot cores have a central hole through which you
 could wind your 100uH, and the DC winding goes on the bobbin...

https://uk.farnell.com/ferroxcube/rm10-i-3c95/ferrite-core-rm-i-3c95/dp/2103458?st=rm%20core




...this is a 5.5uH core so approx 4 turns for 100uH if it were
wound on the bobbin, I don't know how many if wound through the
hole, but I'd guess it would be similar.  I'd try to grind the
hole edges to take off the sharp edge if possible.

Cheers

One minor tweak to that idea is to run an odd number of half-turns
on the bobbin, and use a high-mu pot core with an adjustable centre
gap.

The extra half-turn will generate a large field going round the
outside of the core (avoiding the post) and so will saturate it
fairly readily.

Cheers

Phil Hobbs


Can you explain physically how that would look?

With pot cores you usually twist the two leads together and bring them
out through a slot in the side of the core.  If there are two or more
slots, the wire goes in through one slot and comes out through a second
one, 180 degrees away.


My only experience with half turns is, we put a 4-1/2 turn inductor
in a medium power circuit. The coil over heated, 4 turns were fine, 5
turns were fine, we never did a half turn inductor again. OH wait you
only mean a single half turn as we did above, so if I need 12 turns
make it 12-1/2 turns. Is that correct? Any way to do 1/2 turn on a
toroid?

Nope.  It's just the threading count.

Thread count? Huh?

 ^  Room for explanation ^

Not like bed sheets.

The inductance contributed by the toroid goes as N**2, where N is the
number of times the wire goes through the aperture of the toroid. No
half turns need apply.



A half turn in a pot core can have impressively bad effects.


Yup. Or in this case, potentially useful ones.

Cheers

Phil Hobbs



--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

On Wed, 21 Aug 2019 20:36:36 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 8/21/19 7:50 PM, amdx wrote:
On 8/21/2019 4:45 PM, Phil Hobbs wrote:
On 8/20/19 3:04 PM, amdx wrote:
On 8/20/2019 11:28 AM, Phil Hobbs wrote:
On 8/20/19 4:41 AM, Clive Arthur wrote:
On 20/08/2019 01:53, amdx wrote:
I'd like to have a Variable 100uh inductor, that is controlled
to full saturation with dc through the 100uh coil. I see some
two winding coils, but the dc control winding has huge inductance.
Working range 500kHz to 4MHz. Is this possible?

Thanks for your thoughts, Mikek

Some RM cores and pot cores have a central hole through which you
 could wind your 100uH, and the DC winding goes on the bobbin...

https://uk.farnell.com/ferroxcube/rm10-i-3c95/ferrite-core-rm-i-3c95/dp/2103458?st=rm%20core




...this is a 5.5uH core so approx 4 turns for 100uH if it were
wound on the bobbin, I don't know how many if wound through the
hole, but I'd guess it would be similar.  I'd try to grind the
hole edges to take off the sharp edge if possible.

Cheers

One minor tweak to that idea is to run an odd number of half-turns
on the bobbin, and use a high-mu pot core with an adjustable centre
gap.

The extra half-turn will generate a large field going round the
outside of the core (avoiding the post) and so will saturate it
fairly readily.

Cheers

Phil Hobbs


Can you explain physically how that would look?

With pot cores you usually twist the two leads together and bring them
out through a slot in the side of the core.  If there are two or more
slots, the wire goes in through one slot and comes out through a second
one, 180 degrees away.


My only experience with half turns is, we put a 4-1/2 turn inductor
in a medium power circuit. The coil over heated, 4 turns were fine, 5
turns were fine, we never did a half turn inductor again. OH wait you
only mean a single half turn as we did above, so if I need 12 turns
make it 12-1/2 turns. Is that correct? Any way to do 1/2 turn on a
toroid?

Nope.  It's just the threading count.

Thread count? Huh?

 ^  Room for explanation ^

Not like bed sheets.

The inductance contributed by the toroid goes as N**2, where N is the
number of times the wire goes through the aperture of the toroid. No
half turns need apply.

A half turn in a pot core can have impressively bad effects.

 

[amdx]

On 8/21/2019 7:36 PM, Phil Hobbs wrote:

On 8/21/19 7:50 PM, amdx wrote:
On 8/21/2019 4:45 PM, Phil Hobbs wrote:
On 8/20/19 3:04 PM, amdx wrote:
On 8/20/2019 11:28 AM, Phil Hobbs wrote:
On 8/20/19 4:41 AM, Clive Arthur wrote:
On 20/08/2019 01:53, amdx wrote:
I'd like to have a Variable 100uh inductor, that is controlled
to full saturation with dc through the 100uh coil. I see some
two winding coils, but the dc control winding has huge
inductance. Working range 500kHz to 4MHz. Is this possible?

Thanks for your thoughts, Mikek

Some RM cores and pot cores have a central hole through which you
 could wind your 100uH, and the DC winding goes on the bobbin...

https://uk.farnell.com/ferroxcube/rm10-i-3c95/ferrite-core-rm-i-3c95/dp/2103458?st=rm%20core




...this is a 5.5uH core so approx 4 turns for 100uH if it were
wound on the bobbin, I don't know how many if wound through the
hole, but I'd guess it would be similar.  I'd try to grind the
hole edges to take off the sharp edge if possible.

Cheers

One minor tweak to that idea is to run an odd number of half-turns
on the bobbin, and use a high-mu pot core with an adjustable centre
gap.

The extra half-turn will generate a large field going round the
outside of the core (avoiding the post) and so will saturate it
fairly readily.

Cheers

Phil Hobbs


Can you explain physically how that would look?

With pot cores you usually twist the two leads together and bring them
out through a slot in the side of the core.  If there are two or more
slots, the wire goes in through one slot and comes out through a second
one, 180 degrees away.


My only experience with half turns is, we put a 4-1/2 turn inductor
in a medium power circuit. The coil over heated, 4 turns were fine, 5
turns were fine, we never did a half turn inductor again. OH wait you
only mean a single half turn as we did above, so if I need 12 turns
make it 12-1/2 turns. Is that correct? Any way to do 1/2 turn on a
toroid?

Nope.  It's just the threading count.

Thread count? Huh?

  ^  Room for explanation ^

Not like bed sheets.

The inductance contributed by the toroid goes as N**2, where N is the
number of times the wire goes through the aperture of the toroid.  No
half turns need apply.



  Just because I left out the details, my 4-1/2 turn inductor was a
potcore inductor, easy to add that 1/2 turn.

Right.  And that half turn completely changes the saturation behaviour,
at least if the centre post has a gap.

Cheers

Phil Hobbs

I found something I can at least try.
https://www.dropbox.com/s/ogpkx881d33m9mb/saturable%20core%20inductor%20db%20improved.jpg?dl=0

I got a strong magnet to change the inductance from 100uH to 4.6uH.
Mikek

 

[Tim Williams]

"amdx" <nojunk@knology.net> wrote in message
news:qjhg76$qde$1@dont-email.me...

Can you explain physically how that would look? My only experience with
half turns is, we put a 4-1/2 turn inductor in a medium power circuit.
The coil over heated, 4 turns were fine, 5 turns were fine, we never did
a half turn inductor again.
OH wait you only mean a single half turn as we did above, so if I need 12
turns make it 12-1/2 turns. Is that correct?
Any way to do 1/2 turn on a toroid?

I wrote an article in part discussing that, recently:
https://www.seventransistorlabs.com/DC-DC_RE/index.html
Measurements are included, showing the imbalance in external flux.

The correct way to make half turns is to put a figure-eight winding on the
legs to enforce flux balance. These can even be intentionally unbalanced
(say 1:2), to get even more interesting fractions of turns (1/3, 1/4, etc.).
With a corresponding hit in Phi_sat of course, because the one side
saturates first. I link to a Unitrode appnote which discusses this.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

 

On Tue, 20 Aug 2019 12:47:54 -0500, amdx <nojunk@knology.net> wrote:

On 8/20/2019 11:11 AM, Tim Williams wrote:
"amdx" <nojunk@knology.net> wrote in message
news:qjgbfo$1la$1@dont-email.me...
In previous responses I gave the proposed use is for a
"Beverage on Ground" antenna.

I have some understanding of normal Beverages, but are there reliable
comparative data for BOG or slinky antennas ? Until there are some
reliable comporarative and calibrated comparison betwen real Beverages
an BOGs and slinki antennas I really do not want to mess with them.

 I had a GOG before and used a beds that had a Q of 1 or 2.
 so if I could get 20 it would be better.

The main selling point of Beverages is that it is wide band, you
definitely _do_not_ want any high-Q (i.e. low bandwidth) constructs.

What power level?  Frequency range?

Tim

Man, what time did I write the above?
What I meant to say was,
I had a BOG before and used a bedds that had a Q of 1 or 2.
so if I could get 20 it would be better.

It's for a receive only antenna, so microwatts, maybe milliwatts.
500kHz to 4 MHz.

Mikek

Another possible solution,
Is there a combination of L's and Cs the would approximate such an L
reduction over frequency?

 

On Wed, 21 Aug 2019 16:52:01 -0500, amdx <nojunk@knology.net> wrote:

On 8/20/2019 10:00 PM, amdx wrote:
On 8/20/2019 12:47 PM, amdx wrote:
On 8/20/2019 11:11 AM, Tim Williams wrote:
"amdx" <nojunk@knology.net> wrote in message
news:qjgbfo$1la$1@dont-email.me...
In previous responses I gave the proposed use is for a
"Beverage on Ground" antenna.
 I had a GOG before and used a beds that had a Q of 1 or 2.
 so if I could get 20 it would be better.

What power level?  Frequency range?

Tim

  Man, what time did I write the above?
What I meant to say was,
I had a BOG before and used a bedds that had a Q of 1 or 2.
   so if I could get 20 it would be better.

It's for a receive only antenna, so microwatts, maybe milliwatts.
500kHz to 4 MHz.

                                  Mikek

  Another possible solution,
  Is there a combination of L's and Cs the would approximate such an L
reduction over frequency?

 One of those times, I could see you posted but nothing in the post, so
I went to google groups.

  Man, what time did I write the above?
What I meant to say was,
I had a BOG before and used a bedds that had a Q of 1 or 2.
   so if I could get 20 it would be better.

I still don't know what you're writing.  It ain't English...

Well, "bog" aside.  But that means something different in English
English.
;-)

I'll try to get a good nights sleep tonight!
 BOG = Beverage On Ground
 bedds was supposed to be beads/sleeves which were actually a #73
binocular core that I only used one hole of. I just passed the antenna
wire through it. About 24 ohms R and 42 ohm XL at 1MHz.



It's for a receive only antenna, so microwatts, maybe milliwatts.
500kHz to 4 MHz.

What about just low noise JFETs?  It's not like you need any antenna
gain in
those bands.

Well, maybe, but usually the receive has enough gain, the bog signal is
down, maybe -25dbi to -40dbi.
But that is not the problem, by adjusting characteristics with frequency
you can narrow the beam width and increase the front to back ratio.
btw, I do have a high input impedance FET follower with low output
impedance, no gain but you do unload the antenna so get 3db. I'll be
trying that.

I had the Gain from adding a FET follower incorrect, unloading the
antenna gets you 3 db, then not have a 450ohm:50ohm impedance matching
(step down) transformer gives you another ~10db. Probably not quite as
much on a BOG because it has a lower feed impedance.
https://www.okdxf.eu/lankford/J310%20-%20J271%20FET%20Follower.pdf

Ignore the chest pounding by Lankford he had a spat going with Trask,
may still have.
Mikek

A simple passive stage (such as a transformer), can have voltage or
current gain but the power gain is at best 0 dB. To have real power
gain, you need an active device.

 

On Wed, 21 Aug 2019 14:37:58 -0500, amdx <nojunk@knology.net> wrote:

On 8/21/2019 11:10 AM, legg wrote:
On Wed, 21 Aug 2019 07:59:39 -0500, amdx <nojunk@knology.net> wrote:

On 8/21/2019 1:55 AM, Jasen Betts wrote:
On 2019-08-21, legg <legg@nospam.magma.ca> wrote:
On Tue, 20 Aug 2019 14:06:17 -0500, amdx <nojunk@knology.net> wrote:

On 8/20/2019 11:41 AM, legg wrote:
On Mon, 19 Aug 2019 19:53:28 -0500, amdx <nojunk@knology.net> wrote:

I'd like to have a Variable 100uh inductor, that is controlled to full
saturation with dc through the 100uh coil.
I see some two winding coils, but the dc control winding has huge
inductance. Working range 500kHz to 4MHz.
Is this possible?

Thanks for your thoughts, Mikek
A cpnventional current-controlled inductor has two magnetic paths that
are configured to carry antiphase windings, with the third 'inductor
winding sharing both. The control windings' AC flux, from the third
winding, cancels out.

You can do this with an e-core (control windings on outer arms), two
toroids (each with control winding - sandwitched to support single
'inductor' winding around both) or solenoids (two solenoid cores
support control windings, 'inductor' wound around both.).

RL


As state previously, My question was not ask well, I only want one
winding with both ac and the dc to saturate it.

Thanks, Mikek

An ideal current source is easy to simulate, but in real life, it's
voltage compliance limits, stray loading and real power loss will set
limits on what you can do.

The conventional multiple winding is the more realistic approach.

Parasitics from the lower-powered control circuit are also easier to
isolate.

RL

AIUI this is for a recieve antenna so the AC signal will be failrly
small, I expect that the current source only needs enough compliance
to overcome earth resistance and a little headroom.

It is a receive only antenna.
And if you are suggesting a dc return through the earth, that was not
part of my plan. I think electrolysis would be a problem..
So a two wire dc system.
Mikek


I don't see such a restriction to be a valid design goal in a new
product. What's the selling point? Electrolysis????? Even in a
retrofit, the addition of an external field-generating winding might
be easiest.

A modest current source can be decoupled from a tuned/tuning circuit,
over a known frequency range using a series choke. In small signal
circuitry, it's an issue you'd try to avoid, as resistors do the job
pretty well at low current.

A tuned circuit with an ungrounded terminal might benefit from a
re-examination of the schematic. Ground is, after all, everywhere. You
should use that feature, rather than compound it's potential problems.

If the aim is repeatable, calibratable 'L' values, I forsee a host of
issues with this technique.

Closed circuit, low frequency magnetics have to be re-evaluated for
function, when located within close proximity to large magnets, but a
magnet on a stick doesn't fit in well with typical solid-state circuit
aims.

RL


Start here.
https://www.w8ji.com/beverages.htm

Then see Loaded beverages here,
https://www.w8ji.com/slinky_and_loaded_beverages.htm

Now, I want to load a beverage on ground.
I don't have enough room for BOG long enough to have good
directionality in the BCB, therefore, I want to load it,

Beverages are nice, _if_ you have space for 0.5 - 2 wavelengths long
wires. If you don't have that space, you should seriously really study
other antenna alternatives.

reducing the VF and changing the pattern.
If it is loaded to make it directional at 1MHz then it doesn't look
good at 4 MHz, So I want variable inductors.

So a 150 m long Beverage is 0.5 wavelengths at 1 MHz and 2 wavelengths
at 4 MHz.

Have you considered installing a grounding resistor at 38 m (for 4
MHz) and at 75 m (for 2 MHz) and final termination resistance at 150 m
(for 1 MHz) ? The intermediate grounding resistors are then selected
by relays. Feed some audio tones along the wire to activate those
intermediate relays (with some audio frequency selective rectifiers).

It doesn't look good, the mixing products concerns me and finding a
material or combination that I can cause to reduce inductance as
frequency increases is not jumping out.

If you use relays to select grounding point no need to worry about
ferrite nonlinearity or mixing products.

Thanks, Mikek

 

[amdx]

On 8/22/2019 12:43 PM, upsidedown@downunder.com wrote:

On Tue, 20 Aug 2019 12:47:54 -0500, amdx <nojunk@knology.net> wrote:

On 8/20/2019 11:11 AM, Tim Williams wrote:
"amdx" <nojunk@knology.net> wrote in message
news:qjgbfo$1la$1@dont-email.me...
In previous responses I gave the proposed use is for a
"Beverage on Ground" antenna.

I have some understanding of normal Beverages, but are there reliable
comparative data for BOG or slinky antennas ? Until there are some
reliable comporarative and calibrated comparison between real Beverages
and BOGs and slinky antennas I really do not want to mess with them.

If I had 1000ft to put up a Beverage, I would. I have a 10ft by
250ft area that is great for a Bog. I don't know any comparison papers.
I just know I had 3 antennas, The BOG was the best listening to the
North from the gulf.

 I had a BOG before and used a beads that had a Q of 1 or 2.
 so if I could get 20 it would be better.

The main selling point of Beverages is that it is wide band, you
definitely _do_not_ want any high-Q (i.e. low bandwidth) constructs.

Yes but when it is short you lose directivity.
Mikek

 

[amdx]

On 8/23/2019 11:17 AM, Simon S Aysdie wrote:

On Tuesday, August 20, 2019 at 8:00:20 PM UTC-7, amdx wrote:
On 8/20/2019 12:47 PM, amdx wrote:
On 8/20/2019 11:11 AM, Tim Williams wrote:
"amdx" <nojunk@knology.net> wrote in message

I had a BOG before and used a bedds...

I still don't know what you're writing. It ain't English...

Well, "bog" aside. But that means something different in English
English.
;-)

I'll try to get a good nights sleep tonight!
BOG = Beverage On Ground

Sun streaking cold
An old man wandering lonely
Taking time
The only way he knows
Leg hurting bad
As he bends to pick a dog-end
He goes down to the BOG
And warms his feet
Feeling alone
The army's up the road
Salvation a la mode and
A cup of tea

BOG = Beverage On Ground

A beverage antenna is generally described as a 1 wavelength antenna,
(more or less)
Mike

 

[Simon S Aysdie]

On Tuesday, August 20, 2019 at 8:00:20 PM UTC-7, amdx wrote:

On 8/20/2019 12:47 PM, amdx wrote:
On 8/20/2019 11:11 AM, Tim Williams wrote:
"amdx" <nojunk@knology.net> wrote in message

I had a BOG before and used a bedds...

I still don't know what you're writing. It ain't English...

Well, "bog" aside. But that means something different in English
English.
;-)

I'll try to get a good nights sleep tonight!
BOG = Beverage On Ground

Sun streaking cold
An old man wandering lonely
Taking time
The only way he knows
Leg hurting bad
As he bends to pick a dog-end
He goes down to the BOG
And warms his feet
Feeling alone
The army's up the road
Salvation a la mode and
A cup of tea