On Tue, 10 Nov 2015 09:10:00 -0600, amdx wrote:

My magloop nightmare come true:
http://www.mixw.co.uk/MagLoop/magloopF.htm

I don't get your point here.

1. It's not a fractal.
2. It's more like art than science.
3. It's a variation on my dryer vent hose antenna (tune by pounding).
4. It maximizes most of the worst characteristics of a loop, such as
high length to surface area = low Q, small capture area, and optimized
for low VSWR.
5. If you're worried about temperature drift, the lack of rigidity
should make it drift even more.

Build one, monitor your dreams.

My ego is too inflated to fit into the loop. I'll stick with the
traditional colander on the head arrangement:
https://www.google.com/search?q=colander+on+head&tbm=isch

Jeff, I don't like the parallel sections,
seems like it could be made more complicated
using x, y, and z right angles. Nap on that! :-)
Mikek

Sorry, but everything I've built that involves a 4th dimension has
dissapeared when I applied power. The fields cancel and the entire
antenna is sucked into the resultant vortex.

Argh... I'm late again.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 11/10/2015 9:30 AM, rickman wrote:
On 11/10/2015 9:12 AM, amdx wrote:
On 11/10/2015 1:41 AM, rickman wrote:
On 11/9/2015 12:08 PM, amdx wrote:


The silver is simply optimization. If you can make your coil wire 5%
bigger, you should have already done that. Then if you want to
optimized
1 + 0.05, silver plate it.

Why can't you make the wire 5% bigger again? Where exactly is the cost?

You can.
I don't think ultimate optimizing is for you.
Just make your coil with as much surface area as room will allow.
Then know it could have just a tiny bit less loss if you had the silver.
That tiny bit of loss will not be noticed in use, except for that little
nagging thought...

I once had a 6 or 7 turn loop made with 1/4" copper tubing*, Q was about
800 at 1MHz. I could have made it with 1/2" tubing, probably would have
had higher Q.
I guess the limits are money and how you want to limit physical size and
maximum inductance you can use. Did I miss any?

People seem to go nuts with ideas that you need to optimize every little
thing without any evidence to show the significance of the impact on
performance. Your example is perfect. Increasing the copper tube from
1/4 inch to even just 3/8 inch would more than make up for silver
plating and not really cost that much more. There are guys who talk
about using single piece, 3 inch copper tube bent into a loop to avoid
having solder joints when using straight pieces even though those solder
joints will be about the same resistance as a quarter inch of the tube
or a microscopic increase in the resistance. Then they conveniently
forget about the resistance of the clamp connection to the vacuum
variable capacitor swamping out the solder joint resistance even more.

It makes me want to scream, "Enough of the maddness"!


You want to see guys reaching for lowest losses, highest Q, follow a
crystal radio group.
Some there claim Q's of 2000, (I believe them) Using 2 and 3 parallel
pieces of 660/46 Litz wire. AMBCB.
The 2000Q thread; http://tinyurl.com/q2hc6ga

More info, or a way to get to page two and three;

"Meanwhile, you can do the following search on Google:
site:www.midnightscience.com/rapntap/ 2000Q
If the main blue link doesn't work, then go down to the green link one
line below, and the little drop down menu at the right, and select
"cached" which will show you Google's cached copy of the page."

I didn't know that Google trick!


Recently a ferrite material out of China has made inductors hitting
1300 Q's easy. AMBCB
http://theradioboard.com/rb/viewtopic.php?f=5&t=6259
Also rods of the same material.

Mikek

On 11/10/2015 12:40 PM, amdx wrote:
On 11/10/2015 9:30 AM, rickman wrote:
On 11/10/2015 9:12 AM, amdx wrote:
On 11/10/2015 1:41 AM, rickman wrote:
On 11/9/2015 12:08 PM, amdx wrote:


The silver is simply optimization. If you can make your coil wire 5%
bigger, you should have already done that. Then if you want to
optimized
1 + 0.05, silver plate it.

Why can't you make the wire 5% bigger again? Where exactly is the
cost?

You can.
I don't think ultimate optimizing is for you.
Just make your coil with as much surface area as room will allow.
Then know it could have just a tiny bit less loss if you had the silver.
That tiny bit of loss will not be noticed in use, except for that little
nagging thought...

I once had a 6 or 7 turn loop made with 1/4" copper tubing*, Q was about
800 at 1MHz. I could have made it with 1/2" tubing, probably would have
had higher Q.
I guess the limits are money and how you want to limit physical size and
maximum inductance you can use. Did I miss any?

People seem to go nuts with ideas that you need to optimize every little
thing without any evidence to show the significance of the impact on
performance. Your example is perfect. Increasing the copper tube from
1/4 inch to even just 3/8 inch would more than make up for silver
plating and not really cost that much more. There are guys who talk
about using single piece, 3 inch copper tube bent into a loop to avoid
having solder joints when using straight pieces even though those solder
joints will be about the same resistance as a quarter inch of the tube
or a microscopic increase in the resistance. Then they conveniently
forget about the resistance of the clamp connection to the vacuum
variable capacitor swamping out the solder joint resistance even more.

It makes me want to scream, "Enough of the maddness"!


You want to see guys reaching for lowest losses, highest Q, follow a
crystal radio group.
Some there claim Q's of 2000, (I believe them) Using 2 and 3 parallel
pieces of 660/46 Litz wire. AMBCB.
The 2000Q thread; http://tinyurl.com/q2hc6ga

More info, or a way to get to page two and three;

"Meanwhile, you can do the following search on Google:
site:www.midnightscience.com/rapntap/ 2000Q
If the main blue link doesn't work, then go down to the green link one
line below, and the little drop down menu at the right, and select
"cached" which will show you Google's cached copy of the page."

I didn't know that Google trick!


Recently a ferrite material out of China has made inductors hitting
1300 Q's easy. AMBCB
http://theradioboard.com/rb/viewtopic.php?f=5&t=6259
Also rods of the same material.

Crystal radio is a bit different. There your power source is the air
waves, so a higher Q makes a difference. When transmitting with a 96%
efficiency, using silver plating will only improve this to 96.2% at
very best. Not really useful and likely not measurable. Better to deal
with the significant losses like the extremely bad connection between
the vacuum variable cap and the loop. Straps???!!! Get real!

--

Rick

On 11/10/2015 12:17 PM, Jeff Liebermann wrote:
On Tue, 10 Nov 2015 09:10:00 -0600, amdx wrote:

My magloop nightmare come true:
http://www.mixw.co.uk/MagLoop/magloopF.htm

I don't get your point here.

1. It's not a fractal.
2. It's more like art than science.
3. It's a variation on my dryer vent hose antenna (tune by pounding).
4. It maximizes most of the worst characteristics of a loop, such as
high length to surface area = low Q, small capture area, and optimized
for low VSWR.
5. If you're worried about temperature drift, the lack of rigidity
should make it drift even more.

But you don't really know the details of how it works, so you don't know
how well it can work other than by building it and testing. I haven't
seen any reports that can be considered rigorous, but there is plenty of
enthusiasm by the users. They think these antennas work well.


Build one, monitor your dreams.

My ego is too inflated to fit into the loop. I'll stick with the
traditional colander on the head arrangement:
https://www.google.com/search?q=colander+on+head&tbm=isch

Are you making fun of religion now?


Jeff, I don't like the parallel sections,
seems like it could be made more complicated
using x, y, and z right angles. Nap on that! :-)
Mikek

Sorry, but everything I've built that involves a 4th dimension has
dissapeared when I applied power. The fields cancel and the entire
antenna is sucked into the resultant vortex.

Argh... I'm late again.

Someday you'll be late for the last time and everyone will call you "late".

--

Rick

On 11/10/2015 11:40 AM, amdx wrote:
On 11/10/2015 9:30 AM, rickman wrote:
On 11/10/2015 9:12 AM, amdx wrote:
On 11/10/2015 1:41 AM, rickman wrote:
On 11/9/2015 12:08 PM, amdx wrote:


The silver is simply optimization. If you can make your coil wire 5%
bigger, you should have already done that. Then if you want to
optimized
1 + 0.05, silver plate it.

Why can't you make the wire 5% bigger again? Where exactly is the
cost?

You can.
I don't think ultimate optimizing is for you.
Just make your coil with as much surface area as room will allow.
Then know it could have just a tiny bit less loss if you had the silver.
That tiny bit of loss will not be noticed in use, except for that little
nagging thought...

I once had a 6 or 7 turn loop made with 1/4" copper tubing*, Q was about
800 at 1MHz. I could have made it with 1/2" tubing, probably would have
had higher Q.
I guess the limits are money and how you want to limit physical size and
maximum inductance you can use. Did I miss any?

People seem to go nuts with ideas that you need to optimize every little
thing without any evidence to show the significance of the impact on
performance. Your example is perfect. Increasing the copper tube from
1/4 inch to even just 3/8 inch would more than make up for silver
plating and not really cost that much more. There are guys who talk
about using single piece, 3 inch copper tube bent into a loop to avoid
having solder joints when using straight pieces even though those solder
joints will be about the same resistance as a quarter inch of the tube
or a microscopic increase in the resistance. Then they conveniently
forget about the resistance of the clamp connection to the vacuum
variable capacitor swamping out the solder joint resistance even more.

It makes me want to scream, "Enough of the maddness"!


You want to see guys reaching for lowest losses, highest Q, follow a
crystal radio group.
Some there claim Q's of 2000, (I believe them) Using 2 and 3 parallel
pieces of 660/46 Litz wire. AMBCB.
The 2000Q thread; http://tinyurl.com/q2hc6ga

More info, or a way to get to page two and three;

"Meanwhile, you can do the following search on Google:
site:www.midnightscience.com/rapntap/ 2000Q
If the main blue link doesn't work, then go down to the green link one
line below, and the little drop down menu at the right, and select
"cached" which will show you Google's cached copy of the page."

I didn't know that Google trick!


Recently a ferrite material out of China has made inductors hitting
1300 Q's easy. AMBCB
http://theradioboard.com/rb/viewtopic.php?f=5&t=6259
Also rods of the same material.

Mikek

I'm curious about the 2000 Q restricting bandwidth. At 1MHz, the
bandwidth would be only 500Hz. Does that affect the quality of the
audio? That is, does it sound very bass-y?

On Tue, 10 Nov 2015 16:09:51 -0500, rickman wrote:

But you don't really know the details of how it works, so you don't know
how well it can work other than by building it and testing.

I can get a clue on how well it works from an NEC2 model. However,
this loop is easy. Remember your complaints about the relative merits
of a circular loop, octagonal loop, square, and triangular loop? Well,
this contrivance is a good example of a very shrunken loop, where the
area enclosed by the loop has been minimized.

Anyway, I'm a big fan of building something just to see what happens.
It's part of "Learn by Destroying".

I haven't
seen any reports that can be considered rigorous, but there is plenty of
enthusiasm by the users. They think these antennas work well.

Yep. I also read the reviews on various products and usually find a
few fanatics that will defend inferior junk to the death. It happens.
However, I'm not talking about "these" antennas as in all types of
loop antennas. I'm talking about this particular loop:
http://www.mixw.co.uk/MagLoop/magloopF.htm

My ego is too inflated to fit into the loop. I'll stick with the
traditional colander on the head arrangement:
https://www.google.com/search?q=colander+on+head&tbm=isch

Are you making fun of religion now?

I'm Jewish and occasionally wear a yarmulke (keepah or skull cap)
which entitles me to some liberties in their design and operation.
Full disclosu Mine is not lined with tin foil.

Argh... I'm late again.

Someday you'll be late for the last time and everyone will call you "late".

Actually, I try to always be on time or a little early. In this case,
it was for a ritual morning exercise trudge through the local state
park. We usually have a small group that I didn't want to keep
waiting.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Tue, 10 Nov 2015 11:40:43 -0600, amdx wrote:

You want to see guys reaching for lowest losses, highest Q, follow a
crystal radio group.
Some there claim Q's of 2000, (I believe them) Using 2 and 3 parallel
pieces of 660/46 Litz wire. AMBCB.
The 2000Q thread; http://tinyurl.com/q2hc6ga

That's the unloaded Q measured in an HP4342A Q meter. Putting a load
across the coil will drop the Q considerably.

The equivalent parallel resistor across a perfect 120uHy inductor and
resonating capacitor a

R = Q * 2*Pi*f*L
R = 2000 * 2 * 3.14 * 1*10^6 * 120*10^-6
R = 1.5Meg

So, all it would take is a 1.5Meg load across the parallel coil and
capacitor, and the Q would get cut in half. That doesn't sound very
practical.

I used an HP4342A at a former employer. Nice machine but really
unstable for high-Q measurements. I'm not surprised that he had to
leave it running for a while to stabilize:
http://www.radiomuseum.org/r/hewlett_pa_q_meter_4342a4342.html
$300 to $500 on eBay. Ouch.

Drivel: The MFJ-259a is now fixed. It was the usual blown diodes,
along with cleaning up the mess left by the leaky batteries.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 11/10/2015 5:55 PM, John S wrote:
On 11/10/2015 11:40 AM, amdx wrote:

Recently a ferrite material out of China has made inductors hitting
1300 Q's easy. AMBCB
http://theradioboard.com/rb/viewtopic.php?f=5&t=6259
Also rods of the same material.

Mikek

I'm curious about the 2000 Q restricting bandwidth. At 1MHz, the
bandwidth would be only 500Hz. Does that affect the quality of the
audio? That is, does it sound very bass-y?

At 60 kHz the bandwidth would be 30 Hz, perfect! Great SNR improvement.

--

Rick

On 11/10/2015 7:37 PM, Jeff Liebermann wrote:
On Tue, 10 Nov 2015 16:09:51 -0500, rickman wrote:

But you don't really know the details of how it works, so you don't know
how well it can work other than by building it and testing.

I can get a clue on how well it works from an NEC2 model. However,
this loop is easy. Remember your complaints about the relative merits
of a circular loop, octagonal loop, square, and triangular loop? Well,
this contrivance is a good example of a very shrunken loop, where the
area enclosed by the loop has been minimized.

That is an assumption since you are analyzing it as a simple, circular
loop which it is not. NEC2 may or may not be adequate to model it.
Someone posted that they get significantly different results from two
different simulators under some conditions.


Anyway, I'm a big fan of building something just to see what happens.
It's part of "Learn by Destroying".

I haven't
seen any reports that can be considered rigorous, but there is plenty of
enthusiasm by the users. They think these antennas work well.

Yep. I also read the reviews on various products and usually find a
few fanatics that will defend inferior junk to the death. It happens.
However, I'm not talking about "these" antennas as in all types of
loop antennas. I'm talking about this particular loop:
http://www.mixw.co.uk/MagLoop/magloopF.htm

My ego is too inflated to fit into the loop. I'll stick with the
traditional colander on the head arrangement:
https://www.google.com/search?q=colander+on+head&tbm=isch

Are you making fun of religion now?

I'm Jewish and occasionally wear a yarmulke (keepah or skull cap)
which entitles me to some liberties in their design and operation.
Full disclosu Mine is not lined with tin foil.

I'm referring to the Pastafarians of which I am a member.


Argh... I'm late again.

Someday you'll be late for the last time and everyone will call you "late".

Actually, I try to always be on time or a little early. In this case,
it was for a ritual morning exercise trudge through the local state
park. We usually have a small group that I didn't want to keep
waiting.

I mean "late as in *the late* Dentarthurdent".

--

Rick

On 11/10/2015 4:55 PM, John S wrote:
On 11/10/2015 11:40 AM, amdx wrote:
On 11/10/2015 9:30 AM, rickman wrote:
On 11/10/2015 9:12 AM, amdx wrote:
On 11/10/2015 1:41 AM, rickman wrote:
On 11/9/2015 12:08 PM, amdx wrote:


The silver is simply optimization. If you can make your coil
wire 5%
bigger, you should have already done that. Then if you want to
optimized
1 + 0.05, silver plate it.

Why can't you make the wire 5% bigger again? Where exactly is the
cost?

You can.
I don't think ultimate optimizing is for you.
Just make your coil with as much surface area as room will allow.
Then know it could have just a tiny bit less loss if you had the
silver.
That tiny bit of loss will not be noticed in use, except for that
little
nagging thought...

I once had a 6 or 7 turn loop made with 1/4" copper tubing*, Q was
about
800 at 1MHz. I could have made it with 1/2" tubing, probably would have
had higher Q.
I guess the limits are money and how you want to limit physical size
and
maximum inductance you can use. Did I miss any?

People seem to go nuts with ideas that you need to optimize every little
thing without any evidence to show the significance of the impact on
performance. Your example is perfect. Increasing the copper tube from
1/4 inch to even just 3/8 inch would more than make up for silver
plating and not really cost that much more. There are guys who talk
about using single piece, 3 inch copper tube bent into a loop to avoid
having solder joints when using straight pieces even though those solder
joints will be about the same resistance as a quarter inch of the tube
or a microscopic increase in the resistance. Then they conveniently
forget about the resistance of the clamp connection to the vacuum
variable capacitor swamping out the solder joint resistance even more.

It makes me want to scream, "Enough of the maddness"!


You want to see guys reaching for lowest losses, highest Q, follow a
crystal radio group.
Some there claim Q's of 2000, (I believe them) Using 2 and 3 parallel
pieces of 660/46 Litz wire. AMBCB.
The 2000Q thread; http://tinyurl.com/q2hc6ga

More info, or a way to get to page two and three;

"Meanwhile, you can do the following search on Google:
site:www.midnightscience.com/rapntap/ 2000Q
If the main blue link doesn't work, then go down to the green link one
line below, and the little drop down menu at the right, and select
"cached" which will show you Google's cached copy of the page."

I didn't know that Google trick!


Recently a ferrite material out of China has made inductors hitting
1300 Q's easy. AMBCB
http://theradioboard.com/rb/viewtopic.php?f=5&t=6259
Also rods of the same material.

Mikek

I'm curious about the 2000 Q restricting bandwidth. At 1MHz, the
bandwidth would be only 500Hz. Does that affect the quality of the
audio? That is, does it sound very bass-y?

Jeff explained the loading, but I'll add, the rest of the circuitry to
extract the audio signal and drive the headphones to create sound drops
the Q. It can be as bad as a 2000 ohm headphone or as good as a
transformer with very high input impedance, over 1.5 Megaohms according
to Ben Tongue.

http://www.bentongue.com/xtalset/5hpXform/5hpXform.html

All 29 of his crystal radio research papers are here.

http://www.bentongue.com/xtalset/xtalset.html

Tremendous resource for Crystal Radio devotees.
Mikek