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?
Mikek

*It had a vacuum variable mounted on it, I had it in the garage and my
young son moved it and broke the glass on the vacuum variable, it was a
sad day for me.

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"!

--

Rick

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 2:36 PM, rickman wrote:
On 11/10/2015 12:40 PM, amdx wrote:
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!


Where did you get 96% efficient?

From the site below.
"The efficiency of a magnetic loop antenna is typically calculated as
(Smith, 2006);

efficiency=Rr/(Rr+Rhf2)

Rr=radiation resistance (ohms)

Rhf2=RF losses from combined skin effect and proximity effect (ohms)

This term is not adjusted for the effects of ground or nearby objects."


This builder has a different design.

http://gridtoys.com/glen/loop/loop3.html

You'll enjoy this line on his page.

"*Aluminum works well in magnetic loop antennas. Yes, pure copper is a
little better, but in multiple conductor magnetic loop antennas, there
may be difficulty getting a copper loop to support its own weight.
Structurally, aluminum is a lot better. Just make the conductors bigger."

Mikek

On 11/11/2015 6:59 AM, amdx wrote:
On 11/10/2015 2:36 PM, rickman wrote:
On 11/10/2015 12:40 PM, amdx wrote:
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!


Where did you get 96% efficient?

PFA It is an example of an efficient loop. Work with a less efficient
loop and the sliver still makes only a small difference, less than the
raw 5% difference in conductivity.


From the site below.
"The efficiency of a magnetic loop antenna is typically calculated as
(Smith, 2006);

efficiency=Rr/(Rr+Rhf2)

Rr=radiation resistance (ohms)

Rhf2=RF losses from combined skin effect and proximity effect (ohms)

This term is not adjusted for the effects of ground or nearby objects."

Your point?

BTW, Rhf2 I believe is intended to be the resistive losses after
considering the skin and proximity effects. As you can see, a 5%
difference in Rhf2 will be less than 5% in the efficiency and depending
on the numbers, much less.

If you are working at very low efficiencies, then yes, a 5% difference
in Rhf2 will result in a noticeable difference in efficiency, but this
would be improved much more by using a good design rather than a poor
one. Silver plating a crap antenna will still give you a crap antenna.


This builder has a different design.

http://gridtoys.com/glen/loop/loop3.html

You'll enjoy this line on his page.

"*Aluminum works well in magnetic loop antennas. Yes, pure copper is a
little better, but in multiple conductor magnetic loop antennas, there
may be difficulty getting a copper loop to support its own weight.
Structurally, aluminum is a lot better. Just make the conductors bigger."

Not sure what he is talking about. He seems to have screwed up the
formulas calcuating the skin effect. I can't reconcile his math.

--

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 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 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

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