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Simon S Aysdie
Guest

Tue Feb 05, 2019 2:45 am   



On Monday, February 4, 2019 at 3:13:34 PM UTC-8, Clifford Heath wrote:
Quote:
On 5/2/19 9:28 am, John Larkin wrote:

https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.

Have you played with conical-wound broadband inductors? There are some
amazing examples. E.g. <https://www.coilcraft.com/conicals/index.cfm


Piconics was the first conical inductor company. Gowanda also sells them. AVX had some too, last I checked. Conicals are fragile and Production always hates them.

One has to be careful in interpreting current rating across vendors. John's Tee says 0.5 A, but no conditions accompany it. The CCI BCL-652JL is 6.5 uH and 650 mA causes a 40°C rise from 25°C. I'm not sure how the temperature delta is measured. It seems like a thermocouple would draw heat away from the thing it was measuring. For a small thing, maybe that matters..

John Larkin
Guest

Tue Feb 05, 2019 2:45 am   



On Tue, 5 Feb 2019 11:43:26 +1100, Clifford Heath <no.spam_at_please.net>
wrote:

Quote:
On 5/2/19 11:24 am, John Larkin wrote:
On Tue, 5 Feb 2019 10:13:26 +1100, Clifford Heath <no.spam_at_please.net
wrote:

On 5/2/19 9:28 am, John Larkin wrote:

https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.

Have you played with conical-wound broadband inductors? There are some
amazing examples. E.g. <https://www.coilcraft.com/conicals/index.cfm

Clifford Heath

Yes, we'll probably use them in production. The bias tees are for
testing parts first.

It looks like the Piconics patents ran out, so other people are making
conicals. Prices have dropped roughly 4:1.

These are cool, ferrite filled like the conicals but higher current.

https://www.coilcraft.com/4310lc.cfm

I don't understand how they can have "Flat bandwidth with high impedance
to 6 GHz" but an SRF of 235MHz. Surely if they turn capacitive above
235MHz they're still capacitive at 6GHz?

Clifford Heath.


They have impedance:frequency curves.

Sure they get capacitive at very high frequencies; all inductors do
that. But the impedance is still high.

Capacitors are still useful above their SRF too. A 47 uF ceramic cap
is going to have a pretty low SRF!


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

John Larkin
Guest

Tue Feb 05, 2019 5:45 am   



On Mon, 4 Feb 2019 17:01:13 -0800 (PST), George Herold
<gherold_at_teachspin.com> wrote:

Quote:
On Monday, February 4, 2019 at 7:26:09 PM UTC-5, John Larkin wrote:
On Mon, 4 Feb 2019 18:27:24 -0500, bitrex <user_at_example.net> wrote:

On 02/04/2019 05:28 PM, John Larkin wrote:

https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.



Capacitor and two pieces of wire?

https://www.dropbox.com/s/hz4wj3fltsetqqj/Amazon_Tee.jpg?dl=0
The connector ground pads on the pcb look de-soldered?
Don't I want my pcb grounded right at the in/outputs?
(that's what I always do.)

George H.


The pcb layout was obviously for edge-launch SMAs, but maybe they got
the flange parts cheap.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

Gerhard Hoffmann
Guest

Tue Feb 05, 2019 5:45 am   



Am 05.02.19 um 05:00 schrieb John Larkin:
Quote:
On Tue, 5 Feb 2019 02:10:49 +0100, Gerhard Hoffmann

For upto 10 GHz, 100nF 0402 is OK as the capacitor, esp. if you only
want nice optical eyes.

We use the sideways caps for fast stuff, like 0306 instead of 0603.
Much better at speed.

I have some of them here, but never really used.


Also interesting are XY capacitors with contacts also in the middle of
the long side. Available vom Johanson and some others.
They are designed with via placement to VCC and GND plane in mind.
The flux from the vias cancels.

Quote:
This here is a PicoSecondPulseLabs 5828-108 amplifier. 15 GHz / 22ps tr.


https://www.flickr.com/photos/137684711_at_N07/33112324418/in/dateposted-public/

What did that cost?


Don't remember.
Bought them on ebay from some guy in Switzerland.

Quote:
and the notes I made when I opened it some years ago is to the right.
(and even further right some of Gerhard's adventures)


Fog on hills. Looks a bit like San Francisco.


THAT kind of fog in SF would be scaring. Maybe when St.Andreas wakes up.
That's a hi temperature field in Iceland. They skimp on warning signs.
But when there is one, you better respect it. If you walk there,
you might break into a hole with hot sulfuric slime around your knees.

Oh, and it stinks. Mother Earth, the Queen of farts.

regards,
Gerhard

John Larkin
Guest

Tue Feb 05, 2019 5:45 am   



On Tue, 5 Feb 2019 02:10:49 +0100, Gerhard Hoffmann
<ghf_at_hoffmann-hochfrequenz.de> wrote:

Quote:
Am 05.02.19 um 00:13 schrieb Clifford Heath:
On 5/2/19 9:28 am, John Larkin wrote:

https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1


We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.

Have you played with conical-wound broadband inductors? There are some
amazing examples. E.g. <https://www.coilcraft.com/conicals/index.cfm

A long time ago, we tried them for the DFB lasers in our fiberoptic
transceivers. Worked very good, but at $35 a pop impossible for
production. Thanks goddess, that Piconics patent has exspired now.

I once told the MCL sales guy that they might sell one for each
ERA-8 if the price was right. He was all ears. :-)

One of my colleagues put some RF ferrite into a mortar, added some
epoxy and formed a conical core himself. That looked ugly but
performed quite well. Cost a lot more than Piconics and was unfit
for production. But educating. :-)

For upto 10 GHz, 100nF 0402 is OK as the capacitor, esp. if you only
want nice optical eyes.


We use the sideways caps for fast stuff, like 0306 instead of 0603.
Much better at speed.






Quote:

The choke is harder; it can be made from really cheap parts but
it takes a day at the VNA, some creative soldering and the inductor /
ferrite / resistor kit.

This here is a PicoSecondPulseLabs 5828-108 amplifier. 15 GHz / 22ps tr.


https://www.flickr.com/photos/137684711_at_N07/33112324418/in/dateposted-public/


What did that cost?

Quote:


and the notes I made when I opened it some years ago is to the right.
(and even further right some of Gerhard's adventures)


Fog on hills. Looks a bit like San Francisco.

https://www.dropbox.com/s/b441bf7y5rfj1kh/Fog_p2.JPG?dl=0



Quote:
Data sheet of the amplifier:
https://www.oequest.com/getDatasheet/id/2116-2116.pdf


Input is to the left, output right and on the underside there
is a CCS made from LM3xx. There is also some ferrite rubber
glued to the upper lid to dampen the box modes.

They use a monolayer capacitor that is about as wide as the
microstrip. The ustrip has just a narrow cut and the other side
of the monolayer cap is contacted with a piece of wide Cu foil.
Parallel to the monolayer C there are 2 additional 0402 caps,
soldered on top.


On the output side, there is a series RC to gnd after the first
coil to dampen some resonance. Don't use too much inductance to
push down the lower frequency limit. It stores energy and if
you short Vcc that may kill the amplifier chip / DUT.

cheers,
Gerhard


Here's an ancient ebay PSPL bias tee:

https://www.dropbox.com/s/vvcmflsu5e5eju6/PSPL_tee.zip?dl=0

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

Jan Panteltje
Guest

Tue Feb 05, 2019 10:45 am   



here is the inside of my home made one for 1.5 GHz:
http://panteltje.com/pub/GPS_antenna_T_power_section_IMG_3790.GIF

The little square thing on the left is a E4000 RTL-SDR tuner,
the mouse like thing is a GPS mouse.

Basically a SMD capacitator and indiductor on a peeseebee.

AND mine has a LM317 build in voltage stabilizer!!!!!
All from the junk box at zero dullers
:-0

Tom Gardner
Guest

Tue Feb 05, 2019 10:45 am   



On 05/02/19 04:38, Gerhard Hoffmann wrote:
Quote:
That's a hi temperature field in Iceland. They skimp on warning signs.
But when there is one, you better respect it. If you walk there,
you might break into a hole with hot sulfuric slime around your knees.


They are getting "better", e.g. there are now safety rails
at Gullfoss waterfall.
https://i1.wp.com/www.followmeaway.com/wp-content/uploads/2018/01/gullfoss-waterfall-iceland-closed-viewpoint.jpg

When I last went they took the attitude that if you couldn't
work out that spray+rocks+chasm means you might fall and die,
then that would merely improve the species.


> Oh, and it stinks. Mother Earth, the Queen of farts.

Isn't H2S wonderful.


Guest

Tue Feb 05, 2019 10:45 am   



John Larkin wrote
Quote:
https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.


Insane high pricing,
here is the inside of my home made one for 1.5 GHz:
http://panteltje.com/pub/GPS_antenna_T_power_section_IMG_3790.GIF

The little square thing on the left is a E4000 RTL-SDR tuner,
the mouse like thing is a GPS mouse.

Basically a SMD capacitator and indiductor on a peeseebee.


Guest

Tue Feb 05, 2019 2:45 pm   



On Tuesday, February 5, 2019 at 7:48:43 PM UTC+11, Tom Gardner wrote:
Quote:
On 05/02/19 04:38, Gerhard Hoffmann wrote:
That's a hi temperature field in Iceland. They skimp on warning signs.
But when there is one, you better respect it. If you walk there,
you might break into a hole with hot sulfuric slime around your knees.

They are getting "better", e.g. there are now safety rails
at Gullfoss waterfall.
https://i1.wp.com/www.followmeaway.com/wp-content/uploads/2018/01/gullfoss-waterfall-iceland-closed-viewpoint.jpg

When I last went they took the attitude that if you couldn't
work out that spray+rocks+chasm means you might fall and die,
then that would merely improve the species.

Oh, and it stinks. Mother Earth, the Queen of farts.

Isn't H2S wonderful.


Except that farts are supposed to stink of skatole

https://en.wikipedia.org/wiki/Skatole

otherwise 4-Methyl-2,3-benzopyrrole,

A bit of googling suggests that the actual stink in Iceland is mainly sulphur dioxide, which is unpleasant enough, but rather different from either H2S (rotten egg gas) or skatole. SO2 dissolves in water to give sulphurous acid, which oxidises in contact with air to sulphuric acid which fits the reference to "hot sulfuric slime".

H2S is remarkably toxic - on par with carbon monoxide - and it saturates the olefactory system above 150ppm, which means you may stop smelling it before it hits the lethal level of 500ppm or higher.

One of the party boats on Sydney screwed up its sewage tank management, and killed a passenger recently. The autopsy isn't in yet, so we can't be sure if it was H2S that did her in, but it is the prime suspect.

--
Bill Sloman, Sydney

Tim Williams
Guest

Tue Feb 05, 2019 3:45 pm   



"Clifford Heath" <no.spam_at_please.net> wrote in message
news:R_46E.269058$0z4.266603_at_fx03.iad...
Quote:
These are cool, ferrite filled like the conicals but higher current.

https://www.coilcraft.com/4310lc.cfm

I don't understand how they can have "Flat bandwidth with high impedance
to 6 GHz" but an SRF of 235MHz. Surely if they turn capacitive above
235MHz they're still capacitive at 6GHz?


Well, think about it. If there's more than 1/4 wave of wire there, then it
must fall over at some frequency of interest, and the fields will be very
different along the coil, not just a simple gradient. The first resonance
is good, it's a parallel resonance, high Z. The second resonance, and every
other one thereafter, is bad. The only way to keep impedance high, is to
absorb those resonances in a loss element.

If you use a tapped coil, you can add taps at strategic points, to dampen
across the antinodes of each resonance of interest.

If you use a solenoid or toroidial coil, a lossy material inside -- and
outside, mind, because the fields are external at these frequencies -- can
dampen that.

This keeps impedance flat, and a flat impedance must necessarily be lossy.
The loss sink is the core material.

Note that you can't simply taper the coil (coreless), or do a progressive
wound solenoid or whatever. There _must_ be a loss sink somewhere,
otherwise you're just making resonators in different shapes!

If you use a conical coil, you're really making a conical spiral antenna,
which has circular polarization and good directivity. Direct that energy
into a wad of ferrite, and it's gone forever -- rather than reflecting and
causing peaks and dips.

I don't think there's really anything very special that you can do with a
conical. The self-similar shape may make it easier to get a flat impedance,
but that impedance still isn't going to be very high, on account of how much
of the spiral is inducting versus how much is absorbing.

Tim

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

John Larkin
Guest

Tue Feb 05, 2019 4:45 pm   



On Tue, 5 Feb 2019 08:18:56 -0600, "Tim Williams"
<tiwill_at_seventransistorlabs.com> wrote:

Quote:
"Clifford Heath" <no.spam_at_please.net> wrote in message
news:R_46E.269058$0z4.266603_at_fx03.iad...
These are cool, ferrite filled like the conicals but higher current.

https://www.coilcraft.com/4310lc.cfm

I don't understand how they can have "Flat bandwidth with high impedance
to 6 GHz" but an SRF of 235MHz. Surely if they turn capacitive above
235MHz they're still capacitive at 6GHz?

Well, think about it. If there's more than 1/4 wave of wire there, then it
must fall over at some frequency of interest, and the fields will be very
different along the coil, not just a simple gradient. The first resonance
is good, it's a parallel resonance, high Z. The second resonance, and every
other one thereafter, is bad. The only way to keep impedance high, is to
absorb those resonances in a loss element.

If you use a tapped coil, you can add taps at strategic points, to dampen
across the antinodes of each resonance of interest.

If you use a solenoid or toroidial coil, a lossy material inside -- and
outside, mind, because the fields are external at these frequencies -- can
dampen that.

This keeps impedance flat, and a flat impedance must necessarily be lossy.
The loss sink is the core material.

Note that you can't simply taper the coil (coreless), or do a progressive
wound solenoid or whatever. There _must_ be a loss sink somewhere,
otherwise you're just making resonators in different shapes!

If you use a conical coil, you're really making a conical spiral antenna,
which has circular polarization and good directivity. Direct that energy
into a wad of ferrite, and it's gone forever -- rather than reflecting and
causing peaks and dips.

I don't think there's really anything very special that you can do with a
conical. The self-similar shape may make it easier to get a flat impedance,
but that impedance still isn't going to be very high, on account of how much
of the spiral is inducting versus how much is absorbing.

Tim


A conical inductor is the distributed equivalent of the old trick of
putting progressively larger damped inductors in series.

Take a look at these impedance curves:

https://www.coilcraft.com/pdfs/bcl.pdf


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

Tom Gardner
Guest

Tue Feb 05, 2019 5:45 pm   



On 05/02/19 13:20, bill.sloman_at_ieee.org wrote:
Quote:
On Tuesday, February 5, 2019 at 7:48:43 PM UTC+11, Tom Gardner wrote:
On 05/02/19 04:38, Gerhard Hoffmann wrote:
That's a hi temperature field in Iceland. They skimp on warning signs.
But when there is one, you better respect it. If you walk there, you
might break into a hole with hot sulfuric slime around your knees.

They are getting "better", e.g. there are now safety rails at Gullfoss
waterfall.
https://i1.wp.com/www.followmeaway.com/wp-content/uploads/2018/01/gullfoss-waterfall-iceland-closed-viewpoint.jpg



When I last went they took the attitude that if you couldn't
work out that spray+rocks+chasm means you might fall and die, then that
would merely improve the species.

Oh, and it stinks. Mother Earth, the Queen of farts.

Isn't H2S wonderful.

Except that farts are supposed to stink of skatole

https://en.wikipedia.org/wiki/Skatole

otherwise 4-Methyl-2,3-benzopyrrole,

A bit of googling suggests that the actual stink in Iceland is mainly sulphur
dioxide, which is unpleasant enough, but rather different from either H2S
(rotten egg gas) or skatole. SO2 dissolves in water to give sulphurous acid,
which oxidises in contact with air to sulphuric acid which fits the reference
to "hot sulfuric slime".


When I was there, the "rotten eggs" smell of H2S was
the one I noticed.

I know it was H2S since I made it in the kitchen when
I was a kid. My father brought home iron (II) sulphate (?)
and conc HCl in his coat pocket :)


Quote:
H2S is remarkably toxic - on par with carbon monoxide - and it saturates the
olefactory system above 150ppm, which means you may stop smelling it before
it hits the lethal level of 500ppm or higher.


Only found out about the toxicity much later!


Quote:
One of the party boats on Sydney screwed up its sewage tank management, and
killed a passenger recently. The autopsy isn't in yet, so we can't be sure if
it was H2S that did her in, but it is the prime suspect.


I always assumed that the stench made people "be somewhere
else" long before the toxicity would be a major problem.
But if they are dead drunk then all bets would be off.

Jeroen Belleman
Guest

Tue Feb 05, 2019 5:45 pm   



John Larkin wrote:
Quote:
On Tue, 5 Feb 2019 08:18:56 -0600, "Tim Williams"
tiwill_at_seventransistorlabs.com> wrote:

"Clifford Heath" <no.spam_at_please.net> wrote in message
news:R_46E.269058$0z4.266603_at_fx03.iad...
These are cool, ferrite filled like the conicals but higher current.

https://www.coilcraft.com/4310lc.cfm
I don't understand how they can have "Flat bandwidth with high impedance
to 6 GHz" but an SRF of 235MHz. Surely if they turn capacitive above
235MHz they're still capacitive at 6GHz?
Well, think about it. If there's more than 1/4 wave of wire there, then it
must fall over at some frequency of interest, and the fields will be very
different along the coil, not just a simple gradient. The first resonance
is good, it's a parallel resonance, high Z. The second resonance, and every
other one thereafter, is bad. The only way to keep impedance high, is to
absorb those resonances in a loss element.

If you use a tapped coil, you can add taps at strategic points, to dampen
across the antinodes of each resonance of interest.

If you use a solenoid or toroidial coil, a lossy material inside -- and
outside, mind, because the fields are external at these frequencies -- can
dampen that.

This keeps impedance flat, and a flat impedance must necessarily be lossy.
The loss sink is the core material.

Note that you can't simply taper the coil (coreless), or do a progressive
wound solenoid or whatever. There _must_ be a loss sink somewhere,
otherwise you're just making resonators in different shapes!

If you use a conical coil, you're really making a conical spiral antenna,
which has circular polarization and good directivity. Direct that energy
into a wad of ferrite, and it's gone forever -- rather than reflecting and
causing peaks and dips.

I don't think there's really anything very special that you can do with a
conical. The self-similar shape may make it easier to get a flat impedance,
but that impedance still isn't going to be very high, on account of how much
of the spiral is inducting versus how much is absorbing.

Tim

A conical inductor is the distributed equivalent of the old trick of
putting progressively larger damped inductors in series.

Take a look at these impedance curves:

https://www.coilcraft.com/pdfs/bcl.pdf




Mmmmh. I wonder how truthful these plots are. Just looking
at the S11 plot for the 0.22uH coil, we see S11 starting off
at a little below -40dB at 50MHz. Presumably, this is basically
the coil in parallel with the NA Port 2. Yet, at 50MHz, the coil
is only j11 Ohms at most, with losses making it appear even lower.
I'd have expected S11 to be pretty poor. (I'm too lazy at this
point to drag out a Smith chart to see how poor.)

Jeroen Belleman

piglet
Guest

Tue Feb 05, 2019 5:45 pm   



On 2/5/2019 12:26 AM, John Larkin wrote:
Quote:
On Mon, 4 Feb 2019 18:27:24 -0500, bitrex <user_at_example.net> wrote:

On 02/04/2019 05:28 PM, John Larkin wrote:

https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.



Capacitor and two pieces of wire?

https://www.dropbox.com/s/hz4wj3fltsetqqj/Amazon_Tee.jpg?dl=0



Just one inductor? Magic L1 covers 0.01-6Ghz!

piglet


Guest

Tue Feb 05, 2019 5:45 pm   



On Monday, February 4, 2019 at 5:28:11 PM UTC-5, John Larkin wrote:
Quote:
https://www.amazon.com/gp/product/B07D1GMXMD/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

We needed some bias tees so I tried Amazon. Prime, extra $4 for
overnight delivery.

Amazon is amazing.

We TDRd them, and they really are pretty good 6 GHz tees.

Gotta open one up and see what's inside.


You'll ruin it if you open it.

http://www.microwavejournal.com/articles/2809-a-broadband-microwave-choke

These things have been around 20 years.
Quote:


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com


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