10 MHz low pass filter
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
On 6/20/2012 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
Joe that is a nice price and good looking board.
Interesting to see what you get and how it does.
Regards
Paul
WB8TSL
Hi
That's a pretty high order filter. The output of most OCXO's already has a filter on it. Combining two filters (especially high order ones) without isolation between them is not a good idea. The resulting transfer function will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
If the output is buffered, there really shouldn't be a problem.
Incidentally, I can crank out high order LCR filters all day just by transforming prototypes out of Zverev. But it has been my experience at even 10MHz the parasitics of the elements will throw off the design.
-----Original Message-----
From: Bob Camp lists@rtty.us
Sender: time-nuts-bounces@febo.com
Date: Wed, 20 Jun 2012 17:49:37
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz low pass filter
Hi
That's a pretty high order filter. The output of most OCXO's already has a filter on it. Combining two filters (especially high order ones) without isolation between them is not a good idea. The resulting transfer function will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Based on that PCB, I want to see an sweep to at least 1GHz.
The reason is that experience have shown that the inductance (perhaps 10nH)
in series with C2 and C6 would damage the stop-band rejection at UHF.
Used with an OXCO this would not matter, but the desire to make the
ultimate filter is still there.
Thomas.
2012/6/21 lists@lazygranch.com
If the output is buffered, there really shouldn't be a problem.
Incidentally, I can crank out high order LCR filters all day just by
transforming prototypes out of Zverev. But it has been my experience at
even 10MHz the parasitics of the elements will throw off the design.
-----Original Message-----
From: Bob Camp lists@rtty.us
Sender: time-nuts-bounces@febo.com
Date: Wed, 20 Jun 2012 17:49:37
To: Discussion of precise time and frequency measurement<
time-nuts@febo.com>
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz low pass filter
Hi
That's a pretty high order filter. The output of most OCXO's already has a
filter on it. Combining two filters (especially high order ones) without
isolation between them is not a good idea. The resulting transfer function
will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
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and follow the instructions there.
--
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See http://www.gnu.org/philosophy/no-word-attachments.html
PDF is an better alternative and there are always LaTeX!
I thought I'd put one on a FE-5680A and see what happens to the third
harmonic. It might also be interesting to see if I get a decent sine
wave out of the filter with a square wave in.
Joe Gray
W5JG
On Wed, Jun 20, 2012 at 3:49 PM, Bob Camp lists@rtty.us wrote:
Hi
That's a pretty high order filter. The output of most OCXO's already has a filter on it. Combining two filters (especially high order ones) without isolation between them is not a good idea. The resulting transfer function will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
In the days when I had access to a network analyzer with a chip component fixture (all calibrated of course), I tested components on hand just to see how ideal they were. Chip resistors are quite good. The inductance is basically the electrical length of the device. Caps can be decent. My recollection is Johanson had some really good (low parasitic) caps. Inductors basically suck.
You will note in most RF board design with lumped elements, they rotate adjacent inductors to reduce mutual inductance.
10MHz is probably too low in frequency for practical stripline. You could probably do active filters these days, but the power budget would not be trivial.
-----Original Message-----
From: "Thomas S. Knutsen" la3pna@gmail.com
Date: Thu, 21 Jun 2012 01:17:02
To: lists@lazygranch.com; Discussion of precise time and frequency measurementtime-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz low pass filter
Based on that PCB, I want to see an sweep to at least 1GHz.
The reason is that experience have shown that the inductance (perhaps 10nH)
in series with C2 and C6 would damage the stop-band rejection at UHF.
Used with an OXCO this would not matter, but the desire to make the
ultimate filter is still there.
Thomas.
2012/6/21 lists@lazygranch.com
If the output is buffered, there really shouldn't be a problem.
Incidentally, I can crank out high order LCR filters all day just by
transforming prototypes out of Zverev. But it has been my experience at
even 10MHz the parasitics of the elements will throw off the design.
-----Original Message-----
From: Bob Camp lists@rtty.us
Sender: time-nuts-bounces@febo.com
Date: Wed, 20 Jun 2012 17:49:37
To: Discussion of precise time and frequency measurement<
time-nuts@febo.com>
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz low pass filter
Hi
That's a pretty high order filter. The output of most OCXO's already has a
filter on it. Combining two filters (especially high order ones) without
isolation between them is not a good idea. The resulting transfer function
will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Please avoid sending me Word or PowerPoint attachments.
See http://www.gnu.org/philosophy/no-word-attachments.html
PDF is an better alternative and there are always LaTeX!
I don't have any problems with rotating the inductors, after all, that is
one of the best way to avoid coupling between them, but the main problem as
I see with that board is that there are 2 caps that would become an series
resonance with the inductance in the via to reach the ground plane.
Of course, at 10MHz this is just theoretical, since the problem most
probably would appear above 500MHz, and the 50'th harmonic of an OXCO
should be low.
My experience says that the inductance in the capacitor it self should be
low, specialy if NP0 or such capacitors caps are used.
An 10MHz sallen key lowpass may be interesting to build,and with the GHz
bandwith op-amps avaible today, it should work great.
Thomas.
2012/6/21 lists@lazygranch.com
**
In the days when I had access to a network analyzer with a chip component
fixture (all calibrated of course), I tested components on hand just to see
how ideal they were. Chip resistors are quite good. The inductance is
basically the electrical length of the device. Caps can be decent. My
recollection is Johanson had some really good (low parasitic) caps.
Inductors basically suck.
You will note in most RF board design with lumped elements, they rotate
adjacent inductors to reduce mutual inductance.
10MHz is probably too low in frequency for practical stripline. You could
probably do active filters these days, but the power budget would not be
trivial.
*From: * "Thomas S. Knutsen" la3pna@gmail.com
*Date: *Thu, 21 Jun 2012 01:17:02 +0200
*To: *lists@lazygranch.com; Discussion of precise time and frequency
measurementtime-nuts@febo.com
*Subject: *Re: [time-nuts] 10 MHz low pass filter
Based on that PCB, I want to see an sweep to at least 1GHz.
The reason is that experience have shown that the inductance (perhaps
10nH) in series with C2 and C6 would damage the stop-band rejection at UHF.
Used with an OXCO this would not matter, but the desire to make the
ultimate filter is still there.
Thomas.
2012/6/21 lists@lazygranch.com
If the output is buffered, there really shouldn't be a problem.
Incidentally, I can crank out high order LCR filters all day just by
transforming prototypes out of Zverev. But it has been my experience at
even 10MHz the parasitics of the elements will throw off the design.
-----Original Message-----
From: Bob Camp lists@rtty.us
Sender: time-nuts-bounces@febo.com
Date: Wed, 20 Jun 2012 17:49:37
To: Discussion of precise time and frequency measurement<
time-nuts@febo.com>
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz low pass filter
Hi
That's a pretty high order filter. The output of most OCXO's already has
a filter on it. Combining two filters (especially high order ones) without
isolation between them is not a good idea. The resulting transfer function
will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Please avoid sending me Word or PowerPoint attachments.
See http://www.gnu.org/philosophy/no-word-attachments.html
PDF is an better alternative and there are always LaTeX!
--
Please avoid sending me Word or PowerPoint attachments.
See http://www.gnu.org/philosophy/no-word-attachments.html
PDF is an better alternative and there are always LaTeX!
Hi
The next sine wave OCXO that I see with a buffered output will be the first one. Every one I've seen has an LC filter between the output amp and the connector. If you are lucky you might have a pad, but that's not much to count on.
Bob
On Jun 20, 2012, at 7:01 PM, lists@lazygranch.com wrote:
If the output is buffered, there really shouldn't be a problem.
Incidentally, I can crank out high order LCR filters all day just by transforming prototypes out of Zverev. But it has been my experience at even 10MHz the parasitics of the elements will throw off the design.
-----Original Message-----
From: Bob Camp lists@rtty.us
Sender: time-nuts-bounces@febo.com
Date: Wed, 20 Jun 2012 17:49:37
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz low pass filter
Hi
That's a pretty high order filter. The output of most OCXO's already has a filter on it. Combining two filters (especially high order ones) without isolation between them is not a good idea. The resulting transfer function will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
Hi
The standard FE-5680 very much has an LC filter between the output amp and the output pin. I'd take out their filter and put this one in. I would not use both together.
Bob
On Jun 20, 2012, at 7:23 PM, Joseph Gray wrote:
I thought I'd put one on a FE-5680A and see what happens to the third
harmonic. It might also be interesting to see if I get a decent sine
wave out of the filter with a square wave in.
Joe Gray
W5JG
On Wed, Jun 20, 2012 at 3:49 PM, Bob Camp lists@rtty.us wrote:
Hi
That's a pretty high order filter. The output of most OCXO's already has a filter on it. Combining two filters (especially high order ones) without isolation between them is not a good idea. The resulting transfer function will not be what you expect it to be….
Bob
On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote:
I came across this filter design recently and thought I'd build a few.
http://www.jwmeng.com/AppNote/AppNote003.html
I was about to place a Mouser order when I came across someone selling
filters, based on the above design.
http://www.ebay.com/itm/10-MHz-filter-kit-for-tcxo-gps-pll-/110893777470
The price with a board seemed low enough that I ordered a few. I'll
let everyone know how they work out.
Joe Gray
W5JG
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.