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-   -   Wanted: bandpass filter design (https://www.radiobanter.com/homebrew/22504-wanted-bandpass-filter-design.html)

Paul Burridge March 4th 04 11:43 PM

Wanted: bandpass filter design
 
Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.
--

The BBC: Licensed at public expense to spread lies.

Peter O. Brackett March 5th 04 12:41 AM

Paul:

[snip]
I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)

[snip]

Such a design can be achieved with a vert simple formula and a pocket
calculator or slide rule. Why don't you just use Bennett's simple formula
for the maximally flat approximation all pole element values, or Takashi's
simple formulae for the equiripple approximation all pole element values?

Oh... perhaps you want elliptic [Cauer or Darlington] designs or perhaps a
completely general parameter design in that case ypu will need a computer
and will need to do some programming or buy some programming, or
better yet...

Hire a consultant... :-)

Hey, I've designed literally thousands of LC filters over decades in most
frequency ranges, for clients who have paid me well. I have access to very
sophisticated and comprehensive general parameter LC filter design
programs that I have written [In Fortran BTW] over lo these many years
and they are immediately at my disposal.

But... unfortunately for some... I never design filters for free!

I'll do it for you at my usual consulting rates.

My rates are reasonable. Just call or email me to discuss the terms and
conditions.

:-)

--
Peter
Professional Consultant - Signal Processing and Analog Electronics
Indialantic By-the-Sea, FL
peter dot brackett at "eye" triple "e" dot org.
USA area code three two one, number seven two three, nine two five five.


"Paul Burridge" wrote in message
...
Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.
--

The BBC: Licensed at public expense to spread lies.




Peter O. Brackett March 5th 04 12:41 AM

Paul:

[snip]
I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)

[snip]

Such a design can be achieved with a vert simple formula and a pocket
calculator or slide rule. Why don't you just use Bennett's simple formula
for the maximally flat approximation all pole element values, or Takashi's
simple formulae for the equiripple approximation all pole element values?

Oh... perhaps you want elliptic [Cauer or Darlington] designs or perhaps a
completely general parameter design in that case ypu will need a computer
and will need to do some programming or buy some programming, or
better yet...

Hire a consultant... :-)

Hey, I've designed literally thousands of LC filters over decades in most
frequency ranges, for clients who have paid me well. I have access to very
sophisticated and comprehensive general parameter LC filter design
programs that I have written [In Fortran BTW] over lo these many years
and they are immediately at my disposal.

But... unfortunately for some... I never design filters for free!

I'll do it for you at my usual consulting rates.

My rates are reasonable. Just call or email me to discuss the terms and
conditions.

:-)

--
Peter
Professional Consultant - Signal Processing and Analog Electronics
Indialantic By-the-Sea, FL
peter dot brackett at "eye" triple "e" dot org.
USA area code three two one, number seven two three, nine two five five.


"Paul Burridge" wrote in message
...
Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.
--

The BBC: Licensed at public expense to spread lies.




Harold E. Johnson March 5th 04 01:49 AM

Conversely, go to the WB6BLD website and download the free student version
of Elsie and do it yourself, will take an hour to learn the software and 5
minutes to design the filter. Another good filter program that is free and
available and relatively easy to use is at the AADE website.

Would be worth your while to learn even if you seldom design a filter.

W4ZCB
"Peter O. Brackett" wrote in message
hlink.net...
Paul:

[snip]
I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)

[snip]

Such a design can be achieved with a vert simple formula and a pocket
calculator or slide rule. Why don't you just use Bennett's simple formula
for the maximally flat approximation all pole element values, or Takashi's
simple formulae for the equiripple approximation all pole element values?

Oh... perhaps you want elliptic [Cauer or Darlington] designs or perhaps a
completely general parameter design in that case ypu will need a computer
and will need to do some programming or buy some programming, or
better yet...

Hire a consultant... :-)

Hey, I've designed literally thousands of LC filters over decades in most
frequency ranges, for clients who have paid me well. I have access to

very
sophisticated and comprehensive general parameter LC filter design
programs that I have written [In Fortran BTW] over lo these many years
and they are immediately at my disposal.

But... unfortunately for some... I never design filters for free!

I'll do it for you at my usual consulting rates.

My rates are reasonable. Just call or email me to discuss the terms and
conditions.

:-)

--
Peter
Professional Consultant - Signal Processing and Analog Electronics
Indialantic By-the-Sea, FL
peter dot brackett at "eye" triple "e" dot org.
USA area code three two one, number seven two three, nine two five five.


"Paul Burridge" wrote in message
...
Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.
--

The BBC: Licensed at public expense to spread lies.






Harold E. Johnson March 5th 04 01:49 AM

Conversely, go to the WB6BLD website and download the free student version
of Elsie and do it yourself, will take an hour to learn the software and 5
minutes to design the filter. Another good filter program that is free and
available and relatively easy to use is at the AADE website.

Would be worth your while to learn even if you seldom design a filter.

W4ZCB
"Peter O. Brackett" wrote in message
hlink.net...
Paul:

[snip]
I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)

[snip]

Such a design can be achieved with a vert simple formula and a pocket
calculator or slide rule. Why don't you just use Bennett's simple formula
for the maximally flat approximation all pole element values, or Takashi's
simple formulae for the equiripple approximation all pole element values?

Oh... perhaps you want elliptic [Cauer or Darlington] designs or perhaps a
completely general parameter design in that case ypu will need a computer
and will need to do some programming or buy some programming, or
better yet...

Hire a consultant... :-)

Hey, I've designed literally thousands of LC filters over decades in most
frequency ranges, for clients who have paid me well. I have access to

very
sophisticated and comprehensive general parameter LC filter design
programs that I have written [In Fortran BTW] over lo these many years
and they are immediately at my disposal.

But... unfortunately for some... I never design filters for free!

I'll do it for you at my usual consulting rates.

My rates are reasonable. Just call or email me to discuss the terms and
conditions.

:-)

--
Peter
Professional Consultant - Signal Processing and Analog Electronics
Indialantic By-the-Sea, FL
peter dot brackett at "eye" triple "e" dot org.
USA area code three two one, number seven two three, nine two five five.


"Paul Burridge" wrote in message
...
Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.
--

The BBC: Licensed at public expense to spread lies.






John Larkin March 5th 04 01:58 AM

On Thu, 04 Mar 2004 23:43:21 +0000, Paul Burridge
wrote:

Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.


The usual technique is to get a book that has tables of normalized LC
lowpass filters of various types, pick a response you like, and scale
it and map to a bandpass. Williams' "Electronic Filter Design
Handbook" has all this stuff.

It's mildly tedious, so I won't offer to do one for you.

John


John Larkin March 5th 04 01:58 AM

On Thu, 04 Mar 2004 23:43:21 +0000, Paul Burridge
wrote:

Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.


The usual technique is to get a book that has tables of normalized LC
lowpass filters of various types, pick a response you like, and scale
it and map to a bandpass. Williams' "Electronic Filter Design
Handbook" has all this stuff.

It's mildly tedious, so I won't offer to do one for you.

John


Jeffrey Turner March 5th 04 02:03 AM

Paul Burridge wrote:

Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)


If you have Office 2002 (XP), you can use this web site.

http://www.rfcafe.com/references/_sp...er_plot_ss.htm

--
A man, a plan, a cat, a canal - Panama!

Ho, ho, ho, hee, hee, hee
and a couple of ha, ha, has;
That's how we pass the day away,
in the merry old land of Oz.


Jeffrey Turner March 5th 04 02:03 AM

Paul Burridge wrote:

Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)


If you have Office 2002 (XP), you can use this web site.

http://www.rfcafe.com/references/_sp...er_plot_ss.htm

--
A man, a plan, a cat, a canal - Panama!

Ho, ho, ho, hee, hee, hee
and a couple of ha, ha, has;
That's how we pass the day away,
in the merry old land of Oz.


maxfoo March 5th 04 03:08 AM

On Thu, 04 Mar 2004 23:43:21 +0000, Paul Burridge
wrote:

Hi all,

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,
corner frequencies one Meg or therabouts either side of that and a
reasonably good shape factor (nothing critical here). I don't mind
having to do a bit of tweaking of values myself if anyone has
something close to that they can post. Passive L/C combinations only,
please. (assume the usual 50R nominal Zs.)
Thanks,

p.


Try this 5 pole Chebychev with 0.1dB ripple

Fc=17.2MHz BW=1MHz

CAP 1 2 C=27PF
PLC 2 0 L=1uH C=56PF
CAP 2 3 C=4PF
PLC 3 0 L=.1uH C=80PF
CAP 3 4 C=3PF
PLC 4 0 L=1uH C=80PF
CAP 4 5 C=3PF
PLC 5 0 L=1uH C=80PF
CAP 5 6 C=4PF
PLC 6 0 L=1uH C=56PF
CAP 6 7 C=27PF


tia,




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