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,

Since your too lazy to do this, here, have a few designs. You can run
these on LTSpice. What is reasonably good shape factor?
Mark

Butterworth, pi-input, 1st-order low-pass prototype
Vin 1 0 AC 2.0000V
Rin 1 2 50.000
L1 2 0 26.899n
C1 2 0 3.1831n
Rout 2 0 50.000
..AC DEC 396 253.58kHz 1.1667GHz
..PROBE
..END

Butterworth, pi-input, 2nd-order low-pass prototype
Vin 1 0 AC 2.0000V
Rin 1 2 50.000
L1 2 0 38.041n
C1 2 0 2.2508n
L2 2 3 5.6270u
C2 3 4 15.216p
Rout 4 0 50.000
..AC DEC 792 5.7378MegHz 51.560MegHz
..PROBE
..END

Butterworth, loose coupled, 2nd-order low-pass prototype
Vin 1 0 AC 2.0000V
Rin 1 2 50.000
C1 2 0 2.0654nF
L1 2 0 38.046nH
C2 2 3 185.01pF
C3 3 0 2.0654nF
L2 3 0 38.046nH
Rout 3 0 50.000
..AC DEC 792 5.7378MegHz 51.560MegHz
..PROBE
..END

Butterworth, pi-input, 3rd-order low-pass prototype
Vin 1 0 AC 2.0000V
Rin 1 2 50.000
L1 2 0 53.798n
C1 2 0 1.5915n
L2 2 3 7.9577u
C2 3 4 10.760p
L3 4 0 53.798n
C3 4 0 1.5915n
Rout 4 0 50.000
..AC DEC 1188 10.224MegHz 28.937MegHz
..PROBE
..END

Butterworth, loose coupled, 3rd-order low-pass prototype
Vin 1 0 AC 2.0000V
Rin 1 2 50.000
C1 2 0 1.4607nF
L1 2 0 53.798nH
C2 2 3 130.84pF
C3 3 0 1.3299nF
L2 3 0 53.798nH
C4 3 4 130.84pF
C5 4 0 1.4607nF
L3 4 0 53.798nH
Rout 4 0 50.000
..AC DEC 1188 10.224MegHz 28.937MegHz
..PROBE
..END

Butterworth, loose coupled, 8th-order low-pass prototype
Vin 1 0 AC 2.0000V
Rin 1 2 50.000
C1 2 0 511.07pF
L1 2 0 137.94nH
C2 2 3 109.63pF
C3 3 0 457.95pF
L2 3 0 137.94nH
C4 3 4 53.121pF
C5 4 0 527.60pF
L3 4 0 137.94nH
C6 4 5 39.985pF
C7 5 0 543.91pF
L4 5 0 137.94nH
C8 5 6 36.809pF
C9 6 0 543.91pF
L5 6 0 137.94nH
C10 6 7 39.985pF
C11 7 0 527.60pF
L6 7 0 137.94nH
C12 7 8 53.121pF
C13 8 0 457.95pF
L7 8 0 137.94nH
C14 8 9 109.63pF
C15 9 0 511.07pF
L8 9 0 137.94nH
Rout 9 0 50.000
..AC DEC 3170 15.208MegHz 19.453MegHz
..PROBE
..END

On Fri, 05 Mar 2004 19:11:57 -0800, qrk
wrote:

Since your too lazy to do this, here, have a few designs. You can run
these on LTSpice. What is reasonably good shape factor?
Mark

Thanks Mark (and everyone else who responded) I will certainly check
this lot out later today.
I've got more than enough designs and pointers to design programs now,
so no more *please*!!! A chap *can* have too much help sometimes. :-)
--

The BBC: Licensed at public expense to spread lies.

Paul Burridge wrote in message

I've got more than enough designs and pointers to design programs now,
so no more *please*!!! A chap *can* have too much help sometimes. :-)

Note to Paul but also to everyone else:

For every person who posts a question and/or response there are
probably a thousand people who read and benefit from the information
in a thread but never post anything. You may be full up Paul, there
may also be many more readers who need more information but won't or
can't ask.

Please, everyone, continue to contribute as long as you can.

Jim

For every person who posts a question and/or response there are
probably a thousand people who read and benefit from the information
in a thread but never post anything. You may be full up Paul, there
may also be many more readers who need more information but won't or
can't ask.

Please, everyone, continue to contribute as long as you can.
=============================

Unfortunately, only about 5 percent of the 'information' published on this
and other newsgroups is of any use. Much of the remainder is misleading.
And the most serious of the problems is most folks' inability to distinguish
between wheat and chaff.

Many who are satisfied and immediately say thank you are too hasty, later
finding it won't work. Too much of the information falls into the category
of old wive's tales. If it sounds OK then it must be right!

The frequency of arguments between 'experts' gives the show away.

But most of you know this anyway. So why do I bother to say so?

Entertainment value is another matter. It stimulates the mind. Hence the
group's popularity.
---
Reg.

For every person who posts a question and/or response there are
probably a thousand people who read and benefit from the information
in a thread but never post anything. You may be full up Paul, there
may also be many more readers who need more information but won't or
can't ask.

Please, everyone, continue to contribute as long as you can.
=============================

Unfortunately, only about 5 percent of the 'information' published on this
and other newsgroups is of any use. Much of the remainder is misleading.
And the most serious of the problems is most folks' inability to distinguish
between wheat and chaff.

Many who are satisfied and immediately say thank you are too hasty, later
finding it won't work. Too much of the information falls into the category
of old wive's tales. If it sounds OK then it must be right!

The frequency of arguments between 'experts' gives the show away.

But most of you know this anyway. So why do I bother to say so?

Entertainment value is another matter. It stimulates the mind. Hence the
group's popularity.
---
Reg.

Paul Burridge wrote in message

I've got more than enough designs and pointers to design programs now,
so no more *please*!!! A chap *can* have too much help sometimes. :-)

Note to Paul but also to everyone else:

For every person who posts a question and/or response there are
probably a thousand people who read and benefit from the information
in a thread but never post anything. You may be full up Paul, there
may also be many more readers who need more information but won't or
can't ask.

Please, everyone, continue to contribute as long as you can.

Jim

On Fri, 05 Mar 2004 19:11:57 -0800, qrk
wrote:

Since your too lazy to do this, here, have a few designs. You can run
these on LTSpice. What is reasonably good shape factor?
Mark

Thanks Mark (and everyone else who responded) I will certainly check
this lot out later today.
I've got more than enough designs and pointers to design programs now,
so no more *please*!!! A chap *can* have too much help sometimes. :-)
--

The BBC: Licensed at public expense to spread lies.