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

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,

============================

Hello Paul,

I'm not in the habit of fishing for compliments but, out of curiosity, did
you find my program BANDPAS1 of more use to you than the many other
responses to your query.

By the way, the Pi-network filter can be matched to ANY pair of terminating
impedances by tapping down the coils at each end. Been there - done that.
It also allows the most convenient component values to be used.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,

============================

Hello Paul,

I'm not in the habit of fishing for compliments but, out of curiosity, did
you find my program BANDPAS1 of more use to you than the many other
responses to your query.

By the way, the Pi-network filter can be matched to ANY pair of terminating
impedances by tapping down the coils at each end. Been there - done that.
It also allows the most convenient component values to be used.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........

Error. My previous message was intended to be by private e-mail.
---
Reg

Error. My previous message was intended to be by private e-mail.
---
Reg

On Fri, 05 Mar 2004 23:40:43 GMT, Active8
wrote:

Yes. I had to check my disorganized drive to make sure I'd been to
all those links. BTDT. I like having tools like that around to
compare what they say with what I figgered out on paper.

Indeed. Legendary Reg's programs are always well worth a look at, of
course. I did try out his filter design one last night, just out of
curiosity. Looks pretty neat. I'll run some sims through it later to
see what sort of results it gives. Might post the results later if
time permits...

--

The BBC: Licensed at public expense to spread lies.

On Fri, 05 Mar 2004 23:40:43 GMT, Active8
wrote:

Yes. I had to check my disorganized drive to make sure I'd been to
all those links. BTDT. I like having tools like that around to
compare what they say with what I figgered out on paper.

Indeed. Legendary Reg's programs are always well worth a look at, of
course. I did try out his filter design one last night, just out of
curiosity. Looks pretty neat. I'll run some sims through it later to
see what sort of results it gives. Might post the results later if
time permits...

--

The BBC: Licensed at public expense to spread lies.

On Sat, 6 Mar 2004 14:06:58 +0000 (UTC), "Reg Edwards"
wrote:

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,

============================

Hello Paul,

I'm not in the habit of fishing for compliments but, out of curiosity, did
you find my program BANDPAS1 of more use to you than the many other
responses to your query.

Thanks, Reg. See my reply to Mike (Active8) elsewhere on this thread.
I'm one of your biggest admirers and you've always been something of a
folk hero to me. :-)

By the way, the Pi-network filter can be matched to ANY pair of terminating
impedances by tapping down the coils at each end. Been there - done that.
It also allows the most convenient component values to be used.

Noted.
--

The BBC: Licensed at public expense to spread lies.

On Sat, 6 Mar 2004 14:06:58 +0000 (UTC), "Reg Edwards"
wrote:

I need a simple design for a BPF with a centre frequency of 17.2Mhz.,

============================

Hello Paul,

I'm not in the habit of fishing for compliments but, out of curiosity, did
you find my program BANDPAS1 of more use to you than the many other
responses to your query.

Thanks, Reg. See my reply to Mike (Active8) elsewhere on this thread.
I'm one of your biggest admirers and you've always been something of a
folk hero to me. :-)

By the way, the Pi-network filter can be matched to ANY pair of terminating
impedances by tapping down the coils at each end. Been there - done that.
It also allows the most convenient component values to be used.

Noted.
--

The BBC: Licensed at public expense to spread lies.

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.