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.

Hi Paul,
E-mail me directly and let me know how many poles you need. I
have the AADE program, and I will be glad to do that for you.

Pete

"Paul Burridge" wrote in message
...
On Fri, 05 Mar 2004 11:28:51 GMT, Active8
wrote:

He already has a book with a fair amount of tables and all the
explainations on how to go about the design. I'm wondering WTF
here. Hey paul. wtf?

Fair point. I just wondered if anyone had a design similar to
requirements *already* lying around they might post it, that's all.
Save me a bit of scrawling and button-pushing. I didn't wish to put
anyone out.
Thanks to all who responded, BTW. Some very useful steers.
--

The BBC: Licensed at public expense to spread lies.

On Fri, 05 Mar 2004 16:18:32 +0000, Paul Burridge wrote:

On Fri, 05 Mar 2004 11:28:51 GMT, Active8
wrote:

He already has a book with a fair amount of tables and all the
explainations on how to go about the design. I'm wondering WTF
here. Hey paul. wtf?

Fair point. I just wondered if anyone had a design similar to
requirements *already* lying around they might post it, that's all.
Save me a bit of scrawling and button-pushing. I didn't wish to put
anyone out.
Thanks to all who responded, BTW. Some very useful steers.

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.
--
Best Regards,
Mike

On Fri, 05 Mar 2004 11:28:51 GMT, Active8
wrote:

He already has a book with a fair amount of tables and all the
explainations on how to go about the design. I'm wondering WTF
here. Hey paul. wtf?

Fair point. I just wondered if anyone had a design similar to
requirements *already* lying around they might post it, that's all.
Save me a bit of scrawling and button-pushing. I didn't wish to put
anyone out.
Thanks to all who responded, BTW. Some very useful steers.
--

The BBC: Licensed at public expense to spread lies.

On Thu, 04 Mar 2004 17:58:26 -0800, John Larkin wrote:

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).

wtf?

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

He already has a book with a fair amount of tables and all the
explainations on how to go about the design. I'm wondering WTF
here. Hey paul. wtf?

--
Best Regards,
Mike

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.

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,




Remove "HeadFromButt", before replying by email.

On Fri, 05 Mar 2004 03:08:22 GMT, maxfoo wrote:

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 L=1uH sorry!
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



how did that decimal point get there on plc 3 0??
inductors should all be 1 microhenry.




Remove "HeadFromButt", before replying by email.

On Fri, 05 Mar 2004 03:08:22 GMT, maxfoo wrote:

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 L=1uH sorry!
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



how did that decimal point get there on plc 3 0??
inductors should all be 1 microhenry.




Remove "HeadFromButt", before replying by email.

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.)

Lots of books out there with normalized tables. Go to a technical
university library and spend a few hours pouring thru some filter
books. You can use Linear Technology's FilterCad to see what sort of
filter type and order you need. Then hit the tables and make an LC
filter. The best book I have found is "Simplified Modern Filter
Design" by Philip Geffe, circa 1963. You can sometimes find this book
in a university technical library. It has an excellent treatment of
basic filter design and how to go from a low-pass prototype to other
filter types.

For your particular filter, you might consider a loose-coupled design,
also called coupled resonators. Good for Q 10. Your design will just
fit into this category if you don't mind some imperfection. This type
of design produces nice component values. "Electronic Filter Design
Handbook", by Arthur Williams and Fred Taylor (ISBN 0-07-070434-1),
page 5-19 has info.

Mark