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-   -   Polystyrene capacitors for filter networks? (https://www.radiobanter.com/homebrew/22617-polystyrene-capacitors-filter-networks.html)

Gregg March 18th 04 05:27 AM

Behold, qrk signalled from keyed 4-1000A filament:

On Wed, 17 Mar 2004 12:03:06 +0000, Paul Burridge
wrote:

Hi,

They look worryingly inductive on visual inspection (there are metal
foils rolled up in thar by the look of it.) And yet the CPC catalogue
says that their properties make them ideal for use in filters. Has
anyone any remarks (favourable or otherwise) to make about the use of
this type of cap in filter apps?

p.


They're great for LC filters. If you choose your ferrite right, you can
have a pretty stable filter over temperature.


Air-core my good man, air-core ;-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

Terry Given March 19th 04 02:17 AM

"Paul Burridge" wrote in message
...
On Wed, 17 Mar 2004 15:45:34 -0000, "Emoneg"
wrote:


"Paul Burridge" wrote in message
.. .
| Hi,
|
| They look worryingly inductive on visual inspection (there are metal
| foils rolled up in thar by the look of it.) And yet the CPC catalogue
| says that their properties make them ideal for use in filters. Has
| anyone any remarks (favourable or otherwise) to make about the use of
| this type of cap in filter apps?


Silly boy......


Sorry. I'll try not to ask such *stupid* questions again.


no stupid questions, unless you ignored the answers last time.....

remember, things you know are easy. Its the things you dont know that are
hard.




Terry Given March 19th 04 02:17 AM

"Paul Burridge" wrote in message
...
On Wed, 17 Mar 2004 15:45:34 -0000, "Emoneg"
wrote:


"Paul Burridge" wrote in message
.. .
| Hi,
|
| They look worryingly inductive on visual inspection (there are metal
| foils rolled up in thar by the look of it.) And yet the CPC catalogue
| says that their properties make them ideal for use in filters. Has
| anyone any remarks (favourable or otherwise) to make about the use of
| this type of cap in filter apps?


Silly boy......


Sorry. I'll try not to ask such *stupid* questions again.


no stupid questions, unless you ignored the answers last time.....

remember, things you know are easy. Its the things you dont know that are
hard.




qrk March 19th 04 02:35 AM

On Thu, 18 Mar 2004 05:27:09 GMT, Gregg wrote:

Behold, qrk signalled from keyed 4-1000A filament:

On Wed, 17 Mar 2004 12:03:06 +0000, Paul Burridge
wrote:

Hi,

They look worryingly inductive on visual inspection (there are metal
foils rolled up in thar by the look of it.) And yet the CPC catalogue
says that their properties make them ideal for use in filters. Has
anyone any remarks (favourable or otherwise) to make about the use of
this type of cap in filter apps?

p.


They're great for LC filters. If you choose your ferrite right, you can
have a pretty stable filter over temperature.


Air-core my good man, air-core ;-)


Try air-core with 500+ uH. Then pack em in to a small area. That's
what I get for being a low-freq weenie.


qrk March 19th 04 02:35 AM

On Thu, 18 Mar 2004 05:27:09 GMT, Gregg wrote:

Behold, qrk signalled from keyed 4-1000A filament:

On Wed, 17 Mar 2004 12:03:06 +0000, Paul Burridge
wrote:

Hi,

They look worryingly inductive on visual inspection (there are metal
foils rolled up in thar by the look of it.) And yet the CPC catalogue
says that their properties make them ideal for use in filters. Has
anyone any remarks (favourable or otherwise) to make about the use of
this type of cap in filter apps?

p.


They're great for LC filters. If you choose your ferrite right, you can
have a pretty stable filter over temperature.


Air-core my good man, air-core ;-)


Try air-core with 500+ uH. Then pack em in to a small area. That's
what I get for being a low-freq weenie.


Gregg March 19th 04 06:43 AM

Behold, qrk signalled from keyed 4-1000A filament:


Air-core my good man, air-core ;-)


Try air-core with 500+ uH. Then pack em in to a small area. That's what
I get for being a low-freq weenie.


Ah! I too am a LowFER - Made a 6Hy coil in about 4 sq. inches on my
winding jig. No current capacity but a great 20-76KHz preselect for the
vacuum tube RX :-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

Gregg March 19th 04 06:43 AM

Behold, qrk signalled from keyed 4-1000A filament:


Air-core my good man, air-core ;-)


Try air-core with 500+ uH. Then pack em in to a small area. That's what
I get for being a low-freq weenie.


Ah! I too am a LowFER - Made a 6Hy coil in about 4 sq. inches on my
winding jig. No current capacity but a great 20-76KHz preselect for the
vacuum tube RX :-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca


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