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Ayab
Joined: Oct 27, 2015 Posts: 180 Location: London, UK
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Posted: Fri Jan 08, 2016 2:58 pm Post subject:
Ceramic Capacitor details Subject description: Ceramic Capacitor's for Ian Fritz modules |
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Hi There Folks
I am looking to build some Ian Fritz designs from pcb's and have downloaded the parts lists from Elby designs.
I want to use source the parts myself (and use some I have already where possible) but am a little unsure about the details (in bold) of some of the ceramic capacitors listed:
The 5 Pulser bom lists:
10pF 5% Ceramic, NPO
56pF 5% Ceramic, Low K
The Chaotica bom lists:
100pF 5% Ceramic C0G
Is it essential to specify "NPO, Low or COG". Some googling has not made me much wiser. I am sure they are detailed for good reason but can I get away with normal ceramic or mcc?
Also can I substitute polystyrene for Mylar with these IF designs? I know some people here do with other designs - are there any rules of thumb on these things.
Obviously I would not want to jeopardise a module operating properly for the sake of a few components but overall the costs do build up considerably. I have been putting a lot of time into learning about all this from scratch but I feel that I am hitting a bit of an obstacle . Please help.
Best wishes to all for 2016 Last edited by Ayab on Fri Jan 08, 2016 4:17 pm; edited 1 time in total |
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thermionicjunky
Joined: Dec 07, 2006 Posts: 90 Location: san francisco
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Posted: Fri Jan 08, 2016 3:14 pm Post subject:
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The 0 in C0G and NP0 is a zero. It's a very stable ceramic. You could use silver mica for the 10pf, but I would not use a regular ceramic.
Polystyrene is a very stable film cap. It may be overkill, and they are heat-sensitive (easy to damage), but it will work very well. Polypropylene is somewhere between polystyrene and polyester(mylar) in general quality. |
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Ayab
Joined: Oct 27, 2015 Posts: 180 Location: London, UK
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Posted: Fri Jan 08, 2016 5:52 pm Post subject:
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Hi Thermionic
Really appreciate the wisdom and will take your advice and stick to the spec.
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Ayab
Joined: Oct 27, 2015 Posts: 180 Location: London, UK
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Posted: Fri Jan 08, 2016 8:04 pm Post subject:
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What about "Low K"?
Will I get away with a cheapo multilayered ceramic? |
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thermionicjunky
Joined: Dec 07, 2006 Posts: 90 Location: san francisco
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Posted: Sat Jan 09, 2016 10:59 am Post subject:
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Ayab wrote: | What about "Low K"?
Will I get away with a cheapo multilayered ceramic? |
It seems like the easiest way to find low-K is to search for NP0 or C0G. Low-K may also be referred to as Class 1. Other common ceramics will likely have mid-to-high-K. |
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Ayab
Joined: Oct 27, 2015 Posts: 180 Location: London, UK
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Posted: Sat Jan 09, 2016 1:55 pm Post subject:
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Hi thermionicjunky
Ok, ok
Hope you are having a good weekend. |
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