EMRFD Message Archive 11958
Message Date From Subject 11958 2015-12-07 12:00:29 n1vc NPO capacitors Hi, I am trying to stock up my QRP lab with NPO or COG capacitors (I think they are the same thing) in a grab bag form? Maybe grab bag is the wrong term, let's say an assorted collection of common values. Can someone recommend a site that will accept preferably Paypal or at least Credit cards? I am too lazy in my old age to deal with the inconvenience of money orders, etc. Thanks Vince N1VC 11959 2015-12-07 12:21:51 Mike Re: NPO capacitors Try danssmallpartsandkits.net (Dan's small parts). I don't think they take credit cards, but I believe they do take personal checks.
I've place many orders with Dan over the years and I am a satisfied customer (with no affiliation).
11960 2015-12-07 12:28:24 K5ESS Re: NPO capacitors
Here’s one possibility. Might be others on Ebay as well.
11961 2015-12-07 12:47:55 chuck adams Re: NPO capacitors
11962 2015-12-07 13:09:51 Rod Re: NPO capacitors Hi Mike
digikey.com has no minimum order dollar value, and they
have an incredible stock of parts. Plenty of C0G and NPO
11963 2015-12-07 21:01:59 Tayloe, Dan (Noki... Re: NPO capacitors
I think that I saw somewhere that things are changing enough in ceramics used for caps that NPO/COG for some brands might not be what they used to be. The NPO/COG label is simply meeting a temperature vs. change graph target and not necessarily “NPO” as you are hoping they would be.
I have always had good success with the Xicon disc caps from Mouser. Go to Mouser and search for “Xicon Ceramic Disc Capacitors“
From the pick list select “NPO/COG” and “50v”. You should then see the full line of reasonably good Xicon NPO disc caps.
If you want surface mounted caps, I cannot help you except to recommend that you use 1206/0805 sized parts and not something smaller. The smaller the part, the more likely a higher capacity, less stable ceramic will be used.
By the way, polystyrene caps that we use to stabilize VFOs (~N220 temperature compensating) are drying up as well. Xicon happens to make those as well. In Mouser look up Xicon Film Capacitors, then pick polystyrene from the pick list.
- Dan, N7VE
11968 2015-12-08 09:20:51 Prem Re: NPO capacitors Vince, if your immediate requirement (as opposed to stocking) is just a couple of specific values of C0G, I can send them to you free in an SASE.Let me know and I'll see if I have those values in my collection. SMDs only (no through-hole in my collection).Prem.
11970 2015-12-08 10:37:30 Lee Hiers Re: NPO capacitors 11971 2015-12-08 11:35:44 Tayloe, Dan (Noki... Re: NPO capacitors As close to zero as possible as opposed to being as close to the specification limit for COG as possible.
Sent from my Windows Phone
11972 2015-12-08 12:21:05 Ekwik Re: NPO capacitors 11973 2015-12-08 12:39:46 n1vc Re: NPO capacitors First of all thanks for all of the responses. No, I don't have an immediate need, I am just stocking up on parts I think I will possibly need in the future. Vince 11974 2015-12-08 12:54:05 Bill Carver Re: NPO capacitors EXCELLENT information Ekwik
11989 2015-12-10 15:31:11 afu Re: NPO capacitors Hi,
in the past people used a intelligent way of compensatimg the
thermal coefficient of the coil - when needed - with a NON NP0
The world was strange and it change to be strange in a different waz !
Am 08.12.2015 19:35, schrieb 'Tayloe, Dan (Nokia - US/Irving)'
> As close to zero as possible as opposed to being as close to the specification limit for COG as possible.
> - Dan
> Sent from my Windows Phone
11990 2015-12-10 15:31:34 afu Re: NPO capacitors Am 08.12.2015 19:35, schrieb 'Tayloe, Dan (Nokia - US/Irving)'
> As close to zero as possible as opposed to being as close to the specification limit for COG as possible.Hi ,
it is sometime more interesting to have a capacitor with a dielectric
behaviour that is NOt depending on field strenght / voltage.
But even there NP0 is the best solution in manz cases !
> - Dan
> Sent from my Windows Phone