[600MRG] Capacitors

[Brian, WA1ZMS]

Larry-

Here's a .01uF that Mouser shows as having 1,931 in-stock:

http://www.mouser.com/Search/m_ProductDetail.aspx?Cornell-Dubilier-CDE%2f715P10356KD3%2f&qs=sGAEpiMZZMv1cc3ydrPrF%2fQMTT%2fqsvz6uoNY%252bMc%2fkKY%3



-Brian, WA1ZMS
iPhone

> On Oct 5, 2017, at 7:52 PM, david vanhorn <kc6ete at gmail.com> wrote:
> 
> Have you looked at X2Y caps from Johanson or similar parts?  Virtually no
> self-inductance.  Also balancing between the sections is very close if you
> choose to use them as a pair of caps rather than one high Q cap.
> 
> 
>> On Thu, Oct 5, 2017 at 1:32 PM, Larry Molitor <w7iuv at yahoo.com> wrote:
>> 
>> First of all thanks to all those who responded.
>> My specific application (this time) is receiver bandpass filters. So....
>> Size is important.
>> Cost is important. With a total cost of the receiver less than $30 it
>> makes no sense at all to spend $50 for filter caps.
>> Q is more important in a bandpass filter than in a typical low pass
>> filter. Caps I've used successfully in TX low pass designs are not
>> acceptable in these bandpass designs. The bandpass designs I'm using
>> require much higher values of "C" than low pass designs for the same
>> frequency. Most, if not all, of the hi-Q caps I've been using for low pass
>> filters are simply not available in the higher values of "C" that I need.
>> Rudy,
>> The old transmit micas are too big. I have a box of them myself but it
>> seems like I never bothered to pick up many of the high values. Most are
>> less than 1000 pF. One of the few that was marked at 0.03 uF / 1000V, was
>> measured and I saw one of the lowest ESR's of anything I have here.
>> Marshall,
>> ATC caps are great. I've been using them for VHF through microwave for
>> decades. Unfortunately the high Q 100B's are not available in the values I
>> need. Some of the bigger case sizes are on special order but they don't
>> have as high Q. Even so at 4 bux a pop, I'm not going to buy any.
>> Brian,
>> The Vishay 715P seems to be an obsolete part. At least i cannot find any
>> "new" stock. Mouser does stock a number of Vishay parts that may be
>> equivalent and the catalog claims decent (but not outstanding) Q. Price and
>> size are reasonable so I might be looking at getting some. If you could
>> measure the Q/ESR of some of the parts you have, I'd appreciate it.
>> Frank,
>> Paralleling caps doesn't help the ESR. A cap with half the "C" will have
>> approximately twice the ESR. What you do gain is more surface area to
>> dissipate the same heat generated. The caps are then cooler to the touch
>> and you feel better even though you didn't gain anything except perhaps
>> reliability.