¿ªÔÆÌåÓýThe performance of ceramic caps depends on the exact type of material.? npo type are very good ,? it is the "hi k" type that have problems.? Temperature compensating caps have charities similar to NPO.? The best performance overall is polypropylene.? Look up polypropylene and mylar to see the differences.? Old tubular caps are not all paper but most are. Plastic film caps are in all ways superior. -------- Original message -------- From: Gary Follett <xntrick1948@...> Date: 3/21/23 10:21 AM (GMT-08:00) Subject: Re: [DRAKE-RADIO] Rob, Question re your "Custom Front Panel Switch" mod The tubular ones to which you refer are, at this radio¡¯s vintage, paper capacitors. They are non-polarized except for the fact that the outermost metallization is typically tied to ground to reduce noise pickup and to ensure that the outermost layer is at ground potential. That is why these types often (not always) have a band on one end to indicate which end should be grounded. To replace these capacitors, the best choice would be modern Mylar capacitors, readily available for DigiKey or Mouser. I always buy 630 volt devices so I only need to stock one drawer of each value. There is no downside to using higher than needed voltage rated parts, other than size. However, the modern parts are so much smaller than the originals that this is not an issue. The biggest issue with modern parts is that the leads are often not long enough to reach the tie points in older radios (particularly in Collins radios). That won¡¯t be a problem generally with Drake radios though. Gary W0DVN
|
