Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Capacitors  (Read 2427 times)
AB2MA
Member

Posts: 47




Ignore
« on: March 02, 2008, 09:19:14 AM »

Having trouble finding mica and silver mica caps in the 1kv range.Can ceramic disc caps be used instead?
Logged
KE4DRN
Member

Posts: 3746




Ignore
« Reply #1 on: March 02, 2008, 08:00:20 PM »

hi stan,

are the mica caps damaged ?

http://www.justradios.com/capacitors.html#product

73 james

Logged
AD5X
Member

Posts: 1614




Ignore
« Reply #2 on: March 03, 2008, 04:39:52 AM »

Mouser Electronics (www.mouser.com) sells 500V and 1000V mica caps.  And you can always series two 500V caps to get 1000V (each capacitor needs to be twice the value needed when placed in series).

Phil - AD5X
Logged
AB2MA
Member

Posts: 47




Ignore
« Reply #3 on: March 03, 2008, 05:27:01 AM »

Thanks for the responses.The caps are not damaged,they are missing.I checked Mouser and everything in the 1kv range does not have the right values.Can ceramic disc be substituted?The caps are for a Heath AT-1 xmitter.Tnx again,Stan
Logged
AA9XY
Member

Posts: 6




Ignore
« Reply #4 on: March 03, 2008, 05:46:50 AM »

Try Antique Electronic Supply at www.tubesandmore.com, or RadioDaze at www.radiodaze.com. They should have the mica capacitors you are looking for.  Also, you'll probably have to pick something close to the original value, as a lot of the old, even numbered values are not made anymore.....i.e. 50 pfd has probably been supplanted by 47pfd, etc.  

I wouldn't replace silver micas with ceramic.  The ceramics are more affected by temperature and will drift in value.  
Logged
KA5N
Member

Posts: 4380




Ignore
« Reply #5 on: March 03, 2008, 10:54:34 AM »

In the case of the AT-1 (and other Heathkits of the same vintage) most of the components were WWII surplus.  Therefore some of the capacitors would usually have been disc ceramic rather than mica, particularly the .001 mfd which are just bypass or coupling caps and ceramics will work just fine.  The others should be easy to find.
Allen
Logged
AB2MA
Member

Posts: 47




Ignore
« Reply #6 on: March 04, 2008, 10:01:22 AM »

Tnx for all the input,I'll be able to get started on the AT-1 now.Still looking for a transformer though(425-0-425 5.0 6.3),if anyone has one and wants to sell it let me know.Stan
Logged
KL7AJ
Member

Posts: 340


WWW

Ignore
« Reply #7 on: March 06, 2008, 01:54:56 PM »

MA:

  What is the application of these caps?  If they are frequency determining components, you don't want to use ceramics.  If they're just coupling caps,,,sure.

eric
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!