Newbie capacitor question

[ApolloCAP]

Hello!
I am an electronics newbie, and I was wondering where I could find a
capacitor found at
http://www.mitedu.freeserve.co.uk/Circuits/Alarm/radiowavealm.htm . It says
I need a 4 nano farad capacitor. Could someone give me the URL of say a
mouser catalog item that's 4 nano farads?
I have mis ordered twice. I always order this useless surface-mount
capacitors. Can someone give me the catalog item or # for one with leads
that's ceramic?
Any help would be GREATLY appreciated!!!!!!!!!!
Sincerely,
Apollo_CAP

 

[Howard Henry Schlunder]

Your schematic calls for a 220 nanofarad capacitor, and also a 4 picofarad
capacitor, but not a 4 nanofarad kind. I couldn't quickly find any
thru-hole 4 picofarad ceramic kind, but I believe the 4pF mica type would
work for your application: [
http://www.mouser.com/index.cfm?handler=displayproduct&&lstdispproductid=371802 ]
.. This description has "RDL" in it, which I'm pretty sure is short for
Radial Leaded, meaning it has two leads comming out of the bottom of it.

Alternatly, you may desire to put a pair of 2pF capacitors in parallel to
have an equivalent 4pF one. [
http://www.mouser.com/index.cfm?handler=displayproduct&&lstdispproductid=308910 ]
is, I believe, a 2pF ceramic capacitor in thru-hole package.

For reference, note that all capacitors and resistors which have the number
0201, 0402, 0603, 0805, 1206, 1210, 2010, or 2512 in the description are
going to be a surface mount device.

4pF is really small as capacitor's go. In the interest of creating your
circuit and getting instant gratification (rather than waiting for another
Mouser delivery), I would take a piece of insulated wire (which is tied to
0V) and wrap part of your "sensor" (aluminum foil) around it. Having a
capacitor that is the wrong value will change the frequency of oscillation,
so your AM radio will have to be tuned to some other frequency, but maybe
you can play around and see if something happens.

Howard Henry Schlunder


"ApolloCAP" wrote in message
news:TW2Na.44073$8B.15909@twister.nyroc.rr.com...

Hello!
I am an electronics newbie, and I was wondering where I could find a
capacitor found at
http://www.mitedu.freeserve.co.uk/Circuits/Alarm/radiowavealm.htm . It
says
I need a 4 nano farad capacitor. Could someone give me the URL of say a
mouser catalog item that's 4 nano farads?
I have mis ordered twice. I always order this useless surface-mount
capacitors. Can someone give me the catalog item or # for one with leads
that's ceramic?
Any help would be GREATLY appreciated!!!!!!!!!!
Sincerely,
Apollo_CAP

-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

 

[John Popelish]

ApolloCAP wrote:

Hello!
I am an electronics newbie, and I was wondering where I could find a
capacitor found at
http://www.mitedu.freeserve.co.uk/Circuits/Alarm/radiowavealm.htm . It says
I need a 4 nano farad capacitor. Could someone give me the URL of say a
mouser catalog item that's 4 nano farads?
I have mis ordered twice. I always order this useless surface-mount
capacitors. Can someone give me the catalog item or # for one with leads
that's ceramic?
Any help would be GREATLY appreciated!!!!!!!!!!
Sincerely,
Apollo_CAP

The only capacitors I see are a 4p (4 picofarads) and a 220n (220
nanofarads). You can make your own 4p capacitor by just twisting a
pair of wires together. Try two 4 pieces of bell wire. Adjust the
capacitance (to tune the frequency by twisting tighter or looser.

--
John Popelish