Hi,
I am building this little FM transmitter:http://www.aaroncake.net/circuits/fmtrans.asp. It calls for a 5.6pf disc cap. What would the markings on a 5.6pf capacitor look like?
Thanks a lot,
AnonymousNerd

 

Since the markings are typically in picofarads, it will be marked "5.6." There is no multiplier (e.g., "0," meaning 10^0) on the ceramic caps that I have in that range.

John

 

Thanks for your help

 

One more question:
I found a 5pf disc cap. Would it work instead of the 5.6pf?
Thanks

 

One more question:
I found a 5pf disc cap. Would it work instead of the 5.6pf?
Thanks

You could try. You circuit board will not blow up like cracker because of using this small value deviation

 

5.6 pF capacitors.

Do they exist? I really doubt so.

 

Yes, 5.6 pF do exist. Try searching any supplier. Here's a DigiKey link: http://media.digikey.com/pdf/Data Sheets/Murata PDFs/RPE5C2AxxxJ2P.pdf

John

 

Just had a look in my small capacitor box, I have bags of 3, 5, 6, 7, 8, 10, 12pf (etc) in leaded ceramic disc caps. Surface mount types go somewhat lower.

When you start messing with VHF / UHF / Microwave radio gear, you tend to use quite a range of small values. (I'm a radio ham with an interest in VHF & up digital comms).

On the digital production side, we use 6.8pF as the loading caps on 20MHz oscillator crystals for gear using PICs.

Small value caps are very common in many applications.

Back to the OP, the difference between 5.0 & 5.6pF will probably be swamped by lead and circuit board capacitance, unless you are working 'dead bug' style, in which case you may need a slightly higher value than for a PCB design.

 

One more question:
I found a 5pf disc cap. Would it work instead of the 5.6pf?
Thanks

Yes a 5pF will be just fine.
Given that the average ceramic capacitor has a 20% tolerance, a 5pF will be near enough to 5.6pF for most applications.