30-08-2019, 11:15 AM
(This post was last modified: 30-08-2019, 11:16 AM by Mike Watterson.)
By smaller, I mean physically smaller at the SAME value.
1nF are usually X7R or better and excellent. The 3mm or smaller disc type might not be good. The 5mm approx disc ones are fine. Originally the tube type construction was used for 100V to 10,000V but later replaced by epoxy coated discs.
You can get 1uF 10V ceramic caps smaller than the tubular 1nF in TV chassis. They are often paralleled with 1nF chip caps in good design as the RF performance is poor. Also those or Z5U are never used were better than 20% accuracy needed.
You can use a 1uF as a "varicap" for low frequency oscilators or timing! Or as a vibration sensor.
Multilayer are usually inferior to single layer.
Capacitors of 0.5 pF to 1nF for tuning and oscillators are using specialised ceramics. At GHz frequencies they may be printed on teflon (PTFE) PCBs that are maybe 0.4mm thick, using a sort of cheese triangle shape. At lower frequencies square shaped print on 0.8 GRP PCB may be used. Good RF design now uses SMT as the inductance is clearly defined.
1nF are usually X7R or better and excellent. The 3mm or smaller disc type might not be good. The 5mm approx disc ones are fine. Originally the tube type construction was used for 100V to 10,000V but later replaced by epoxy coated discs.
You can get 1uF 10V ceramic caps smaller than the tubular 1nF in TV chassis. They are often paralleled with 1nF chip caps in good design as the RF performance is poor. Also those or Z5U are never used were better than 20% accuracy needed.
You can use a 1uF as a "varicap" for low frequency oscilators or timing! Or as a vibration sensor.
Multilayer are usually inferior to single layer.
Capacitors of 0.5 pF to 1nF for tuning and oscillators are using specialised ceramics. At GHz frequencies they may be printed on teflon (PTFE) PCBs that are maybe 0.4mm thick, using a sort of cheese triangle shape. At lower frequencies square shaped print on 0.8 GRP PCB may be used. Good RF design now uses SMT as the inductance is clearly defined.
