Glass capacitors that look like diodes

<The "glass capacitors" that look like diodes look that way because they = <ARE diodes. It turns out that one of the cheapest and best ways to make = <0.1uF capacitors is to make two diodes in the same case, in series with = This is inaccurate. The size of the junction needed to create a .1uF cap would be huge. It would not be cheap nor effective. The cap inside is similar in construction to those now seen on SMT loaded cards. It is possible to make caps using the junction and there are devices that use this principle. However the capacitance is A) variable with voltage imposed across the reverse biased junction and B) 300-500pf is about the upper limit for them. They are known as varactor or varicap diodes and are not found on SA8XX drives. The glass caps were generally just a different package with one advantage in that glass is hermetic. Or better said compared to plastics and some ceramics they are impervious to moisture. Allison