Gideon Analytical Laboratories received four Spectrum Control Pi filters N49927 Bus A (capacitor components FL1, FL2, FL3, and FL4). Capacitor-input filters (also known as Pi filters) are a type of electronic filter used to remove unwanted frequencies from a signal. Pi filters are primarily constructed of two capacitors and an inductor. They are used in situations where the ripple of a signal or the AC and DC currents within the signal are found to interfere with each other.
Gideon Analytical Laboratories received several GVD30601-001 super hyperabrupt junction tuning varactor diodes with a latent failure mechanism over time. A varactor diode is a P-N junction diode that changes its capacitance and the series resistance as the bias applied to the diode is varied. Hyperabrupt tuning varactor diodes offer a large change in junction capacitance over a small tuning voltage range. Varactors are operated in a reverse-bias state, like a Zener diode.
The analysis was performed on ten failed microwave capacitors. They were Samwha vintage 2100VAC .65uF with 3 percent tolerance with a maximum temperature rating of 85oC. All the capacitors were tested for shorts or opens. The resistance of the integrated resistor was measured also. None of the integrated resistors failed. They all varied from 9.75-M ohms to 10.85M ohms. Many of the capacitors saw considerable heat. This was evident by the bulging deformed metal can housing.