@rayma
Back in the early 90's I worked for a video projector manufacturer and they were having quality problems with shorts and opens in their motherboards. They asked their supplier to electrically test the boards before shopping (an added expense). We received a batch of 100 boards and a report that 91 had passed. They shipped us 100 boards and after populating and testing the boards we found that they were right. 9 were bad.
Back in the early 90's I worked for a video projector manufacturer and they were having quality problems with shorts and opens in their motherboards. They asked their supplier to electrically test the boards before shopping (an added expense). We received a batch of 100 boards and a report that 91 had passed. They shipped us 100 boards and after populating and testing the boards we found that they were right. 9 were bad.
Some capacitors do make good antennas. I forgot to solder one leg of a capacitor once. The circuit worked with reduced gain (it was the electrolytic in a feedback circuit), but it was picking up multiple radio stations at one time. Poking around the circuit with my finger, I noticed that if I touched one capacitor the noise got way louder. I fixed the one solder joint and it worked as intended.
I also learned to connect the capacitor to the lower impedance leg of the circuit in a filter circuit. Example if you have a capacitor and resistor in series, ground the capacitor if one leg of the circuit is grounded. If the components go between the output and inverting input, then the capacitor get connected to the output.
Yes sound advice. Also in case of a rolled film cap, where you can identify the lead to the outside of the roll, connect that to ground to shield the internals.
Jan
It might make a good WiFi or GPS antenna if you had the means to trim the lead length just right.
I spent several years in cell phone design. We were putting together a few prototype phones for field testing and we hadn't received the GPS patch antennas from the vendor.
The plan was to test without GPS, but I took a couple of paper clips cut them in half to form a "J" shape and trimmed them to match the correct frequency and impedance on a network analyzer. I stuffed them into two phones and we went about our testing.
We did some basic GPS testing on the two phones that had the paper clips, then replaced them and fitted the remaining phones with the proper antennas, then did the usual GPS testing. It seems that the bent paper clip had outperformed the proper GPS antenna by a pretty good margin. This was verified with more paper clips.
The final shipping phone got a better ceramic patch antenna, that did work better than the paper clip when held in the hand. That's where the paper clip failed to keep up.
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