Thoughts (?) about tinning "tip" of stranded #12 awg wire.

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synchro said:
I imagine they had to preassemble those boards because aligning IF strips, etc. would take specialized equipment.



I put together a Hafler power amp and pre-amp. The power amp used MOSFETs on the outputs. They were biased more heavily than a normal class AB and so the heat sinks got quite warm even without any drive signal.

Did you work at an Olson Electronics parts store? Just asking, because I know they had a number of them in Ohio.
To get back to the soldering topic, at an Olson's I saw a kid returning a simple kit that he'd assembled because it didn't work. The counterman took a quick look, and then he told the kid it was because he'd soldered all the resistors in backwards. :rolleyes:
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Resistors don't have polarity. It must have been diodes. Or did I miss the joke?
 
ggunn said:
Resistors don't have polarity. It must have been diodes. Or did I miss the joke?
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It wasn't really intended as a joke, just noting the cruel reality in this world. I was a kid at the time too, but I still remember it because I knew the counterman was full of it and just wanted the kid to go away.
I also remember seeing a transistor in a bubble pack at Radio Shack where the devices it claimed to replace were both NPN's and PNP's. Maybe it worked just as well for both cases, that is, not at all.
 
PaulMmn said:
I built the Dynaco FM Tuner-- you received the chassis, some brackets, and (IIRC) 2 circuit boards and the tuning capacitor assembly. The boards were pre-loaded and soldered, and the 3 modules were factory-tested as a unit. AllI had to do was the mechanical assembly (including stringing the indicator dial). Great unit!
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The original FM Tuner kits featured empty PC boards and components to load.
The IF strip and detector were designed to be tuned to a simple signal maximum using the built-in tuning eye for signal strength measurements. The necessary detuning from maximum required for the detector stage was obtained by adding a tweaking capacitor (about 1/2' of wire) after first tuning to maximum.
The capacitance was probably a couple of picoFarads.
 
How do know when your torque screw driver is out of torque? I keep mine in the truck and bet that all the bouncing around its out of torque.
 
GoldDigger said:
The IF strip and detector were designed to be tuned to a simple signal maximum using the built-in tuning eye for signal strength measurements.
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Oh yes, the old "magic eye" tubes with a green glow.

GoldDigger said:
The necessary detuning from maximum required for the detector stage was obtained by adding a tweaking capacitor (about 1/2' of wire) after first tuning to maximum. The capacitance was probably a couple of picoFarads.
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AKA "gimmick" capacitors. A former coworker of mine said when he was young he was cleaning up an old radio and found little pieces of wire sticking out from some solder joints. Thinking it was poor workmanship he cut them all off, but then the radio stopped working. It was only later that someone explained to him that those were gimmick capacitors and they were necessary for proper operation.
 
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