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Just because those capacitors test good with the tester's low voltage doesn't mean they will last very long. The most common way for them to fail is to break down and short inside when full voltage has been applied for a while.

Feel free to prove this to yourself, but untold thousands of other folks have already found this out the hard way. When that kind of part gets old the internal chemistry breaks down and they fail. No real mystery. The manufacturer's specifications generally claim a service life of no more than a few thousand hours total. Feel free to check that out for yourself, too.

Good luck on the transformer. Lotsa 300A amplifiers out there with no transformers. Not so many transformers with no linear.

And 3 Amps won't cut the mustard for the amplifier's 12-Volt AC requirement. The 300A wires pairs of 6.3-Volt heaters in series. Each pair draws just over 2 Amps. That makes the total 6 Amps, not 3.

73

<blockquote data-quote="nomadradio" data-source="post: 760860" data-attributes="member: 22">Just because those capacitors test good with the tester&#039;s low voltage doesn&#039;t mean they will last very long. The most common way for them to fail is to break down and short inside when full voltage has been applied for a while. Feel free to prove this to yourself, but untold thousands of other folks have already found this out the hard way. When that kind of part gets old the internal chemistry breaks down and they fail. No real mystery. The manufacturer&#039;s specifications generally claim a service life of no more than a few thousand hours total. Feel free to check that out for yourself, too. Good luck on the transformer. Lotsa 300A amplifiers out there with no transformers. Not so many transformers with no linear. And 3 Amps won&#039;t cut the mustard for the amplifier&#039;s 12-Volt AC requirement. The 300A wires pairs of 6.3-Volt heaters in series. Each pair draws just over 2 Amps. That makes the total 6 Amps, not 3. 73</blockquote>

[QUOTE="nomadradio, post: 760860, member: 22"] Just because those capacitors test good with the tester's low voltage doesn't mean they will last very long. The most common way for them to fail is to break down and short inside when full voltage has been applied for a while. Feel free to prove this to yourself, but untold thousands of other folks have already found this out the hard way. When that kind of part gets old the internal chemistry breaks down and they fail. No real mystery. The manufacturer's specifications generally claim a service life of no more than a few thousand hours total. Feel free to check that out for yourself, too. Good luck on the transformer. Lotsa 300A amplifiers out there with no transformers. Not so many transformers with no linear. And 3 Amps won't cut the mustard for the amplifier's 12-Volt AC requirement. The 300A wires pairs of 6.3-Volt heaters in series. Each pair draws just over 2 Amps. That makes the total 6 Amps, not 3. 73 [/QUOTE]

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