03-09-2014, 03:50 PM
Yes those are the ones. They are pretty but are always leaky. As bad or worse than the waxed paper caps of the 30's and 40's.
Anytime you see those stripes you know there will be trouble. They are known as "bumble bees". Sprague made them from the late 40's to late 50's.
Later Sprague made similar looking caps with Mylar dielectric, but they printed the value on them instead of the color code. These are typically still good 50 years later.
The power supply voltage might be low because the output tubes are drawing excessive current, due to the positive leakage reducing the negative grid bias.
Anytime you see those stripes you know there will be trouble. They are known as "bumble bees". Sprague made them from the late 40's to late 50's.
Later Sprague made similar looking caps with Mylar dielectric, but they printed the value on them instead of the color code. These are typically still good 50 years later.
The power supply voltage might be low because the output tubes are drawing excessive current, due to the positive leakage reducing the negative grid bias.
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
