12-22-2016, 09:58 PM
Six months later...
Having finished a Philco 37-640/38-624T project, it's time to turn my attention to this Sherwood once again.
A month or more ago, I ordered enough parts from Mouser to take care of the power supply in this S-7900A, along with two other stereo receivers.
The first thing I did was what I felt would be the hardest part: restuffing the two main electrolytic cans.
I unsoldered everything from them (taking notes beforehand), removed the cans, and cut them open. Here's how they looked:
[Image: http://www.philcoradio.com/images/phorum/S7900A_018.jpg]
I cut away the old electrolytic, drilled two holes in the base, and soldered two wires to the positive and negative leads of new Nichicon electrolytics. The originals were 7000 uF, 50 volts - the new ones are 8200 uF, 63 volts.
[Image: http://www.philcoradio.com/images/phorum/S7900A_019.jpg]
Then I glued the cans back together:
[Image: http://www.philcoradio.com/images/phorum/S7900A_020.jpg]
Tomorrow, once the glue dries, I'll reinstall these into the receiver. I will also be replacing the four rectifier diodes and a few other electrolytics.
This receiver not only has the death caps from each side of the line to ground, but also in the high voltage secondary winding of the power transformer. The originals in the secondary are 0.22 uF film caps (not safety caps). I'm thinking of replacing them with .01 uF safety caps. What say you, people?
Having finished a Philco 37-640/38-624T project, it's time to turn my attention to this Sherwood once again.
A month or more ago, I ordered enough parts from Mouser to take care of the power supply in this S-7900A, along with two other stereo receivers.
The first thing I did was what I felt would be the hardest part: restuffing the two main electrolytic cans.
I unsoldered everything from them (taking notes beforehand), removed the cans, and cut them open. Here's how they looked:
[Image: http://www.philcoradio.com/images/phorum/S7900A_018.jpg]
I cut away the old electrolytic, drilled two holes in the base, and soldered two wires to the positive and negative leads of new Nichicon electrolytics. The originals were 7000 uF, 50 volts - the new ones are 8200 uF, 63 volts.
[Image: http://www.philcoradio.com/images/phorum/S7900A_019.jpg]
Then I glued the cans back together:
[Image: http://www.philcoradio.com/images/phorum/S7900A_020.jpg]
Tomorrow, once the glue dries, I'll reinstall these into the receiver. I will also be replacing the four rectifier diodes and a few other electrolytics.
This receiver not only has the death caps from each side of the line to ground, but also in the high voltage secondary winding of the power transformer. The originals in the secondary are 0.22 uF film caps (not safety caps). I'm thinking of replacing them with .01 uF safety caps. What say you, people?
--
Ron Ramirez
Ferdinand IN
