11-24-2018, 06:20 PM
Back to work on this project.
The first order of business was to restuff the third and final electrolytic can. This proved somewhat of a challenge, as this electrolytic was a Solar replacement and was made somewhat differently from the original RCA can. The original RCA cans are like Philco aluminum electrolytics except for the stud mounting; through 1938, most Philco electrolytics were mounted with clamps.
There was no way for me to feed a negative lead through the bottom of the can due to the way it was made.
I had no other suitable stud mounting electrolytic, so I decided to work with what I had.
Here it is, all apart and showing the new 10 uF Solen replacement cap:
[Image: http://www.philcoradio.com/images/phorum...T2_049.jpg]
I decided to try attaching a solder terminal on the top end of the electrolytic can. So I drilled a hole near the top of the can.
[Image: http://www.philcoradio.com/images/phorum...T2_050.jpg]
Next, I attached what will be the positive lead of the new 10 uF cap. You can see the original rubber cushion through which a new 12 gauge electric wire has been fed. I wrapped some electrical tape around the wire where it passes through the rubber cushion, since the original hole was much bigger than this wire, before feeding the wire through the cushion. With the help of hot glue, this should hold in place quite well.
[Image: http://www.philcoradio.com/images/phorum...T2_051.jpg]
Then, using a pop rivet, I attached a solder terminal to the hole which I had drilled previously, and soldered the other lead wire of the new 10 uF cap to this terminal.
[Image: http://www.philcoradio.com/images/phorum...T2_052.jpg]
The final result:
[Image: http://www.philcoradio.com/images/phorum...T2_053.jpg]
I checked it with my DMM. I had good continuity from the solder terminal to the threads of the can's stud. Then, I set the meter to read capacitance and checked the newly stuffed cap. It read 10.4 uF
Throughout the time I worked on this radio today, I had a supervisor watching me to make sure I made no mistakes:
[Image: http://www.philcoradio.com/images/phorum...T2_054.jpg]
After awhile, Виктор grew bored with watching me and took a nap.
I attached some more wires. At this point, the only thing remaining is the replacement of the resistors which made up the old multi-section Candohm.
[Image: http://www.philcoradio.com/images/phorum...T2_055.jpg]
And you can see I'm making progress. The only wires not highlighted now are those attaching to the Candohm. The power transformer leads and filament string are also not highlighted, but they are in place and hooked up on the chassis just the same.
[Image: http://www.philcoradio.com/images/phorum...T2_056.jpg]
Both the off-on-tone control and the volume control have been replaced in this radio. The volume control was replaced with a Philco control. But let's discuss the off-on-tone control a bit.
The original was 100K, open on the low end by design. When the wiper arm reached the low end, it disconnected from the resistance of the potentiometer and connected to one end of C33. The control that is in my 6T2 is a newer replacement. The switch does not have that positive "click" when the control is switched off, and the potentiometer section reads 50K, not 100K - and has continuity from end to end. So it looks like I need an off-on-tone control. I've posted an ad in the Wanted Ads section of the Phorum.
The service manual, containing the schematic is here (warning - large file - 32.1 MB).
Now a word about the Candohm. Nathan had made a suggestion in post #3, page 1, this thread:
I have a piece of aluminum, and I intend to mount terminal strips on that aluminum strip for the resistors...and then mount that assembly under the chassis in place of the Candohm.
The first order of business was to restuff the third and final electrolytic can. This proved somewhat of a challenge, as this electrolytic was a Solar replacement and was made somewhat differently from the original RCA can. The original RCA cans are like Philco aluminum electrolytics except for the stud mounting; through 1938, most Philco electrolytics were mounted with clamps.
There was no way for me to feed a negative lead through the bottom of the can due to the way it was made.
I had no other suitable stud mounting electrolytic, so I decided to work with what I had.
Here it is, all apart and showing the new 10 uF Solen replacement cap:
[Image: http://www.philcoradio.com/images/phorum...T2_049.jpg]
I decided to try attaching a solder terminal on the top end of the electrolytic can. So I drilled a hole near the top of the can.
[Image: http://www.philcoradio.com/images/phorum...T2_050.jpg]
Next, I attached what will be the positive lead of the new 10 uF cap. You can see the original rubber cushion through which a new 12 gauge electric wire has been fed. I wrapped some electrical tape around the wire where it passes through the rubber cushion, since the original hole was much bigger than this wire, before feeding the wire through the cushion. With the help of hot glue, this should hold in place quite well.
[Image: http://www.philcoradio.com/images/phorum...T2_051.jpg]
Then, using a pop rivet, I attached a solder terminal to the hole which I had drilled previously, and soldered the other lead wire of the new 10 uF cap to this terminal.
[Image: http://www.philcoradio.com/images/phorum...T2_052.jpg]
The final result:
[Image: http://www.philcoradio.com/images/phorum...T2_053.jpg]
I checked it with my DMM. I had good continuity from the solder terminal to the threads of the can's stud. Then, I set the meter to read capacitance and checked the newly stuffed cap. It read 10.4 uF
Throughout the time I worked on this radio today, I had a supervisor watching me to make sure I made no mistakes:
[Image: http://www.philcoradio.com/images/phorum...T2_054.jpg]
After awhile, Виктор grew bored with watching me and took a nap.
I attached some more wires. At this point, the only thing remaining is the replacement of the resistors which made up the old multi-section Candohm.
[Image: http://www.philcoradio.com/images/phorum...T2_055.jpg]
And you can see I'm making progress. The only wires not highlighted now are those attaching to the Candohm. The power transformer leads and filament string are also not highlighted, but they are in place and hooked up on the chassis just the same.
[Image: http://www.philcoradio.com/images/phorum...T2_056.jpg]
Both the off-on-tone control and the volume control have been replaced in this radio. The volume control was replaced with a Philco control. But let's discuss the off-on-tone control a bit.
The original was 100K, open on the low end by design. When the wiper arm reached the low end, it disconnected from the resistance of the potentiometer and connected to one end of C33. The control that is in my 6T2 is a newer replacement. The switch does not have that positive "click" when the control is switched off, and the potentiometer section reads 50K, not 100K - and has continuity from end to end. So it looks like I need an off-on-tone control. I've posted an ad in the Wanted Ads section of the Phorum.
The service manual, containing the schematic is here (warning - large file - 32.1 MB).
Now a word about the Candohm. Nathan had made a suggestion in post #3, page 1, this thread:
Nathan Slingerland Wrote:On my 37-2670 I mounted the replacement resistors on a sturdy aluminum plate, using flat-head machine screws so that the heads would be flush with the aluminum backer.
I then mounted the whole assembly using the original holes for the drilled out rivets.
I have a piece of aluminum, and I intend to mount terminal strips on that aluminum strip for the resistors...and then mount that assembly under the chassis in place of the Candohm.
--
Ron Ramirez
Ferdinand IN
